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2024-09-18fou: fix initialization of grcMuhammad Usama Anjum
[ Upstream commit 4c8002277167125078e6b9b90137bdf443ebaa08 ] The grc must be initialize first. There can be a condition where if fou is NULL, goto out will be executed and grc would be used uninitialized. Fixes: 7e4196935069 ("fou: Fix null-ptr-deref in GRO.") Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20240906102839.202798-1-usama.anjum@collabora.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-09-12tcp: process the 3rd ACK with sk_socket for TFO/MPTCPMatthieu Baerts (NGI0)
commit c1668292689ad2ee16c9c1750a8044b0b0aad663 upstream. The 'Fixes' commit recently changed the behaviour of TCP by skipping the processing of the 3rd ACK when a sk->sk_socket is set. The goal was to skip tcp_ack_snd_check() in tcp_rcv_state_process() not to send an unnecessary ACK in case of simultaneous connect(). Unfortunately, that had an impact on TFO and MPTCP. I started to look at the impact on MPTCP, because the MPTCP CI found some issues with the MPTCP Packetdrill tests [1]. Then Paolo Abeni suggested me to look at the impact on TFO with "plain" TCP. For MPTCP, when receiving the 3rd ACK of a request adding a new path (MP_JOIN), sk->sk_socket will be set, and point to the MPTCP sock that has been created when the MPTCP connection got established before with the first path. The newly added 'goto' will then skip the processing of the segment text (step 7) and not go through tcp_data_queue() where the MPTCP options are validated, and some actions are triggered, e.g. sending the MPJ 4th ACK [2] as demonstrated by the new errors when running a packetdrill test [3] establishing a second subflow. This doesn't fully break MPTCP, mainly the 4th MPJ ACK that will be delayed. Still, we don't want to have this behaviour as it delays the switch to the fully established mode, and invalid MPTCP options in this 3rd ACK will not be caught any more. This modification also affects the MPTCP + TFO feature as well, and being the reason why the selftests started to be unstable the last few days [4]. For TFO, the existing 'basic-cookie-not-reqd' test [5] was no longer passing: if the 3rd ACK contains data, and the connection is accept()ed before receiving them, these data would no longer be processed, and thus not ACKed. One last thing about MPTCP, in case of simultaneous connect(), a fallback to TCP will be done, which seems fine: `../common/defaults.sh` 0 socket(..., SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_MPTCP) = 3 +0 connect(3, ..., ...) = -1 EINPROGRESS (Operation now in progress) +0 > S 0:0(0) <mss 1460, sackOK, TS val 100 ecr 0, nop, wscale 8, mpcapable v1 flags[flag_h] nokey> +0 < S 0:0(0) win 1000 <mss 1460, sackOK, TS val 407 ecr 0, nop, wscale 8, mpcapable v1 flags[flag_h] nokey> +0 > S. 0:0(0) ack 1 <mss 1460, sackOK, TS val 330 ecr 0, nop, wscale 8, mpcapable v1 flags[flag_h] nokey> +0 < S. 0:0(0) ack 1 win 65535 <mss 1460, sackOK, TS val 700 ecr 100, nop, wscale 8, mpcapable v1 flags[flag_h] key[skey=2]> +0 > . 1:1(0) ack 1 <nop, nop, TS val 845707014 ecr 700, nop, nop, sack 0:1> Simultaneous SYN-data crossing is also not supported by TFO, see [6]. Kuniyuki Iwashima suggested to restrict the processing to SYN+ACK only: that's a more generic solution than the one initially proposed, and also enough to fix the issues described above. Later on, Eric Dumazet mentioned that an ACK should still be sent in reaction to the second SYN+ACK that is received: not sending a DUPACK here seems wrong and could hurt: 0 socket(..., SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 3 +0 connect(3, ..., ...) = -1 EINPROGRESS (Operation now in progress) +0 > S 0:0(0) <mss 1460, sackOK, TS val 1000 ecr 0,nop,wscale 8> +0 < S 0:0(0) win 1000 <mss 1000, sackOK, nop, nop> +0 > S. 0:0(0) ack 1 <mss 1460, sackOK, TS val 3308134035 ecr 0,nop,wscale 8> +0 < S. 0:0(0) ack 1 win 1000 <mss 1000, sackOK, nop, nop> +0 > . 1:1(0) ack 1 <nop, nop, sack 0:1> // <== Here So in this version, the 'goto consume' is dropped, to always send an ACK when switching from TCP_SYN_RECV to TCP_ESTABLISHED. This ACK will be seen as a DUPACK -- with DSACK if SACK has been negotiated -- in case of simultaneous SYN crossing: that's what is expected here. Link: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/9936227696 [1] Link: https://datatracker.ietf.org/doc/html/rfc8684#fig_tokens [2] Link: https://github.com/multipath-tcp/packetdrill/blob/mptcp-net-next/gtests/net/mptcp/syscalls/accept.pkt#L28 [3] Link: https://netdev.bots.linux.dev/contest.html?executor=vmksft-mptcp-dbg&test=mptcp-connect-sh [4] Link: https://github.com/google/packetdrill/blob/master/gtests/net/tcp/fastopen/server/basic-cookie-not-reqd.pkt#L21 [5] Link: https://github.com/google/packetdrill/blob/master/gtests/net/tcp/fastopen/client/simultaneous-fast-open.pkt [6] Fixes: 23e89e8ee7be ("tcp: Don't drop SYN+ACK for simultaneous connect().") Suggested-by: Paolo Abeni <pabeni@redhat.com> Suggested-by: Kuniyuki Iwashima <kuniyu@amazon.com> Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20240724-upstream-net-next-20240716-tcp-3rd-ack-consume-sk_socket-v3-1-d48339764ce9@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-12tcp: Don't drop SYN+ACK for simultaneous connect().Kuniyuki Iwashima
[ Upstream commit 23e89e8ee7be73e21200947885a6d3a109a2c58d ] RFC 9293 states that in the case of simultaneous connect(), the connection gets established when SYN+ACK is received. [0] TCP Peer A TCP Peer B 1. CLOSED CLOSED 2. SYN-SENT --> <SEQ=100><CTL=SYN> ... 3. SYN-RECEIVED <-- <SEQ=300><CTL=SYN> <-- SYN-SENT 4. ... <SEQ=100><CTL=SYN> --> SYN-RECEIVED 5. SYN-RECEIVED --> <SEQ=100><ACK=301><CTL=SYN,ACK> ... 6. ESTABLISHED <-- <SEQ=300><ACK=101><CTL=SYN,ACK> <-- SYN-RECEIVED 7. ... <SEQ=100><ACK=301><CTL=SYN,ACK> --> ESTABLISHED However, since commit 0c24604b68fc ("tcp: implement RFC 5961 4.2"), such a SYN+ACK is dropped in tcp_validate_incoming() and responded with Challenge ACK. For example, the write() syscall in the following packetdrill script fails with -EAGAIN, and wrong SNMP stats get incremented. 0 socket(..., SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 3 +0 connect(3, ..., ...) = -1 EINPROGRESS (Operation now in progress) +0 > S 0:0(0) <mss 1460,sackOK,TS val 1000 ecr 0,nop,wscale 8> +0 < S 0:0(0) win 1000 <mss 1000> +0 > S. 0:0(0) ack 1 <mss 1460,sackOK,TS val 3308134035 ecr 0,nop,wscale 8> +0 < S. 0:0(0) ack 1 win 1000 +0 write(3, ..., 100) = 100 +0 > P. 1:101(100) ack 1 -- # packetdrill cross-synack.pkt cross-synack.pkt:13: runtime error in write call: Expected result 100 but got -1 with errno 11 (Resource temporarily unavailable) # nstat ... TcpExtTCPChallengeACK 1 0.0 TcpExtTCPSYNChallenge 1 0.0 The problem is that bpf_skops_established() is triggered by the Challenge ACK instead of SYN+ACK. This causes the bpf prog to miss the chance to check if the peer supports a TCP option that is expected to be exchanged in SYN and SYN+ACK. Let's accept a bare SYN+ACK for active-open TCP_SYN_RECV sockets to avoid such a situation. Note that tcp_ack_snd_check() in tcp_rcv_state_process() is skipped not to send an unnecessary ACK, but this could be a bit risky for net.git, so this targets for net-next. Link: https://www.rfc-editor.org/rfc/rfc9293.html#section-3.5-7 [0] Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20240710171246.87533-2-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-09-12fou: Fix null-ptr-deref in GRO.Kuniyuki Iwashima
[ Upstream commit 7e4196935069947d8b70b09c1660b67b067e75cb ] We observed a null-ptr-deref in fou_gro_receive() while shutting down a host. [0] The NULL pointer is sk->sk_user_data, and the offset 8 is of protocol in struct fou. When fou_release() is called due to netns dismantle or explicit tunnel teardown, udp_tunnel_sock_release() sets NULL to sk->sk_user_data. Then, the tunnel socket is destroyed after a single RCU grace period. So, in-flight udp4_gro_receive() could find the socket and execute the FOU GRO handler, where sk->sk_user_data could be NULL. Let's use rcu_dereference_sk_user_data() in fou_from_sock() and add NULL checks in FOU GRO handlers. [0]: BUG: kernel NULL pointer dereference, address: 0000000000000008 PF: supervisor read access in kernel mode PF: error_code(0x0000) - not-present page PGD 80000001032f4067 P4D 80000001032f4067 PUD 103240067 PMD 0 SMP PTI CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.10.216-204.855.amzn2.x86_64 #1 Hardware name: Amazon EC2 c5.large/, BIOS 1.0 10/16/2017 RIP: 0010:fou_gro_receive (net/ipv4/fou.c:233) [fou] Code: 41 5f c3 cc cc cc cc e8 e7 2e 69 f4 0f 1f 80 00 00 00 00 0f 1f 44 00 00 49 89 f8 41 54 48 89 f7 48 89 d6 49 8b 80 88 02 00 00 <0f> b6 48 08 0f b7 42 4a 66 25 fd fd 80 cc 02 66 89 42 4a 0f b6 42 RSP: 0018:ffffa330c0003d08 EFLAGS: 00010297 RAX: 0000000000000000 RBX: ffff93d9e3a6b900 RCX: 0000000000000010 RDX: ffff93d9e3a6b900 RSI: ffff93d9e3a6b900 RDI: ffff93dac2e24d08 RBP: ffff93d9e3a6b900 R08: ffff93dacbce6400 R09: 0000000000000002 R10: 0000000000000000 R11: ffffffffb5f369b0 R12: ffff93dacbce6400 R13: ffff93dac2e24d08 R14: 0000000000000000 R15: ffffffffb4edd1c0 FS: 0000000000000000(0000) GS:ffff93daee800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000008 CR3: 0000000102140001 CR4: 00000000007706f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <IRQ> ? show_trace_log_lvl (arch/x86/kernel/dumpstack.c:259) ? __die_body.cold (arch/x86/kernel/dumpstack.c:478 arch/x86/kernel/dumpstack.c:420) ? no_context (arch/x86/mm/fault.c:752) ? exc_page_fault (arch/x86/include/asm/irqflags.h:49 arch/x86/include/asm/irqflags.h:89 arch/x86/mm/fault.c:1435 arch/x86/mm/fault.c:1483) ? asm_exc_page_fault (arch/x86/include/asm/idtentry.h:571) ? fou_gro_receive (net/ipv4/fou.c:233) [fou] udp_gro_receive (include/linux/netdevice.h:2552 net/ipv4/udp_offload.c:559) udp4_gro_receive (net/ipv4/udp_offload.c:604) inet_gro_receive (net/ipv4/af_inet.c:1549 (discriminator 7)) dev_gro_receive (net/core/dev.c:6035 (discriminator 4)) napi_gro_receive (net/core/dev.c:6170) ena_clean_rx_irq (drivers/amazon/net/ena/ena_netdev.c:1558) [ena] ena_io_poll (drivers/amazon/net/ena/ena_netdev.c:1742) [ena] napi_poll (net/core/dev.c:6847) net_rx_action (net/core/dev.c:6917) __do_softirq (arch/x86/include/asm/jump_label.h:25 include/linux/jump_label.h:200 include/trace/events/irq.h:142 kernel/softirq.c:299) asm_call_irq_on_stack (arch/x86/entry/entry_64.S:809) </IRQ> do_softirq_own_stack (arch/x86/include/asm/irq_stack.h:27 arch/x86/include/asm/irq_stack.h:77 arch/x86/kernel/irq_64.c:77) irq_exit_rcu (kernel/softirq.c:393 kernel/softirq.c:423 kernel/softirq.c:435) common_interrupt (arch/x86/kernel/irq.c:239) asm_common_interrupt (arch/x86/include/asm/idtentry.h:626) RIP: 0010:acpi_idle_do_entry (arch/x86/include/asm/irqflags.h:49 arch/x86/include/asm/irqflags.h:89 drivers/acpi/processor_idle.c:114 drivers/acpi/processor_idle.c:575) Code: 8b 15 d1 3c c4 02 ed c3 cc cc cc cc 65 48 8b 04 25 40 ef 01 00 48 8b 00 a8 08 75 eb 0f 1f 44 00 00 0f 00 2d d5 09 55 00 fb f4 <fa> c3 cc cc cc cc e9 be fc ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffffffffb5603e58 EFLAGS: 00000246 RAX: 0000000000004000 RBX: ffff93dac0929c00 RCX: ffff93daee833900 RDX: ffff93daee800000 RSI: ffff93daee87dc00 RDI: ffff93daee87dc64 RBP: 0000000000000001 R08: ffffffffb5e7b6c0 R09: 0000000000000044 R10: ffff93daee831b04 R11: 00000000000001cd R12: 0000000000000001 R13: ffffffffb5e7b740 R14: 0000000000000001 R15: 0000000000000000 ? sched_clock_cpu (kernel/sched/clock.c:371) acpi_idle_enter (drivers/acpi/processor_idle.c:712 (discriminator 3)) cpuidle_enter_state (drivers/cpuidle/cpuidle.c:237) cpuidle_enter (drivers/cpuidle/cpuidle.c:353) cpuidle_idle_call (kernel/sched/idle.c:158 kernel/sched/idle.c:239) do_idle (kernel/sched/idle.c:302) cpu_startup_entry (kernel/sched/idle.c:395 (discriminator 1)) start_kernel (init/main.c:1048) secondary_startup_64_no_verify (arch/x86/kernel/head_64.S:310) Modules linked in: udp_diag tcp_diag inet_diag nft_nat ipip tunnel4 dummy fou ip_tunnel nft_masq nft_chain_nat nf_nat wireguard nft_ct curve25519_x86_64 libcurve25519_generic nf_conntrack libchacha20poly1305 nf_defrag_ipv6 nf_defrag_ipv4 nft_objref chacha_x86_64 nft_counter nf_tables nfnetlink poly1305_x86_64 ip6_udp_tunnel udp_tunnel libchacha crc32_pclmul ghash_clmulni_intel aesni_intel crypto_simd cryptd glue_helper mousedev psmouse button ena ptp pps_core crc32c_intel CR2: 0000000000000008 Fixes: d92283e338f6 ("fou: change to use UDP socket GRO") Reported-by: Alphonse Kurian <alkurian@amazon.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20240902173927.62706-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-09-12tcp_bpf: fix return value of tcp_bpf_sendmsg()Cong Wang
commit fe1910f9337bd46a9343967b547ccab26b4b2c6e upstream. When we cork messages in psock->cork, the last message triggers the flushing will result in sending a sk_msg larger than the current message size. In this case, in tcp_bpf_send_verdict(), 'copied' becomes negative at least in the following case: 468 case __SK_DROP: 469 default: 470 sk_msg_free_partial(sk, msg, tosend); 471 sk_msg_apply_bytes(psock, tosend); 472 *copied -= (tosend + delta); // <==== HERE 473 return -EACCES; Therefore, it could lead to the following BUG with a proper value of 'copied' (thanks to syzbot). We should not use negative 'copied' as a return value here. ------------[ cut here ]------------ kernel BUG at net/socket.c:733! Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP Modules linked in: CPU: 0 UID: 0 PID: 3265 Comm: syz-executor510 Not tainted 6.11.0-rc3-syzkaller-00060-gd07b43284ab3 #0 Hardware name: linux,dummy-virt (DT) pstate: 61400009 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) pc : sock_sendmsg_nosec net/socket.c:733 [inline] pc : sock_sendmsg_nosec net/socket.c:728 [inline] pc : __sock_sendmsg+0x5c/0x60 net/socket.c:745 lr : sock_sendmsg_nosec net/socket.c:730 [inline] lr : __sock_sendmsg+0x54/0x60 net/socket.c:745 sp : ffff800088ea3b30 x29: ffff800088ea3b30 x28: fbf00000062bc900 x27: 0000000000000000 x26: ffff800088ea3bc0 x25: ffff800088ea3bc0 x24: 0000000000000000 x23: f9f00000048dc000 x22: 0000000000000000 x21: ffff800088ea3d90 x20: f9f00000048dc000 x19: ffff800088ea3d90 x18: 0000000000000001 x17: 0000000000000000 x16: 0000000000000000 x15: 000000002002ffaf x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: ffff8000815849c0 x9 : ffff8000815b49c0 x8 : 0000000000000000 x7 : 000000000000003f x6 : 0000000000000000 x5 : 00000000000007e0 x4 : fff07ffffd239000 x3 : fbf00000062bc900 x2 : 0000000000000000 x1 : 0000000000000000 x0 : 00000000fffffdef Call trace: sock_sendmsg_nosec net/socket.c:733 [inline] __sock_sendmsg+0x5c/0x60 net/socket.c:745 ____sys_sendmsg+0x274/0x2ac net/socket.c:2597 ___sys_sendmsg+0xac/0x100 net/socket.c:2651 __sys_sendmsg+0x84/0xe0 net/socket.c:2680 __do_sys_sendmsg net/socket.c:2689 [inline] __se_sys_sendmsg net/socket.c:2687 [inline] __arm64_sys_sendmsg+0x24/0x30 net/socket.c:2687 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x48/0x110 arch/arm64/kernel/syscall.c:49 el0_svc_common.constprop.0+0x40/0xe0 arch/arm64/kernel/syscall.c:132 do_el0_svc+0x1c/0x28 arch/arm64/kernel/syscall.c:151 el0_svc+0x34/0xec arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x100/0x12c arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x19c/0x1a0 arch/arm64/kernel/entry.S:598 Code: f9404463 d63f0060 3108441f 54fffe81 (d4210000) ---[ end trace 0000000000000000 ]--- Fixes: 4f738adba30a ("bpf: create tcp_bpf_ulp allowing BPF to monitor socket TX/RX data") Reported-by: syzbot+58c03971700330ce14d8@syzkaller.appspotmail.com Cc: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Cong Wang <cong.wang@bytedance.com> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://patch.msgid.link/20240821030744.320934-1-xiyou.wangcong@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-09-08net: remove NULL-pointer net parameter in ip_metrics_convertJason Xing
[ Upstream commit 61e2bbafb00e4b9a5de45e6448a7b6b818658576 ] When I was doing some experiments, I found that when using the first parameter, namely, struct net, in ip_metrics_convert() always triggers NULL pointer crash. Then I digged into this part, realizing that we can remove this one due to its uselessness. Signed-off-by: Jason Xing <kernelxing@tencent.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-29tcp: do not export tcp_twsk_purge()Eric Dumazet
commit c51db4ac10d57c366f9a92121e3889bfc6c324cd upstream. After commit 1eeb50435739 ("tcp/dccp: do not care about families in inet_twsk_purge()") tcp_twsk_purge() is no longer potentially called from a module. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-29udp: fix receiving fraglist GSO packetsFelix Fietkau
[ Upstream commit b128ed5ab27330deeeaf51ea8bb69f1442a96f7f ] When assembling fraglist GSO packets, udp4_gro_complete does not set skb->csum_start, which makes the extra validation in __udp_gso_segment fail. Fixes: 89add40066f9 ("net: drop bad gso csum_start and offset in virtio_net_hdr") Signed-off-by: Felix Fietkau <nbd@nbd.name> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20240819150621.59833-1-nbd@nbd.name Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-29tcp: prevent concurrent execution of tcp_sk_exit_batchFlorian Westphal
[ Upstream commit 565d121b69980637f040eb4d84289869cdaabedf ] Its possible that two threads call tcp_sk_exit_batch() concurrently, once from the cleanup_net workqueue, once from a task that failed to clone a new netns. In the latter case, error unwinding calls the exit handlers in reverse order for the 'failed' netns. tcp_sk_exit_batch() calls tcp_twsk_purge(). Problem is that since commit b099ce2602d8 ("net: Batch inet_twsk_purge"), this function picks up twsk in any dying netns, not just the one passed in via exit_batch list. This means that the error unwind of setup_net() can "steal" and destroy timewait sockets belonging to the exiting netns. This allows the netns exit worker to proceed to call WARN_ON_ONCE(!refcount_dec_and_test(&net->ipv4.tcp_death_row.tw_refcount)); without the expected 1 -> 0 transition, which then splats. At same time, error unwind path that is also running inet_twsk_purge() will splat as well: WARNING: .. at lib/refcount.c:31 refcount_warn_saturate+0x1ed/0x210 ... refcount_dec include/linux/refcount.h:351 [inline] inet_twsk_kill+0x758/0x9c0 net/ipv4/inet_timewait_sock.c:70 inet_twsk_deschedule_put net/ipv4/inet_timewait_sock.c:221 inet_twsk_purge+0x725/0x890 net/ipv4/inet_timewait_sock.c:304 tcp_sk_exit_batch+0x1c/0x170 net/ipv4/tcp_ipv4.c:3522 ops_exit_list+0x128/0x180 net/core/net_namespace.c:178 setup_net+0x714/0xb40 net/core/net_namespace.c:375 copy_net_ns+0x2f0/0x670 net/core/net_namespace.c:508 create_new_namespaces+0x3ea/0xb10 kernel/nsproxy.c:110 ... because refcount_dec() of tw_refcount unexpectedly dropped to 0. This doesn't seem like an actual bug (no tw sockets got lost and I don't see a use-after-free) but as erroneous trigger of debug check. Add a mutex to force strict ordering: the task that calls tcp_twsk_purge() blocks other task from doing final _dec_and_test before mutex-owner has removed all tw sockets of dying netns. Fixes: e9bd0cca09d1 ("tcp: Don't allocate tcp_death_row outside of struct netns_ipv4.") Reported-by: syzbot+8ea26396ff85d23a8929@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/0000000000003a5292061f5e4e19@google.com/ Link: https://lore.kernel.org/netdev/20240812140104.GA21559@breakpoint.cc/ Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20240812222857.29837-1-fw@strlen.de Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-29tcp/dccp: do not care about families in inet_twsk_purge()Eric Dumazet
[ Upstream commit 1eeb5043573981f3a1278876515851b7f6b1df1b ] We lost ability to unload ipv6 module a long time ago. Instead of calling expensive inet_twsk_purge() twice, we can handle all families in one round. Also remove an extra line added in my prior patch, per Kuniyuki Iwashima feedback. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/netdev/20240327192934.6843-1-kuniyu@amazon.com/ Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20240329153203.345203-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Stable-dep-of: 565d121b6998 ("tcp: prevent concurrent execution of tcp_sk_exit_batch") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-29tcp/dccp: bypass empty buckets in inet_twsk_purge()Eric Dumazet
[ Upstream commit 50e2907ef8bb52cf80ecde9eec5c4dac07177146 ] TCP ehash table is often sparsely populated. inet_twsk_purge() spends too much time calling cond_resched(). This patch can reduce time spent in inet_twsk_purge() by 20x. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20240327191206.508114-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Stable-dep-of: 565d121b6998 ("tcp: prevent concurrent execution of tcp_sk_exit_batch") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-29tcp: Update window clamping conditionSubash Abhinov Kasiviswanathan
[ Upstream commit a2cbb1603943281a604f5adc48079a148db5cb0d ] This patch is based on the discussions between Neal Cardwell and Eric Dumazet in the link https://lore.kernel.org/netdev/20240726204105.1466841-1-quic_subashab@quicinc.com/ It was correctly pointed out that tp->window_clamp would not be updated in cases where net.ipv4.tcp_moderate_rcvbuf=0 or if (copied <= tp->rcvq_space.space). While it is expected for most setups to leave the sysctl enabled, the latter condition may not end up hitting depending on the TCP receive queue size and the pattern of arriving data. The updated check should be hit only on initial MSS update from TCP_MIN_MSS to measured MSS value and subsequently if there was an update to a larger value. Fixes: 05f76b2d634e ("tcp: Adjust clamping window for applications specifying SO_RCVBUF") Signed-off-by: Sean Tranchetti <quic_stranche@quicinc.com> Signed-off-by: Subash Abhinov Kasiviswanathan <quic_subashab@quicinc.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-19fou: remove warn in gue_gro_receive on unsupported protocolWillem de Bruijn
[ Upstream commit dd89a81d850fa9a65f67b4527c0e420d15bf836c ] Drop the WARN_ON_ONCE inn gue_gro_receive if the encapsulated type is not known or does not have a GRO handler. Such a packet is easily constructed. Syzbot generates them and sets off this warning. Remove the warning as it is expected and not actionable. The warning was previously reduced from WARN_ON to WARN_ON_ONCE in commit 270136613bf7 ("fou: Do WARN_ON_ONCE in gue_gro_receive for bad proto callbacks"). Signed-off-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20240614122552.1649044-1-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-19tcp_metrics: optimize tcp_metrics_flush_all()Eric Dumazet
[ Upstream commit 6532e257aa73645e28dee5b2232cc3c88be62083 ] This is inspired by several syzbot reports where tcp_metrics_flush_all() was seen in the traces. We can avoid acquiring tcp_metrics_lock for empty buckets, and we should add one cond_resched() to break potential long loops. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-14net: drop bad gso csum_start and offset in virtio_net_hdrWillem de Bruijn
commit 89add40066f9ed9abe5f7f886fe5789ff7e0c50e upstream. Tighten csum_start and csum_offset checks in virtio_net_hdr_to_skb for GSO packets. The function already checks that a checksum requested with VIRTIO_NET_HDR_F_NEEDS_CSUM is in skb linear. But for GSO packets this might not hold for segs after segmentation. Syzkaller demonstrated to reach this warning in skb_checksum_help offset = skb_checksum_start_offset(skb); ret = -EINVAL; if (WARN_ON_ONCE(offset >= skb_headlen(skb))) By injecting a TSO packet: WARNING: CPU: 1 PID: 3539 at net/core/dev.c:3284 skb_checksum_help+0x3d0/0x5b0 ip_do_fragment+0x209/0x1b20 net/ipv4/ip_output.c:774 ip_finish_output_gso net/ipv4/ip_output.c:279 [inline] __ip_finish_output+0x2bd/0x4b0 net/ipv4/ip_output.c:301 iptunnel_xmit+0x50c/0x930 net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0x2296/0x2c70 net/ipv4/ip_tunnel.c:813 __gre_xmit net/ipv4/ip_gre.c:469 [inline] ipgre_xmit+0x759/0xa60 net/ipv4/ip_gre.c:661 __netdev_start_xmit include/linux/netdevice.h:4850 [inline] netdev_start_xmit include/linux/netdevice.h:4864 [inline] xmit_one net/core/dev.c:3595 [inline] dev_hard_start_xmit+0x261/0x8c0 net/core/dev.c:3611 __dev_queue_xmit+0x1b97/0x3c90 net/core/dev.c:4261 packet_snd net/packet/af_packet.c:3073 [inline] The geometry of the bad input packet at tcp_gso_segment: [ 52.003050][ T8403] skb len=12202 headroom=244 headlen=12093 tailroom=0 [ 52.003050][ T8403] mac=(168,24) mac_len=24 net=(192,52) trans=244 [ 52.003050][ T8403] shinfo(txflags=0 nr_frags=1 gso(size=1552 type=3 segs=0)) [ 52.003050][ T8403] csum(0x60000c7 start=199 offset=1536 ip_summed=3 complete_sw=0 valid=0 level=0) Mitigate with stricter input validation. csum_offset: for GSO packets, deduce the correct value from gso_type. This is already done for USO. Extend it to TSO. Let UFO be: udp[46]_ufo_fragment ignores these fields and always computes the checksum in software. csum_start: finding the real offset requires parsing to the transport header. Do not add a parser, use existing segmentation parsing. Thanks to SKB_GSO_DODGY, that also catches bad packets that are hw offloaded. Again test both TSO and USO. Do not test UFO for the above reason, and do not test UDP tunnel offload. GSO packet are almost always CHECKSUM_PARTIAL. USO packets may be CHECKSUM_NONE since commit 10154dbded6d6 ("udp: Allow GSO transmit from devices with no checksum offload"), but then still these fields are initialized correctly in udp4_hwcsum/udp6_hwcsum_outgoing. So no need to test for ip_summed == CHECKSUM_PARTIAL first. This revises an existing fix mentioned in the Fixes tag, which broke small packets with GSO offload, as detected by kselftests. Link: https://syzkaller.appspot.com/bug?extid=e1db31216c789f552871 Link: https://lore.kernel.org/netdev/20240723223109.2196886-1-kuba@kernel.org Fixes: e269d79c7d35 ("net: missing check virtio") Cc: stable@vger.kernel.org Signed-off-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20240729201108.1615114-1-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-11netfilter: iptables: Fix null-ptr-deref in iptable_nat_table_init().Kuniyuki Iwashima
[ Upstream commit 5830aa863981d43560748aa93589c0695191d95d ] We had a report that iptables-restore sometimes triggered null-ptr-deref at boot time. [0] The problem is that iptable_nat_table_init() is exposed to user space before the kernel fully initialises netns. In the small race window, a user could call iptable_nat_table_init() that accesses net_generic(net, iptable_nat_net_id), which is available only after registering iptable_nat_net_ops. Let's call register_pernet_subsys() before xt_register_template(). [0]: bpfilter: Loaded bpfilter_umh pid 11702 Started bpfilter BUG: kernel NULL pointer dereference, address: 0000000000000013 PF: supervisor write access in kernel mode PF: error_code(0x0002) - not-present page PGD 0 P4D 0 PREEMPT SMP NOPTI CPU: 2 PID: 11879 Comm: iptables-restor Not tainted 6.1.92-99.174.amzn2023.x86_64 #1 Hardware name: Amazon EC2 c6i.4xlarge/, BIOS 1.0 10/16/2017 RIP: 0010:iptable_nat_table_init (net/ipv4/netfilter/iptable_nat.c:87 net/ipv4/netfilter/iptable_nat.c:121) iptable_nat Code: 10 4c 89 f6 48 89 ef e8 0b 19 bb ff 41 89 c4 85 c0 75 38 41 83 c7 01 49 83 c6 28 41 83 ff 04 75 dc 48 8b 44 24 08 48 8b 0c 24 <48> 89 08 4c 89 ef e8 a2 3b a2 cf 48 83 c4 10 44 89 e0 5b 5d 41 5c RSP: 0018:ffffbef902843cd0 EFLAGS: 00010246 RAX: 0000000000000013 RBX: ffff9f4b052caa20 RCX: ffff9f4b20988d80 RDX: 0000000000000000 RSI: 0000000000000064 RDI: ffffffffc04201c0 RBP: ffff9f4b29394000 R08: ffff9f4b07f77258 R09: ffff9f4b07f77240 R10: 0000000000000000 R11: ffff9f4b09635388 R12: 0000000000000000 R13: ffff9f4b1a3c6c00 R14: ffff9f4b20988e20 R15: 0000000000000004 FS: 00007f6284340000(0000) GS:ffff9f51fe280000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000013 CR3: 00000001d10a6005 CR4: 00000000007706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> ? show_trace_log_lvl (arch/x86/kernel/dumpstack.c:259) ? show_trace_log_lvl (arch/x86/kernel/dumpstack.c:259) ? xt_find_table_lock (net/netfilter/x_tables.c:1259) ? __die_body.cold (arch/x86/kernel/dumpstack.c:478 arch/x86/kernel/dumpstack.c:420) ? page_fault_oops (arch/x86/mm/fault.c:727) ? exc_page_fault (./arch/x86/include/asm/irqflags.h:40 ./arch/x86/include/asm/irqflags.h:75 arch/x86/mm/fault.c:1470 arch/x86/mm/fault.c:1518) ? asm_exc_page_fault (./arch/x86/include/asm/idtentry.h:570) ? iptable_nat_table_init (net/ipv4/netfilter/iptable_nat.c:87 net/ipv4/netfilter/iptable_nat.c:121) iptable_nat xt_find_table_lock (net/netfilter/x_tables.c:1259) xt_request_find_table_lock (net/netfilter/x_tables.c:1287) get_info (net/ipv4/netfilter/ip_tables.c:965) ? security_capable (security/security.c:809 (discriminator 13)) ? ns_capable (kernel/capability.c:376 kernel/capability.c:397) ? do_ipt_get_ctl (net/ipv4/netfilter/ip_tables.c:1656) ? bpfilter_send_req (net/bpfilter/bpfilter_kern.c:52) bpfilter nf_getsockopt (net/netfilter/nf_sockopt.c:116) ip_getsockopt (net/ipv4/ip_sockglue.c:1827) __sys_getsockopt (net/socket.c:2327) __x64_sys_getsockopt (net/socket.c:2342 net/socket.c:2339 net/socket.c:2339) do_syscall_64 (arch/x86/entry/common.c:51 arch/x86/entry/common.c:81) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) RIP: 0033:0x7f62844685ee Code: 48 8b 0d 45 28 0f 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 0a c3 66 0f 1f 84 00 00 00 00 00 48 8b 15 09 RSP: 002b:00007ffd1f83d638 EFLAGS: 00000246 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 00007ffd1f83d680 RCX: 00007f62844685ee RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 0000000000000004 R08: 00007ffd1f83d670 R09: 0000558798ffa2a0 R10: 00007ffd1f83d680 R11: 0000000000000246 R12: 00007ffd1f83e3b2 R13: 00007f628455baa0 R14: 00007ffd1f83d7b0 R15: 00007f628457a008 </TASK> Modules linked in: iptable_nat(+) bpfilter rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache veth xt_state xt_connmark xt_nat xt_statistic xt_MASQUERADE xt_mark xt_addrtype ipt_REJECT nf_reject_ipv4 nft_chain_nat nf_nat xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 xt_comment nft_compat nf_tables nfnetlink overlay nls_ascii nls_cp437 vfat fat ghash_clmulni_intel aesni_intel ena crypto_simd ptp cryptd i8042 pps_core serio button sunrpc sch_fq_codel configfs loop dm_mod fuse dax dmi_sysfs crc32_pclmul crc32c_intel efivarfs CR2: 0000000000000013 Fixes: fdacd57c79b7 ("netfilter: x_tables: never register tables by default") Reported-by: Takahiro Kawahara <takawaha@amazon.co.jp> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-11tcp: Adjust clamping window for applications specifying SO_RCVBUFSubash Abhinov Kasiviswanathan
[ Upstream commit 05f76b2d634e65ab34472802d9b142ea9e03f74e ] tp->scaling_ratio is not updated based on skb->len/skb->truesize once SO_RCVBUF is set leading to the maximum window scaling to be 25% of rcvbuf after commit dfa2f0483360 ("tcp: get rid of sysctl_tcp_adv_win_scale") and 50% of rcvbuf after commit 697a6c8cec03 ("tcp: increase the default TCP scaling ratio"). 50% tries to emulate the behavior of older kernels using sysctl_tcp_adv_win_scale with default value. Systems which were using a different values of sysctl_tcp_adv_win_scale in older kernels ended up seeing reduced download speeds in certain cases as covered in https://lists.openwall.net/netdev/2024/05/15/13 While the sysctl scheme is no longer acceptable, the value of 50% is a bit conservative when the skb->len/skb->truesize ratio is later determined to be ~0.66. Applications not specifying SO_RCVBUF update the window scaling and the receiver buffer every time data is copied to userspace. This computation is now used for applications setting SO_RCVBUF to update the maximum window scaling while ensuring that the receive buffer is within the application specified limit. Fixes: dfa2f0483360 ("tcp: get rid of sysctl_tcp_adv_win_scale") Signed-off-by: Sean Tranchetti <quic_stranche@quicinc.com> Signed-off-by: Subash Abhinov Kasiviswanathan <quic_subashab@quicinc.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-11tcp: annotate data-races around tp->window_clampEric Dumazet
[ Upstream commit f410cbea9f3d2675b4c8e52af1d1985b11b387d1 ] tp->window_clamp can be read locklessly, add READ_ONCE() and WRITE_ONCE() annotations. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Link: https://lore.kernel.org/r/20240404114231.2195171-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Stable-dep-of: 05f76b2d634e ("tcp: Adjust clamping window for applications specifying SO_RCVBUF") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03net: nexthop: Initialize all fields in dumped nexthopsPetr Machata
[ Upstream commit 6d745cd0e9720282cd291d36b9db528aea18add2 ] struct nexthop_grp contains two reserved fields that are not initialized by nla_put_nh_group(), and carry garbage. This can be observed e.g. with strace (edited for clarity): # ip nexthop add id 1 dev lo # ip nexthop add id 101 group 1 # strace -e recvmsg ip nexthop get id 101 ... recvmsg(... [{nla_len=12, nla_type=NHA_GROUP}, [{id=1, weight=0, resvd1=0x69, resvd2=0x67}]] ...) = 52 The fields are reserved and therefore not currently used. But as they are, they leak kernel memory, and the fact they are not just zero complicates repurposing of the fields for new ends. Initialize the full structure. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03ipv4: Fix incorrect source address in Record Route optionIdo Schimmel
[ Upstream commit cc73bbab4b1fb8a4f53a24645871dafa5f81266a ] The Record Route IP option records the addresses of the routers that routed the packet. In the case of forwarded packets, the kernel performs a route lookup via fib_lookup() and fills in the preferred source address of the matched route. The lookup is performed with the DS field of the forwarded packet, but using the RT_TOS() macro which only masks one of the two ECN bits. If the packet is ECT(0) or CE, the matched route might be different than the route via which the packet was forwarded as the input path masks both of the ECN bits, resulting in the wrong address being filled in the Record Route option. Fix by masking both of the ECN bits. Fixes: 8e36360ae876 ("ipv4: Remove route key identity dependencies in ip_rt_get_source().") Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Guillaume Nault <gnault@redhat.com> Link: https://patch.msgid.link/20240718123407.434778-1-idosch@nvidia.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03ipv4: fix source address selection with route leakNicolas Dichtel
commit 6807352353561187a718e87204458999dbcbba1b upstream. By default, an address assigned to the output interface is selected when the source address is not specified. This is problematic when a route, configured in a vrf, uses an interface from another vrf (aka route leak). The original vrf does not own the selected source address. Let's add a check against the output interface and call the appropriate function to select the source address. CC: stable@vger.kernel.org Fixes: 8cbb512c923d ("net: Add source address lookup op for VRF") Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20240710081521.3809742-2-nicolas.dichtel@6wind.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-08-03ipv4: Fix incorrect TOS in fibmatch route get replyIdo Schimmel
[ Upstream commit f036e68212c11e5a7edbb59b5e25299341829485 ] The TOS value that is returned to user space in the route get reply is the one with which the lookup was performed ('fl4->flowi4_tos'). This is fine when the matched route is configured with a TOS as it would not match if its TOS value did not match the one with which the lookup was performed. However, matching on TOS is only performed when the route's TOS is not zero. It is therefore possible to have the kernel incorrectly return a non-zero TOS: # ip link add name dummy1 up type dummy # ip address add 192.0.2.1/24 dev dummy1 # ip route get fibmatch 192.0.2.2 tos 0xfc 192.0.2.0/24 tos 0x1c dev dummy1 proto kernel scope link src 192.0.2.1 Fix by instead returning the DSCP field from the FIB result structure which was populated during the route lookup. Output after the patch: # ip link add name dummy1 up type dummy # ip address add 192.0.2.1/24 dev dummy1 # ip route get fibmatch 192.0.2.2 tos 0xfc 192.0.2.0/24 dev dummy1 proto kernel scope link src 192.0.2.1 Extend the existing selftests to not only verify that the correct route is returned, but that it is also returned with correct "tos" value (or without it). Fixes: b61798130f1b ("net: ipv4: RTM_GETROUTE: return matched fib result when requested") Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03ipv4: Fix incorrect TOS in route get replyIdo Schimmel
[ Upstream commit 338bb57e4c2a1c2c6fc92f9c0bd35be7587adca7 ] The TOS value that is returned to user space in the route get reply is the one with which the lookup was performed ('fl4->flowi4_tos'). This is fine when the matched route is configured with a TOS as it would not match if its TOS value did not match the one with which the lookup was performed. However, matching on TOS is only performed when the route's TOS is not zero. It is therefore possible to have the kernel incorrectly return a non-zero TOS: # ip link add name dummy1 up type dummy # ip address add 192.0.2.1/24 dev dummy1 # ip route get 192.0.2.2 tos 0xfc 192.0.2.2 tos 0x1c dev dummy1 src 192.0.2.1 uid 0 cache Fix by adding a DSCP field to the FIB result structure (inside an existing 4 bytes hole), populating it in the route lookup and using it when filling the route get reply. Output after the patch: # ip link add name dummy1 up type dummy # ip address add 192.0.2.1/24 dev dummy1 # ip route get 192.0.2.2 tos 0xfc 192.0.2.2 dev dummy1 src 192.0.2.1 uid 0 cache Fixes: 1a00fee4ffb2 ("ipv4: Remove rt_key_{src,dst,tos} from struct rtable.") Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03tcp: fix races in tcp_v[46]_err()Eric Dumazet
[ Upstream commit fde6f897f2a184546bf5516ac736523ef24dc6a7 ] These functions have races when they: 1) Write sk->sk_err 2) call sk_error_report(sk) 3) call tcp_done(sk) As described in prior patches in this series: An smp_wmb() is missing. We should call tcp_done() before sk_error_report(sk) to have consistent tcp_poll() results on SMP hosts. Use tcp_done_with_error() where we centralized the correct sequence. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Link: https://lore.kernel.org/r/20240528125253.1966136-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03tcp: fix race in tcp_write_err()Eric Dumazet
[ Upstream commit 853c3bd7b7917670224c9fe5245bd045cac411dd ] I noticed flakes in a packetdrill test, expecting an epoll_wait() to return EPOLLERR | EPOLLHUP on a failed connect() attempt, after multiple SYN retransmits. It sometimes return EPOLLERR only. The issue is that tcp_write_err(): 1) writes an error in sk->sk_err, 2) calls sk_error_report(), 3) then calls tcp_done(). tcp_done() is writing SHUTDOWN_MASK into sk->sk_shutdown, among other things. Problem is that the awaken user thread (from 2) sk_error_report()) might call tcp_poll() before tcp_done() has written sk->sk_shutdown. tcp_poll() only sees a non zero sk->sk_err and returns EPOLLERR. This patch fixes the issue by making sure to call sk_error_report() after tcp_done(). tcp_write_err() also lacks an smp_wmb(). We can reuse tcp_done_with_error() to factor out the details, as Neal suggested. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Link: https://lore.kernel.org/r/20240528125253.1966136-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03tcp: add tcp_done_with_error() helperEric Dumazet
[ Upstream commit 5e514f1cba090e1c8fff03e92a175eccfe46305f ] tcp_reset() ends with a sequence that is carefuly ordered. We need to fix [e]poll bugs in the following patches, it makes sense to use a common helper. Suggested-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Link: https://lore.kernel.org/r/20240528125253.1966136-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Stable-dep-of: 853c3bd7b791 ("tcp: fix race in tcp_write_err()") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-03net: esp: cleanup esp_output_tail_tcp() in case of unsupported ESPINTCPHagar Hemdan
[ Upstream commit 96f887a612e4cda89efc3f54bc10c1997e3ab0e9 ] xmit() functions should consume skb or return error codes in error paths. When the configuration "CONFIG_INET_ESPINTCP" is not set, the implementation of the function "esp_output_tail_tcp" violates this rule. The function frees the skb and returns the error code. This change removes the kfree_skb from both functions, for both esp4 and esp6. WARN_ON is added because esp_output_tail_tcp() should never be called if CONFIG_INET_ESPINTCP is not set. This bug was discovered and resolved using Coverity Static Analysis Security Testing (SAST) by Synopsys, Inc. Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Signed-off-by: Hagar Hemdan <hagarhem@amazon.com> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-18tcp: avoid too many retransmit packetsEric Dumazet
commit 97a9063518f198ec0adb2ecb89789de342bb8283 upstream. If a TCP socket is using TCP_USER_TIMEOUT, and the other peer retracted its window to zero, tcp_retransmit_timer() can retransmit a packet every two jiffies (2 ms for HZ=1000), for about 4 minutes after TCP_USER_TIMEOUT has 'expired'. The fix is to make sure tcp_rtx_probe0_timed_out() takes icsk->icsk_user_timeout into account. Before blamed commit, the socket would not timeout after icsk->icsk_user_timeout, but would use standard exponential backoff for the retransmits. Also worth noting that before commit e89688e3e978 ("net: tcp: fix unexcepted socket die when snd_wnd is 0"), the issue would last 2 minutes instead of 4. Fixes: b701a99e431d ("tcp: Add tcp_clamp_rto_to_user_timeout() helper to improve accuracy") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Reviewed-by: Jon Maxwell <jmaxwell37@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20240710001402.2758273-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-18tcp: use signed arithmetic in tcp_rtx_probe0_timed_out()Eric Dumazet
commit 36534d3c54537bf098224a32dc31397793d4594d upstream. Due to timer wheel implementation, a timer will usually fire after its schedule. For instance, for HZ=1000, a timeout between 512ms and 4s has a granularity of 64ms. For this range of values, the extra delay could be up to 63ms. For TCP, this means that tp->rcv_tstamp may be after inet_csk(sk)->icsk_timeout whenever the timer interrupt finally triggers, if one packet came during the extra delay. We need to make sure tcp_rtx_probe0_timed_out() handles this case. Fixes: e89688e3e978 ("net: tcp: fix unexcepted socket die when snd_wnd is 0") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Menglong Dong <imagedong@tencent.com> Acked-by: Neal Cardwell <ncardwell@google.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Link: https://lore.kernel.org/r/20240607125652.1472540-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-18udp: Set SOCK_RCU_FREE earlier in udp_lib_get_port().Kuniyuki Iwashima
[ Upstream commit 5c0b485a8c6116516f33925b9ce5b6104a6eadfd ] syzkaller triggered the warning [0] in udp_v4_early_demux(). In udp_v[46]_early_demux() and sk_lookup(), we do not touch the refcount of the looked-up sk and use sock_pfree() as skb->destructor, so we check SOCK_RCU_FREE to ensure that the sk is safe to access during the RCU grace period. Currently, SOCK_RCU_FREE is flagged for a bound socket after being put into the hash table. Moreover, the SOCK_RCU_FREE check is done too early in udp_v[46]_early_demux() and sk_lookup(), so there could be a small race window: CPU1 CPU2 ---- ---- udp_v4_early_demux() udp_lib_get_port() | |- hlist_add_head_rcu() |- sk = __udp4_lib_demux_lookup() | |- DEBUG_NET_WARN_ON_ONCE(sk_is_refcounted(sk)); `- sock_set_flag(sk, SOCK_RCU_FREE) We had the same bug in TCP and fixed it in commit 871019b22d1b ("net: set SOCK_RCU_FREE before inserting socket into hashtable"). Let's apply the same fix for UDP. [0]: WARNING: CPU: 0 PID: 11198 at net/ipv4/udp.c:2599 udp_v4_early_demux+0x481/0xb70 net/ipv4/udp.c:2599 Modules linked in: CPU: 0 PID: 11198 Comm: syz-executor.1 Not tainted 6.9.0-g93bda33046e7 #13 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:udp_v4_early_demux+0x481/0xb70 net/ipv4/udp.c:2599 Code: c5 7a 15 fe bb 01 00 00 00 44 89 e9 31 ff d3 e3 81 e3 bf ef ff ff 89 de e8 2c 74 15 fe 85 db 0f 85 02 06 00 00 e8 9f 7a 15 fe <0f> 0b e8 98 7a 15 fe 49 8d 7e 60 e8 4f 39 2f fe 49 c7 46 60 20 52 RSP: 0018:ffffc9000ce3fa58 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8318c92c RDX: ffff888036ccde00 RSI: ffffffff8318c2f1 RDI: 0000000000000001 RBP: ffff88805a2dd6e0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0001ffffffffffff R12: ffff88805a2dd680 R13: 0000000000000007 R14: ffff88800923f900 R15: ffff88805456004e FS: 00007fc449127640(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc449126e38 CR3: 000000003de4b002 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 PKRU: 55555554 Call Trace: <TASK> ip_rcv_finish_core.constprop.0+0xbdd/0xd20 net/ipv4/ip_input.c:349 ip_rcv_finish+0xda/0x150 net/ipv4/ip_input.c:447 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] ip_rcv+0x16c/0x180 net/ipv4/ip_input.c:569 __netif_receive_skb_one_core+0xb3/0xe0 net/core/dev.c:5624 __netif_receive_skb+0x21/0xd0 net/core/dev.c:5738 netif_receive_skb_internal net/core/dev.c:5824 [inline] netif_receive_skb+0x271/0x300 net/core/dev.c:5884 tun_rx_batched drivers/net/tun.c:1549 [inline] tun_get_user+0x24db/0x2c50 drivers/net/tun.c:2002 tun_chr_write_iter+0x107/0x1a0 drivers/net/tun.c:2048 new_sync_write fs/read_write.c:497 [inline] vfs_write+0x76f/0x8d0 fs/read_write.c:590 ksys_write+0xbf/0x190 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [inline] __se_sys_write fs/read_write.c:652 [inline] __x64_sys_write+0x41/0x50 fs/read_write.c:652 x64_sys_call+0xe66/0x1990 arch/x86/include/generated/asm/syscalls_64.h:2 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x4b/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7fc44a68bc1f Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 e9 cf f5 ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 3c d0 f5 ff 48 RSP: 002b:00007fc449126c90 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00000000004bc050 RCX: 00007fc44a68bc1f RDX: 0000000000000032 RSI: 00000000200000c0 RDI: 00000000000000c8 RBP: 00000000004bc050 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000032 R11: 0000000000000293 R12: 0000000000000000 R13: 000000000000000b R14: 00007fc44a5ec530 R15: 0000000000000000 </TASK> Fixes: 6acc9b432e67 ("bpf: Add helper to retrieve socket in BPF") Reported-by: syzkaller <syzkaller@googlegroups.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20240709191356.24010-1-kuniyu@amazon.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-18tcp: fix incorrect undo caused by DSACK of TLP retransmitNeal Cardwell
[ Upstream commit 0ec986ed7bab6801faed1440e8839dcc710331ff ] Loss recovery undo_retrans bookkeeping had a long-standing bug where a DSACK from a spurious TLP retransmit packet could cause an erroneous undo of a fast recovery or RTO recovery that repaired a single really-lost packet (in a sequence range outside that of the TLP retransmit). Basically, because the loss recovery state machine didn't account for the fact that it sent a TLP retransmit, the DSACK for the TLP retransmit could erroneously be implicitly be interpreted as corresponding to the normal fast recovery or RTO recovery retransmit that plugged a real hole, thus resulting in an improper undo. For example, consider the following buggy scenario where there is a real packet loss but the congestion control response is improperly undone because of this bug: + send packets P1, P2, P3, P4 + P1 is really lost + send TLP retransmit of P4 + receive SACK for original P2, P3, P4 + enter fast recovery, fast-retransmit P1, increment undo_retrans to 1 + receive DSACK for TLP P4, decrement undo_retrans to 0, undo (bug!) + receive cumulative ACK for P1-P4 (fast retransmit plugged real hole) The fix: when we initialize undo machinery in tcp_init_undo(), if there is a TLP retransmit in flight, then increment tp->undo_retrans so that we make sure that we receive a DSACK corresponding to the TLP retransmit, as well as DSACKs for all later normal retransmits, before triggering a loss recovery undo. Note that we also have to move the line that clears tp->tlp_high_seq for RTO recovery, so that upon RTO we remember the tp->tlp_high_seq value until tcp_init_undo() and clear it only afterward. Also note that the bug dates back to the original 2013 TLP implementation, commit 6ba8a3b19e76 ("tcp: Tail loss probe (TLP)"). However, this patch will only compile and work correctly with kernels that have tp->tlp_retrans, which was added only in v5.8 in 2020 in commit 76be93fc0702 ("tcp: allow at most one TLP probe per flight"). So we associate this fix with that later commit. Fixes: 76be93fc0702 ("tcp: allow at most one TLP probe per flight") Signed-off-by: Neal Cardwell <ncardwell@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Kevin Yang <yyd@google.com> Link: https://patch.msgid.link/20240703171246.1739561-1-ncardwell.sw@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-11inet_diag: Initialize pad field in struct inet_diag_req_v2Shigeru Yoshida
[ Upstream commit 61cf1c739f08190a4cbf047b9fbb192a94d87e3f ] KMSAN reported uninit-value access in raw_lookup() [1]. Diag for raw sockets uses the pad field in struct inet_diag_req_v2 for the underlying protocol. This field corresponds to the sdiag_raw_protocol field in struct inet_diag_req_raw. inet_diag_get_exact_compat() converts inet_diag_req to inet_diag_req_v2, but leaves the pad field uninitialized. So the issue occurs when raw_lookup() accesses the sdiag_raw_protocol field. Fix this by initializing the pad field in inet_diag_get_exact_compat(). Also, do the same fix in inet_diag_dump_compat() to avoid the similar issue in the future. [1] BUG: KMSAN: uninit-value in raw_lookup net/ipv4/raw_diag.c:49 [inline] BUG: KMSAN: uninit-value in raw_sock_get+0x657/0x800 net/ipv4/raw_diag.c:71 raw_lookup net/ipv4/raw_diag.c:49 [inline] raw_sock_get+0x657/0x800 net/ipv4/raw_diag.c:71 raw_diag_dump_one+0xa1/0x660 net/ipv4/raw_diag.c:99 inet_diag_cmd_exact+0x7d9/0x980 inet_diag_get_exact_compat net/ipv4/inet_diag.c:1404 [inline] inet_diag_rcv_msg_compat+0x469/0x530 net/ipv4/inet_diag.c:1426 sock_diag_rcv_msg+0x23d/0x740 net/core/sock_diag.c:282 netlink_rcv_skb+0x537/0x670 net/netlink/af_netlink.c:2564 sock_diag_rcv+0x35/0x40 net/core/sock_diag.c:297 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0xe74/0x1240 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x10c6/0x1260 net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x332/0x3d0 net/socket.c:745 ____sys_sendmsg+0x7f0/0xb70 net/socket.c:2585 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2639 __sys_sendmsg net/socket.c:2668 [inline] __do_sys_sendmsg net/socket.c:2677 [inline] __se_sys_sendmsg net/socket.c:2675 [inline] __x64_sys_sendmsg+0x27e/0x4a0 net/socket.c:2675 x64_sys_call+0x135e/0x3ce0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd9/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was stored to memory at: raw_sock_get+0x650/0x800 net/ipv4/raw_diag.c:71 raw_diag_dump_one+0xa1/0x660 net/ipv4/raw_diag.c:99 inet_diag_cmd_exact+0x7d9/0x980 inet_diag_get_exact_compat net/ipv4/inet_diag.c:1404 [inline] inet_diag_rcv_msg_compat+0x469/0x530 net/ipv4/inet_diag.c:1426 sock_diag_rcv_msg+0x23d/0x740 net/core/sock_diag.c:282 netlink_rcv_skb+0x537/0x670 net/netlink/af_netlink.c:2564 sock_diag_rcv+0x35/0x40 net/core/sock_diag.c:297 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0xe74/0x1240 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x10c6/0x1260 net/netlink/af_netlink.c:1905 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x332/0x3d0 net/socket.c:745 ____sys_sendmsg+0x7f0/0xb70 net/socket.c:2585 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2639 __sys_sendmsg net/socket.c:2668 [inline] __do_sys_sendmsg net/socket.c:2677 [inline] __se_sys_sendmsg net/socket.c:2675 [inline] __x64_sys_sendmsg+0x27e/0x4a0 net/socket.c:2675 x64_sys_call+0x135e/0x3ce0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd9/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Local variable req.i created at: inet_diag_get_exact_compat net/ipv4/inet_diag.c:1396 [inline] inet_diag_rcv_msg_compat+0x2a6/0x530 net/ipv4/inet_diag.c:1426 sock_diag_rcv_msg+0x23d/0x740 net/core/sock_diag.c:282 CPU: 1 PID: 8888 Comm: syz-executor.6 Not tainted 6.10.0-rc4-00217-g35bb670d65fc #32 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-2.fc40 04/01/2014 Fixes: 432490f9d455 ("net: ip, diag -- Add diag interface for raw sockets") Reported-by: syzkaller <syzkaller@googlegroups.com> Signed-off-by: Shigeru Yoshida <syoshida@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20240703091649.111773-1-syoshida@redhat.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-11tcp_metrics: validate source addr lengthJakub Kicinski
[ Upstream commit 66be40e622e177316ae81717aa30057ba9e61dff ] I don't see anything checking that TCP_METRICS_ATTR_SADDR_IPV4 is at least 4 bytes long, and the policy doesn't have an entry for this attribute at all (neither does it for IPv6 but v6 is manually validated). Reviewed-by: Eric Dumazet <edumazet@google.com> Fixes: 3e7013ddf55a ("tcp: metrics: Allow selective get/del of tcp-metrics based on src IP") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-11UPSTREAM: tcp: fix DSACK undo in fast recovery to call tcp_try_to_open()Neal Cardwell
[ Upstream commit a6458ab7fd4f427d4f6f54380453ad255b7fde83 ] In some production workloads we noticed that connections could sometimes close extremely prematurely with ETIMEDOUT after transmitting only 1 TLP and RTO retransmission (when we would normally expect roughly tcp_retries2 = TCP_RETR2 = 15 RTOs before a connection closes with ETIMEDOUT). From tracing we determined that these workloads can suffer from a scenario where in fast recovery, after some retransmits, a DSACK undo can happen at a point where the scoreboard is totally clear (we have retrans_out == sacked_out == lost_out == 0). In such cases, calling tcp_try_keep_open() means that we do not execute any code path that clears tp->retrans_stamp to 0. That means that tp->retrans_stamp can remain erroneously set to the start time of the undone fast recovery, even after the fast recovery is undone. If minutes or hours elapse, and then a TLP/RTO/RTO sequence occurs, then the start_ts value in retransmits_timed_out() (which is from tp->retrans_stamp) will be erroneously ancient (left over from the fast recovery undone via DSACKs). Thus this ancient tp->retrans_stamp value can cause the connection to die very prematurely with ETIMEDOUT via tcp_write_err(). The fix: we change DSACK undo in fast recovery (TCP_CA_Recovery) to call tcp_try_to_open() instead of tcp_try_keep_open(). This ensures that if no retransmits are in flight at the time of DSACK undo in fast recovery then we properly zero retrans_stamp. Note that calling tcp_try_to_open() is more consistent with other loss recovery behavior, since normal fast recovery (CA_Recovery) and RTO recovery (CA_Loss) both normally end when tp->snd_una meets or exceeds tp->high_seq and then in tcp_fastretrans_alert() the "default" switch case executes tcp_try_to_open(). Also note that by inspection this change to call tcp_try_to_open() implies at least one other nice bug fix, where now an ECE-marked DSACK that causes an undo will properly invoke tcp_enter_cwr() rather than ignoring the ECE mark. Fixes: c7d9d6a185a7 ("tcp: undo on DSACK during recovery") Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05tcp: fix tcp_rcv_fastopen_synack() to enter TCP_CA_Loss for failed TFONeal Cardwell
[ Upstream commit 5dfe9d273932c647bdc9d664f939af9a5a398cbc ] Testing determined that the recent commit 9e046bb111f1 ("tcp: clear tp->retrans_stamp in tcp_rcv_fastopen_synack()") has a race, and does not always ensure retrans_stamp is 0 after a TFO payload retransmit. If transmit completion for the SYN+data skb happens after the client TCP stack receives the SYNACK (which sometimes happens), then retrans_stamp can erroneously remain non-zero for the lifetime of the connection, causing a premature ETIMEDOUT later. Testing and tracing showed that the buggy scenario is the following somewhat tricky sequence: + Client attempts a TFO handshake. tcp_send_syn_data() sends SYN + TFO cookie + data in a single packet in the syn_data skb. It hands the syn_data skb to tcp_transmit_skb(), which makes a clone. Crucially, it then reuses the same original (non-clone) syn_data skb, transforming it by advancing the seq by one byte and removing the FIN bit, and enques the resulting payload-only skb in the sk->tcp_rtx_queue. + Client sets retrans_stamp to the start time of the three-way handshake. + Cookie mismatches or server has TFO disabled, and server only ACKs SYN. + tcp_ack() sees SYN is acked, tcp_clean_rtx_queue() clears retrans_stamp. + Since the client SYN was acked but not the payload, the TFO failure code path in tcp_rcv_fastopen_synack() tries to retransmit the payload skb. However, in some cases the transmit completion for the clone of the syn_data (which had SYN + TFO cookie + data) hasn't happened. In those cases, skb_still_in_host_queue() returns true for the retransmitted TFO payload, because the clone of the syn_data skb has not had its tx completetion. + Because skb_still_in_host_queue() finds skb_fclone_busy() is true, it sets the TSQ_THROTTLED bit and the retransmit does not happen in the tcp_rcv_fastopen_synack() call chain. + The tcp_rcv_fastopen_synack() code next implicitly assumes the retransmit process is finished, and sets retrans_stamp to 0 to clear it, but this is later overwritten (see below). + Later, upon tx completion, tcp_tsq_write() calls tcp_xmit_retransmit_queue(), which puts the retransmit in flight and sets retrans_stamp to a non-zero value. + The client receives an ACK for the retransmitted TFO payload data. + Since we're in CA_Open and there are no dupacks/SACKs/DSACKs/ECN to make tcp_ack_is_dubious() true and make us call tcp_fastretrans_alert() and reach a code path that clears retrans_stamp, retrans_stamp stays nonzero. + Later, if there is a TLP, RTO, RTO sequence, then the connection will suffer an early ETIMEDOUT due to the erroneously ancient retrans_stamp. The fix: this commit refactors the code to have tcp_rcv_fastopen_synack() retransmit by reusing the relevant parts of tcp_simple_retransmit() that enter CA_Loss (without changing cwnd) and call tcp_xmit_retransmit_queue(). We have tcp_simple_retransmit() and tcp_rcv_fastopen_synack() share code in this way because in both cases we get a packet indicating non-congestion loss (MTU reduction or TFO failure) and thus in both cases we want to retransmit as many packets as cwnd allows, without reducing cwnd. And given that retransmits will set retrans_stamp to a non-zero value (and may do so in a later calling context due to TSQ), we also want to enter CA_Loss so that we track when all retransmitted packets are ACked and clear retrans_stamp when that happens (to ensure later recurring RTOs are using the correct retrans_stamp and don't declare ETIMEDOUT prematurely). Fixes: 9e046bb111f1 ("tcp: clear tp->retrans_stamp in tcp_rcv_fastopen_synack()") Fixes: a7abf3cd76e1 ("tcp: consider using standard rtx logic in tcp_rcv_fastopen_synack()") Signed-off-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Yuchung Cheng <ycheng@google.com> Link: https://patch.msgid.link/20240624144323.2371403-1-ncardwell.sw@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-07-05Fix race for duplicate reqsk on identical SYNluoxuanqiang
[ Upstream commit ff46e3b4421923937b7f6e44ffcd3549a074f321 ] When bonding is configured in BOND_MODE_BROADCAST mode, if two identical SYN packets are received at the same time and processed on different CPUs, it can potentially create the same sk (sock) but two different reqsk (request_sock) in tcp_conn_request(). These two different reqsk will respond with two SYNACK packets, and since the generation of the seq (ISN) incorporates a timestamp, the final two SYNACK packets will have different seq values. The consequence is that when the Client receives and replies with an ACK to the earlier SYNACK packet, we will reset(RST) it. ======================================================================== This behavior is consistently reproducible in my local setup, which comprises: | NETA1 ------ NETB1 | PC_A --- bond --- | | --- bond --- PC_B | NETA2 ------ NETB2 | - PC_A is the Server and has two network cards, NETA1 and NETA2. I have bonded these two cards using BOND_MODE_BROADCAST mode and configured them to be handled by different CPU. - PC_B is the Client, also equipped with two network cards, NETB1 and NETB2, which are also bonded and configured in BOND_MODE_BROADCAST mode. If the client attempts a TCP connection to the server, it might encounter a failure. Capturing packets from the server side reveals: 10.10.10.10.45182 > localhost: Flags [S], seq 320236027, 10.10.10.10.45182 > localhost: Flags [S], seq 320236027, localhost > 10.10.10.10.45182: Flags [S.], seq 2967855116, localhost > 10.10.10.10.45182: Flags [S.], seq 2967855123, <== 10.10.10.10.45182 > localhost: Flags [.], ack 4294967290, 10.10.10.10.45182 > localhost: Flags [.], ack 4294967290, localhost > 10.10.10.10.45182: Flags [R], seq 2967855117, <== localhost > 10.10.10.10.45182: Flags [R], seq 2967855117, Two SYNACKs with different seq numbers are sent by localhost, resulting in an anomaly. ======================================================================== The attempted solution is as follows: Add a return value to inet_csk_reqsk_queue_hash_add() to confirm if the ehash insertion is successful (Up to now, the reason for unsuccessful insertion is that a reqsk for the same connection has already been inserted). If the insertion fails, release the reqsk. Due to the refcnt, Kuniyuki suggests also adding a return value check for the DCCP module; if ehash insertion fails, indicating a successful insertion of the same connection, simply release the reqsk as well. Simultaneously, In the reqsk_queue_hash_req(), the start of the req->rsk_timer is adjusted to be after successful insertion. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: luoxuanqiang <luoxuanqiang@kylinos.cn> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20240621013929.1386815-1-luoxuanqiang@kylinos.cn Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-27tcp: clear tp->retrans_stamp in tcp_rcv_fastopen_synack()Eric Dumazet
commit 9e046bb111f13461d3f9331e24e974324245140e upstream. Some applications were reporting ETIMEDOUT errors on apparently good looking flows, according to packet dumps. We were able to root cause the issue to an accidental setting of tp->retrans_stamp in the following scenario: - client sends TFO SYN with data. - server has TFO disabled, ACKs only SYN but not payload. - client receives SYNACK covering only SYN. - tcp_ack() eats SYN and sets tp->retrans_stamp to 0. - tcp_rcv_fastopen_synack() calls tcp_xmit_retransmit_queue() to retransmit TFO payload w/o SYN, sets tp->retrans_stamp to "now", but we are not in any loss recovery state. - TFO payload is ACKed. - we are not in any loss recovery state, and don't see any dupacks, so we don't get to any code path that clears tp->retrans_stamp. - tp->retrans_stamp stays non-zero for the lifetime of the connection. - after first RTO, tcp_clamp_rto_to_user_timeout() clamps second RTO to 1 jiffy due to bogus tp->retrans_stamp. - on clamped RTO with non-zero icsk_retransmits, retransmits_timed_out() sets start_ts from tp->retrans_stamp from TFO payload retransmit hours/days ago, and computes bogus long elapsed time for loss recovery, and suffers ETIMEDOUT early. Fixes: a7abf3cd76e1 ("tcp: consider using standard rtx logic in tcp_rcv_fastopen_synack()") CC: stable@vger.kernel.org Co-developed-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Co-developed-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20240614130615.396837-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-27cipso: fix total option length computationOndrej Mosnacek
[ Upstream commit 9f36169912331fa035d7b73a91252d7c2512eb1a ] As evident from the definition of ip_options_get(), the IP option IPOPT_END is used to pad the IP option data array, not IPOPT_NOP. Yet the loop that walks the IP options to determine the total IP options length in cipso_v4_delopt() doesn't take IPOPT_END into account. Fix it by recognizing the IPOPT_END value as the end of actual options. Fixes: 014ab19a69c3 ("selinux: Set socket NetLabel based on connection endpoint") Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-21tcp: count CLOSE-WAIT sockets for TCP_MIB_CURRESTABJason Xing
[ Upstream commit a46d0ea5c94205f40ecf912d1bb7806a8a64704f ] According to RFC 1213, we should also take CLOSE-WAIT sockets into consideration: "tcpCurrEstab OBJECT-TYPE ... The number of TCP connections for which the current state is either ESTABLISHED or CLOSE- WAIT." After this, CurrEstab counter will display the total number of ESTABLISHED and CLOSE-WAIT sockets. The logic of counting When we increment the counter? a) if we change the state to ESTABLISHED. b) if we change the state from SYN-RECEIVED to CLOSE-WAIT. When we decrement the counter? a) if the socket leaves ESTABLISHED and will never go into CLOSE-WAIT, say, on the client side, changing from ESTABLISHED to FIN-WAIT-1. b) if the socket leaves CLOSE-WAIT, say, on the server side, changing from CLOSE-WAIT to LAST-ACK. Please note: there are two chances that old state of socket can be changed to CLOSE-WAIT in tcp_fin(). One is SYN-RECV, the other is ESTABLISHED. So we have to take care of the former case. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Jason Xing <kernelxing@tencent.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-21net: tls: fix marking packets as decryptedJakub Kicinski
[ Upstream commit a535d59432370343058755100ee75ab03c0e3f91 ] For TLS offload we mark packets with skb->decrypted to make sure they don't escape the host without getting encrypted first. The crypto state lives in the socket, so it may get detached by a call to skb_orphan(). As a safety check - the egress path drops all packets with skb->decrypted and no "crypto-safe" socket. The skb marking was added to sendpage only (and not sendmsg), because tls_device injected data into the TCP stack using sendpage. This special case was missed when sendpage got folded into sendmsg. Fixes: c5c37af6ecad ("tcp: Convert do_tcp_sendpages() to use MSG_SPLICE_PAGES") Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20240530232607.82686-1-kuba@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-16net: fix __dst_negative_advice() raceEric Dumazet
commit 92f1655aa2b2294d0b49925f3b875a634bd3b59e upstream. __dst_negative_advice() does not enforce proper RCU rules when sk->dst_cache must be cleared, leading to possible UAF. RCU rules are that we must first clear sk->sk_dst_cache, then call dst_release(old_dst). Note that sk_dst_reset(sk) is implementing this protocol correctly, while __dst_negative_advice() uses the wrong order. Given that ip6_negative_advice() has special logic against RTF_CACHE, this means each of the three ->negative_advice() existing methods must perform the sk_dst_reset() themselves. Note the check against NULL dst is centralized in __dst_negative_advice(), there is no need to duplicate it in various callbacks. Many thanks to Clement Lecigne for tracking this issue. This old bug became visible after the blamed commit, using UDP sockets. Fixes: a87cb3e48ee8 ("net: Facility to report route quality of connected sockets") Reported-by: Clement Lecigne <clecigne@google.com> Diagnosed-by: Clement Lecigne <clecigne@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Tom Herbert <tom@herbertland.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20240528114353.1794151-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> [Lee: Stable backport] Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-06-12netfilter: tproxy: bail out if IP has been disabled on the deviceFlorian Westphal
[ Upstream commit 21a673bddc8fd4873c370caf9ae70ffc6d47e8d3 ] syzbot reports: general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] [..] RIP: 0010:nf_tproxy_laddr4+0xb7/0x340 net/ipv4/netfilter/nf_tproxy_ipv4.c:62 Call Trace: nft_tproxy_eval_v4 net/netfilter/nft_tproxy.c:56 [inline] nft_tproxy_eval+0xa9a/0x1a00 net/netfilter/nft_tproxy.c:168 __in_dev_get_rcu() can return NULL, so check for this. Reported-and-tested-by: syzbot+b94a6818504ea90d7661@syzkaller.appspotmail.com Fixes: cc6eb4338569 ("tproxy: use the interface primary IP address as a default value for --on-ip") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12net: relax socket state check at accept time.Paolo Abeni
[ Upstream commit 26afda78cda3da974fd4c287962c169e9462c495 ] Christoph reported the following splat: WARNING: CPU: 1 PID: 772 at net/ipv4/af_inet.c:761 __inet_accept+0x1f4/0x4a0 Modules linked in: CPU: 1 PID: 772 Comm: syz-executor510 Not tainted 6.9.0-rc7-g7da7119fe22b #56 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 RIP: 0010:__inet_accept+0x1f4/0x4a0 net/ipv4/af_inet.c:759 Code: 04 38 84 c0 0f 85 87 00 00 00 41 c7 04 24 03 00 00 00 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc e8 ec b7 da fd <0f> 0b e9 7f fe ff ff e8 e0 b7 da fd 0f 0b e9 fe fe ff ff 89 d9 80 RSP: 0018:ffffc90000c2fc58 EFLAGS: 00010293 RAX: ffffffff836bdd14 RBX: 0000000000000000 RCX: ffff888104668000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff836bdb89 R09: fffff52000185f64 R10: dffffc0000000000 R11: fffff52000185f64 R12: dffffc0000000000 R13: 1ffff92000185f98 R14: ffff88810754d880 R15: ffff8881007b7800 FS: 000000001c772880(0000) GS:ffff88811b280000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb9fcf2e178 CR3: 00000001045d2002 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> inet_accept+0x138/0x1d0 net/ipv4/af_inet.c:786 do_accept+0x435/0x620 net/socket.c:1929 __sys_accept4_file net/socket.c:1969 [inline] __sys_accept4+0x9b/0x110 net/socket.c:1999 __do_sys_accept net/socket.c:2016 [inline] __se_sys_accept net/socket.c:2013 [inline] __x64_sys_accept+0x7d/0x90 net/socket.c:2013 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x58/0x100 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x4315f9 Code: fd ff 48 81 c4 80 00 00 00 e9 f1 fe ff ff 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 ab b4 fd ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffdb26d9c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002b RAX: ffffffffffffffda RBX: 0000000000400300 RCX: 00000000004315f9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00000000006e1018 R08: 0000000000400300 R09: 0000000000400300 R10: 0000000000400300 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000040cdf0 R14: 000000000040ce80 R15: 0000000000000055 </TASK> The reproducer invokes shutdown() before entering the listener status. After commit 94062790aedb ("tcp: defer shutdown(SEND_SHUTDOWN) for TCP_SYN_RECV sockets"), the above causes the child to reach the accept syscall in FIN_WAIT1 status. Eric noted we can relax the existing assertion in __inet_accept() Reported-by: Christoph Paasch <cpaasch@apple.com> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/490 Suggested-by: Eric Dumazet <edumazet@google.com> Fixes: 94062790aedb ("tcp: defer shutdown(SEND_SHUTDOWN) for TCP_SYN_RECV sockets") Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/23ab880a44d8cfd967e84de8b93dbf48848e3d8c.1716299669.git.pabeni@redhat.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12tcp: Fix shift-out-of-bounds in dctcp_update_alpha().Kuniyuki Iwashima
[ Upstream commit 3ebc46ca8675de6378e3f8f40768e180bb8afa66 ] In dctcp_update_alpha(), we use a module parameter dctcp_shift_g as follows: alpha -= min_not_zero(alpha, alpha >> dctcp_shift_g); ... delivered_ce <<= (10 - dctcp_shift_g); It seems syzkaller started fuzzing module parameters and triggered shift-out-of-bounds [0] by setting 100 to dctcp_shift_g: memcpy((void*)0x20000080, "/sys/module/tcp_dctcp/parameters/dctcp_shift_g\000", 47); res = syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0x20000080ul, /*flags=*/2ul, /*mode=*/0ul); memcpy((void*)0x20000000, "100\000", 4); syscall(__NR_write, /*fd=*/r[0], /*val=*/0x20000000ul, /*len=*/4ul); Let's limit the max value of dctcp_shift_g by param_set_uint_minmax(). With this patch: # echo 10 > /sys/module/tcp_dctcp/parameters/dctcp_shift_g # cat /sys/module/tcp_dctcp/parameters/dctcp_shift_g 10 # echo 11 > /sys/module/tcp_dctcp/parameters/dctcp_shift_g -bash: echo: write error: Invalid argument [0]: UBSAN: shift-out-of-bounds in net/ipv4/tcp_dctcp.c:143:12 shift exponent 100 is too large for 32-bit type 'u32' (aka 'unsigned int') CPU: 0 PID: 8083 Comm: syz-executor345 Not tainted 6.9.0-05151-g1b294a1f3561 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x201/0x300 lib/dump_stack.c:114 ubsan_epilogue lib/ubsan.c:231 [inline] __ubsan_handle_shift_out_of_bounds+0x346/0x3a0 lib/ubsan.c:468 dctcp_update_alpha+0x540/0x570 net/ipv4/tcp_dctcp.c:143 tcp_in_ack_event net/ipv4/tcp_input.c:3802 [inline] tcp_ack+0x17b1/0x3bc0 net/ipv4/tcp_input.c:3948 tcp_rcv_state_process+0x57a/0x2290 net/ipv4/tcp_input.c:6711 tcp_v4_do_rcv+0x764/0xc40 net/ipv4/tcp_ipv4.c:1937 sk_backlog_rcv include/net/sock.h:1106 [inline] __release_sock+0x20f/0x350 net/core/sock.c:2983 release_sock+0x61/0x1f0 net/core/sock.c:3549 mptcp_subflow_shutdown+0x3d0/0x620 net/mptcp/protocol.c:2907 mptcp_check_send_data_fin+0x225/0x410 net/mptcp/protocol.c:2976 __mptcp_close+0x238/0xad0 net/mptcp/protocol.c:3072 mptcp_close+0x2a/0x1a0 net/mptcp/protocol.c:3127 inet_release+0x190/0x1f0 net/ipv4/af_inet.c:437 __sock_release net/socket.c:659 [inline] sock_close+0xc0/0x240 net/socket.c:1421 __fput+0x41b/0x890 fs/file_table.c:422 task_work_run+0x23b/0x300 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x9c8/0x2540 kernel/exit.c:878 do_group_exit+0x201/0x2b0 kernel/exit.c:1027 __do_sys_exit_group kernel/exit.c:1038 [inline] __se_sys_exit_group kernel/exit.c:1036 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1036 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xe4/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x67/0x6f RIP: 0033:0x7f6c2b5005b6 Code: Unable to access opcode bytes at 0x7f6c2b50058c. RSP: 002b:00007ffe883eb948 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f6c2b5862f0 RCX: 00007f6c2b5005b6 RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001 RBP: 0000000000000001 R08: 00000000000000e7 R09: ffffffffffffffc0 R10: 0000000000000006 R11: 0000000000000246 R12: 00007f6c2b5862f0 R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001 </TASK> Reported-by: syzkaller <syzkaller@googlegroups.com> Reported-by: Yue Sun <samsun1006219@gmail.com> Reported-by: xingwei lee <xrivendell7@gmail.com> Closes: https://lore.kernel.org/netdev/CAEkJfYNJM=cw-8x7_Vmj1J6uYVCWMbbvD=EFmDPVBGpTsqOxEA@mail.gmail.com/ Fixes: e3118e8359bb ("net: tcp: add DCTCP congestion control algorithm") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://lore.kernel.org/r/20240517091626.32772-1-kuniyu@amazon.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12tcp: avoid premature drops in tcp_add_backlog()Eric Dumazet
[ Upstream commit ec00ed472bdb7d0af840da68c8c11bff9f4d9caa ] While testing TCP performance with latest trees, I saw suspect SOCKET_BACKLOG drops. tcp_add_backlog() computes its limit with : limit = (u32)READ_ONCE(sk->sk_rcvbuf) + (u32)(READ_ONCE(sk->sk_sndbuf) >> 1); limit += 64 * 1024; This does not take into account that sk->sk_backlog.len is reset only at the very end of __release_sock(). Both sk->sk_backlog.len and sk->sk_rmem_alloc could reach sk_rcvbuf in normal conditions. We should double sk->sk_rcvbuf contribution in the formula to absorb bubbles in the backlog, which happen more often for very fast flows. This change maintains decent protection against abuses. Fixes: c377411f2494 ("net: sk_add_backlog() take rmem_alloc into account") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20240423125620.3309458-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12udp: Avoid call to compute_score on multiple sitesGabriel Krisman Bertazi
[ Upstream commit 50aee97d15113b95a68848db1f0cb2a6c09f753a ] We've observed a 7-12% performance regression in iperf3 UDP ipv4 and ipv6 tests with multiple sockets on Zen3 cpus, which we traced back to commit f0ea27e7bfe1 ("udp: re-score reuseport groups when connected sockets are present"). The failing tests were those that would spawn UDP sockets per-cpu on systems that have a high number of cpus. Unsurprisingly, it is not caused by the extra re-scoring of the reused socket, but due to the compiler no longer inlining compute_score, once it has the extra call site in udp4_lib_lookup2. This is augmented by the "Safe RET" mitigation for SRSO, needed in our Zen3 cpus. We could just explicitly inline it, but compute_score() is quite a large function, around 300b. Inlining in two sites would almost double udp4_lib_lookup2, which is a silly thing to do just to workaround a mitigation. Instead, this patch shuffles the code a bit to avoid the multiple calls to compute_score. Since it is a static function used in one spot, the compiler can safely fold it in, as it did before, without increasing the text size. With this patch applied I ran my original iperf3 testcases. The failing cases all looked like this (ipv4): iperf3 -c 127.0.0.1 --udp -4 -f K -b $R -l 8920 -t 30 -i 5 -P 64 -O 2 where $R is either 1G/10G/0 (max, unlimited). I ran 3 times each. baseline is v6.9-rc3. harmean == harmonic mean; CV == coefficient of variation. ipv4: 1G 10G MAX HARMEAN (CV) HARMEAN (CV) HARMEAN (CV) baseline 1743852.66(0.0208) 1725933.02(0.0167) 1705203.78(0.0386) patched 1968727.61(0.0035) 1962283.22(0.0195) 1923853.50(0.0256) ipv6: 1G 10G MAX HARMEAN (CV) HARMEAN (CV) HARMEAN (CV) baseline 1729020.03(0.0028) 1691704.49(0.0243) 1692251.34(0.0083) patched 1900422.19(0.0067) 1900968.01(0.0067) 1568532.72(0.1519) This restores the performance we had before the change above with this benchmark. We obviously don't expect any real impact when mitigations are disabled, but just to be sure it also doesn't regresses: mitigations=off ipv4: 1G 10G MAX HARMEAN (CV) HARMEAN (CV) HARMEAN (CV) baseline 3230279.97(0.0066) 3229320.91(0.0060) 2605693.19(0.0697) patched 3242802.36(0.0073) 3239310.71(0.0035) 2502427.19(0.0882) Cc: Lorenz Bauer <lmb@isovalent.com> Fixes: f0ea27e7bfe1 ("udp: re-score reuseport groups when connected sockets are present") Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-17tcp: Use refcount_inc_not_zero() in tcp_twsk_unique().Kuniyuki Iwashima
[ Upstream commit f2db7230f73a80dbb179deab78f88a7947f0ab7e ] Anderson Nascimento reported a use-after-free splat in tcp_twsk_unique() with nice analysis. Since commit ec94c2696f0b ("tcp/dccp: avoid one atomic operation for timewait hashdance"), inet_twsk_hashdance() sets TIME-WAIT socket's sk_refcnt after putting it into ehash and releasing the bucket lock. Thus, there is a small race window where other threads could try to reuse the port during connect() and call sock_hold() in tcp_twsk_unique() for the TIME-WAIT socket with zero refcnt. If that happens, the refcnt taken by tcp_twsk_unique() is overwritten and sock_put() will cause underflow, triggering a real use-after-free somewhere else. To avoid the use-after-free, we need to use refcount_inc_not_zero() in tcp_twsk_unique() and give up on reusing the port if it returns false. [0]: refcount_t: addition on 0; use-after-free. WARNING: CPU: 0 PID: 1039313 at lib/refcount.c:25 refcount_warn_saturate+0xe5/0x110 CPU: 0 PID: 1039313 Comm: trigger Not tainted 6.8.6-200.fc39.x86_64 #1 Hardware name: VMware, Inc. VMware20,1/440BX Desktop Reference Platform, BIOS VMW201.00V.21805430.B64.2305221830 05/22/2023 RIP: 0010:refcount_warn_saturate+0xe5/0x110 Code: 42 8e ff 0f 0b c3 cc cc cc cc 80 3d aa 13 ea 01 00 0f 85 5e ff ff ff 48 c7 c7 f8 8e b7 82 c6 05 96 13 ea 01 01 e8 7b 42 8e ff <0f> 0b c3 cc cc cc cc 48 c7 c7 50 8f b7 82 c6 05 7a 13 ea 01 01 e8 RSP: 0018:ffffc90006b43b60 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff888009bb3ef0 RCX: 0000000000000027 RDX: ffff88807be218c8 RSI: 0000000000000001 RDI: ffff88807be218c0 RBP: 0000000000069d70 R08: 0000000000000000 R09: ffffc90006b439f0 R10: ffffc90006b439e8 R11: 0000000000000003 R12: ffff8880029ede84 R13: 0000000000004e20 R14: ffffffff84356dc0 R15: ffff888009bb3ef0 FS: 00007f62c10926c0(0000) GS:ffff88807be00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020ccb000 CR3: 000000004628c005 CR4: 0000000000f70ef0 PKRU: 55555554 Call Trace: <TASK> ? refcount_warn_saturate+0xe5/0x110 ? __warn+0x81/0x130 ? refcount_warn_saturate+0xe5/0x110 ? report_bug+0x171/0x1a0 ? refcount_warn_saturate+0xe5/0x110 ? handle_bug+0x3c/0x80 ? exc_invalid_op+0x17/0x70 ? asm_exc_invalid_op+0x1a/0x20 ? refcount_warn_saturate+0xe5/0x110 tcp_twsk_unique+0x186/0x190 __inet_check_established+0x176/0x2d0 __inet_hash_connect+0x74/0x7d0 ? __pfx___inet_check_established+0x10/0x10 tcp_v4_connect+0x278/0x530 __inet_stream_connect+0x10f/0x3d0 inet_stream_connect+0x3a/0x60 __sys_connect+0xa8/0xd0 __x64_sys_connect+0x18/0x20 do_syscall_64+0x83/0x170 entry_SYSCALL_64_after_hwframe+0x78/0x80 RIP: 0033:0x7f62c11a885d Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a3 45 0c 00 f7 d8 64 89 01 48 RSP: 002b:00007f62c1091e58 EFLAGS: 00000296 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 0000000020ccb004 RCX: 00007f62c11a885d RDX: 0000000000000010 RSI: 0000000020ccb000 RDI: 0000000000000003 RBP: 00007f62c1091e90 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 00007f62c10926c0 R13: ffffffffffffff88 R14: 0000000000000000 R15: 00007ffe237885b0 </TASK> Fixes: ec94c2696f0b ("tcp/dccp: avoid one atomic operation for timewait hashdance") Reported-by: Anderson Nascimento <anderson@allelesecurity.com> Closes: https://lore.kernel.org/netdev/37a477a6-d39e-486b-9577-3463f655a6b7@allelesecurity.com/ Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20240501213145.62261-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-17tcp: defer shutdown(SEND_SHUTDOWN) for TCP_SYN_RECV socketsEric Dumazet
[ Upstream commit 94062790aedb505bdda209b10bea47b294d6394f ] TCP_SYN_RECV state is really special, it is only used by cross-syn connections, mostly used by fuzzers. In the following crash [1], syzbot managed to trigger a divide by zero in tcp_rcv_space_adjust() A socket makes the following state transitions, without ever calling tcp_init_transfer(), meaning tcp_init_buffer_space() is also not called. TCP_CLOSE connect() TCP_SYN_SENT TCP_SYN_RECV shutdown() -> tcp_shutdown(sk, SEND_SHUTDOWN) TCP_FIN_WAIT1 To fix this issue, change tcp_shutdown() to not perform a TCP_SYN_RECV -> TCP_FIN_WAIT1 transition, which makes no sense anyway. When tcp_rcv_state_process() later changes socket state from TCP_SYN_RECV to TCP_ESTABLISH, then look at sk->sk_shutdown to finally enter TCP_FIN_WAIT1 state, and send a FIN packet from a sane socket state. This means tcp_send_fin() can now be called from BH context, and must use GFP_ATOMIC allocations. [1] divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 1 PID: 5084 Comm: syz-executor358 Not tainted 6.9.0-rc6-syzkaller-00022-g98369dccd2f8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:tcp_rcv_space_adjust+0x2df/0x890 net/ipv4/tcp_input.c:767 Code: e3 04 4c 01 eb 48 8b 44 24 38 0f b6 04 10 84 c0 49 89 d5 0f 85 a5 03 00 00 41 8b 8e c8 09 00 00 89 e8 29 c8 48 0f af c3 31 d2 <48> f7 f1 48 8d 1c 43 49 8d 96 76 08 00 00 48 89 d0 48 c1 e8 03 48 RSP: 0018:ffffc900031ef3f0 EFLAGS: 00010246 RAX: 0c677a10441f8f42 RBX: 000000004fb95e7e RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000027d4b11f R08: ffffffff89e535a4 R09: 1ffffffff25e6ab7 R10: dffffc0000000000 R11: ffffffff8135e920 R12: ffff88802a9f8d30 R13: dffffc0000000000 R14: ffff88802a9f8d00 R15: 1ffff1100553f2da FS: 00005555775c0380(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1155bf2304 CR3: 000000002b9f2000 CR4: 0000000000350ef0 Call Trace: <TASK> tcp_recvmsg_locked+0x106d/0x25a0 net/ipv4/tcp.c:2513 tcp_recvmsg+0x25d/0x920 net/ipv4/tcp.c:2578 inet6_recvmsg+0x16a/0x730 net/ipv6/af_inet6.c:680 sock_recvmsg_nosec net/socket.c:1046 [inline] sock_recvmsg+0x109/0x280 net/socket.c:1068 ____sys_recvmsg+0x1db/0x470 net/socket.c:2803 ___sys_recvmsg net/socket.c:2845 [inline] do_recvmmsg+0x474/0xae0 net/socket.c:2939 __sys_recvmmsg net/socket.c:3018 [inline] __do_sys_recvmmsg net/socket.c:3041 [inline] __se_sys_recvmmsg net/socket.c:3034 [inline] __x64_sys_recvmmsg+0x199/0x250 net/socket.c:3034 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faeb6363db9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffcc1997168 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007faeb6363db9 RDX: 0000000000000001 RSI: 0000000020000bc0 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000001c R10: 0000000000000122 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000001 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Link: https://lore.kernel.org/r/20240501125448.896529-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-17xfrm: Preserve vlan tags for transport mode software GROPaul Davey
[ Upstream commit 58fbfecab965014b6e3cc956a76b4a96265a1add ] The software GRO path for esp transport mode uses skb_mac_header_rebuild prior to re-injecting the packet via the xfrm_napi_dev. This only copies skb->mac_len bytes of header which may not be sufficient if the packet contains 802.1Q tags or other VLAN tags. Worse copying only the initial header will leave a packet marked as being VLAN tagged but without the corresponding tag leading to mangling when it is later untagged. The VLAN tags are important when receiving the decrypted esp transport mode packet after GRO processing to ensure it is received on the correct interface. Therefore record the full mac header length in xfrm*_transport_input for later use in corresponding xfrm*_transport_finish to copy the entire mac header when rebuilding the mac header for GRO. The skb->data pointer is left pointing skb->mac_header bytes after the start of the mac header as is expected by the network stack and network and transport header offsets reset to this location. Fixes: 7785bba299a8 ("esp: Add a software GRO codepath") Signed-off-by: Paul Davey <paul.davey@alliedtelesis.co.nz> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-17net: gro: add flush check in udp_gro_receive_segmentRichard Gobert
[ Upstream commit 5babae777c61aa8a8679d59d3cdc54165ad96d42 ] GRO-GSO path is supposed to be transparent and as such L3 flush checks are relevant to all UDP flows merging in GRO. This patch uses the same logic and code from tcp_gro_receive, terminating merge if flush is non zero. Fixes: e20cf8d3f1f7 ("udp: implement GRO for plain UDP sockets.") Signed-off-by: Richard Gobert <richardbgobert@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>