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3 daysxfrm: Set transport header to fix UDP GRO handlingTobias Brunner
[ Upstream commit 3ac9e29211fa2df5539ba0d742c8fe9fe95fdc79 ] The referenced commit replaced a call to __xfrm4|6_udp_encap_rcv() with a custom check for non-ESP markers. But what the called function also did was setting the transport header to the ESP header. The function that follows, esp4|6_gro_receive(), relies on that being set when it calls xfrm_parse_spi(). We have to set the full offset as the skb's head was not moved yet so adding just the UDP header length won't work. Fixes: e3fd05777685 ("xfrm: Fix UDP GRO handling for some corner cases") Signed-off-by: Tobias Brunner <tobias@strongswan.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
11 daysnet: fix segmentation after TCP/UDP fraglist GROFelix Fietkau
[ Upstream commit 9f735b6f8a77d7be7f8b0765dc93587774832cb1 ] Since "net: gro: use cb instead of skb->network_header", the skb network header is no longer set in the GRO path. This breaks fraglist segmentation, which relies on ip_hdr()/tcp_hdr() to check for address/port changes. Fix this regression by selectively setting the network header for merged segment skbs. Fixes: 186b1ea73ad8 ("net: gro: use cb instead of skb->network_header") Signed-off-by: Felix Fietkau <nbd@nbd.name> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250705150622.10699-1-nbd@nbd.name Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-17tcp: Correct signedness in skb remaining space calculationJiayuan Chen
[ Upstream commit d3a5f2871adc0c61c61869f37f3e697d97f03d8c ] Syzkaller reported a bug [1] where sk->sk_forward_alloc can overflow. When we send data, if an skb exists at the tail of the write queue, the kernel will attempt to append the new data to that skb. However, the code that checks for available space in the skb is flawed: ''' copy = size_goal - skb->len ''' The types of the variables involved are: ''' copy: ssize_t (s64 on 64-bit systems) size_goal: int skb->len: unsigned int ''' Due to C's type promotion rules, the signed size_goal is converted to an unsigned int to match skb->len before the subtraction. The result is an unsigned int. When this unsigned int result is then assigned to the s64 copy variable, it is zero-extended, preserving its non-negative value. Consequently, copy is always >= 0. Assume we are sending 2GB of data and size_goal has been adjusted to a value smaller than skb->len. The subtraction will result in copy holding a very large positive integer. In the subsequent logic, this large value is used to update sk->sk_forward_alloc, which can easily cause it to overflow. The syzkaller reproducer uses TCP_REPAIR to reliably create this condition. However, this can also occur in real-world scenarios. The tcp_bound_to_half_wnd() function can also reduce size_goal to a small value. This would cause the subsequent tcp_wmem_schedule() to set sk->sk_forward_alloc to a value close to INT_MAX. Further memory allocation requests would then cause sk_forward_alloc to wrap around and become negative. [1]: https://syzkaller.appspot.com/bug?extid=de6565462ab540f50e47 Reported-by: syzbot+de6565462ab540f50e47@syzkaller.appspotmail.com Fixes: 270a1c3de47e ("tcp: Support MSG_SPLICE_PAGES") Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20250707054112.101081-1-jiayuan.chen@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-27tcp: fix passive TFO socket having invalid NAPI IDDavid Wei
[ Upstream commit dbe0ca8da1f62b6252e7be6337209f4d86d4a914 ] There is a bug with passive TFO sockets returning an invalid NAPI ID 0 from SO_INCOMING_NAPI_ID. Normally this is not an issue, but zero copy receive relies on a correct NAPI ID to process sockets on the right queue. Fix by adding a sk_mark_napi_id_set(). Fixes: e5907459ce7e ("tcp: Record Rx hash and NAPI ID in tcp_child_process") Signed-off-by: David Wei <dw@davidwei.uk> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250617212102.175711-5-dw@davidwei.uk Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-27tcp: fix tcp_packet_delayed() for tcp_is_non_sack_preventing_reopen() behaviorNeal Cardwell
[ Upstream commit d0fa59897e049e84432600e86df82aab3dce7aa5 ] After the following commit from 2024: commit e37ab7373696 ("tcp: fix to allow timestamp undo if no retransmits were sent") ...there was buggy behavior where TCP connections without SACK support could easily see erroneous undo events at the end of fast recovery or RTO recovery episodes. The erroneous undo events could cause those connections to suffer repeated loss recovery episodes and high retransmit rates. The problem was an interaction between the non-SACK behavior on these connections and the undo logic. The problem is that, for non-SACK connections at the end of a loss recovery episode, if snd_una == high_seq, then tcp_is_non_sack_preventing_reopen() holds steady in CA_Recovery or CA_Loss, but clears tp->retrans_stamp to 0. Then upon the next ACK the "tcp: fix to allow timestamp undo if no retransmits were sent" logic saw the tp->retrans_stamp at 0 and erroneously concluded that no data was retransmitted, and erroneously performed an undo of the cwnd reduction, restoring cwnd immediately to the value it had before loss recovery. This caused an immediate burst of traffic and build-up of queues and likely another immediate loss recovery episode. This commit fixes tcp_packet_delayed() to ignore zero retrans_stamp values for non-SACK connections when snd_una is at or above high_seq, because tcp_is_non_sack_preventing_reopen() clears retrans_stamp in this case, so it's not a valid signal that we can undo. Note that the commit named in the Fixes footer restored long-present behavior from roughly 2005-2019, so apparently this bug was present for a while during that era, and this was simply not caught. Fixes: e37ab7373696 ("tcp: fix to allow timestamp undo if no retransmits were sent") Reported-by: Eric Wheeler <netdev@lists.ewheeler.net> Closes: https://lore.kernel.org/netdev/64ea9333-e7f9-0df-b0f2-8d566143acab@ewheeler.net/ Signed-off-by: Neal Cardwell <ncardwell@google.com> Co-developed-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.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>
2025-06-27ipv4/route: Use this_cpu_inc() for stats on PREEMPT_RTSebastian Andrzej Siewior
[ Upstream commit 1c0829788a6e6e165846b9bedd0b908ef16260b6 ] The statistics are incremented with raw_cpu_inc() assuming it always happens with bottom half disabled. Without per-CPU locking in local_bh_disable() on PREEMPT_RT this is no longer true. Use this_cpu_inc() on PREEMPT_RT for the increment to not worry about preemption. Cc: David Ahern <dsahern@kernel.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: https://patch.msgid.link/20250512092736.229935-4-bigeasy@linutronix.de Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-27tcp: add receive queue awareness in tcp_rcv_space_adjust()Eric Dumazet
[ Upstream commit ea33537d82921e71f852ea2ed985acc562125efe ] If the application can not drain fast enough a TCP socket queue, tcp_rcv_space_adjust() can overestimate tp->rcvq_space.space. Then sk->sk_rcvbuf can grow and hit tcp_rmem[2] for no good reason. Fix this by taking into acount the number of available bytes. Keeping sk->sk_rcvbuf at the right size allows better cache efficiency. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Wei Wang <weiwan@google.com> Link: https://patch.msgid.link/20250513193919.1089692-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-27tcp: fix initial tp->rcvq_space.space value for passive TS enabled flowsEric Dumazet
[ Upstream commit cd171461b90a2d2cf230943df60d580174633718 ] tcp_rcv_state_process() must tweak tp->advmss for TS enabled flows before the call to tcp_init_transfer() / tcp_init_buffer_space(). Otherwise tp->rcvq_space.space is off by 120 bytes (TCP_INIT_CWND * TCPOLEN_TSTAMP_ALIGNED). Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Wei Wang <weiwan@google.com> Link: https://patch.msgid.link/20250513193919.1089692-7-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-27tcp: remove zero TCP TS samples for autotuningEric Dumazet
[ Upstream commit d59fc95be9d0fd05ed3ccc11b4a2f832bdf2ee03 ] For TCP flows using ms RFC 7323 timestamp granularity tcp_rcv_rtt_update() can be fed with 1 ms samples, breaking TCP autotuning for data center flows with sub ms RTT. Instead, rely on the window based samples, fed by tcp_rcv_rtt_measure() tcp_rcvbuf_grow() for a 10 second TCP_STREAM sesssion now looks saner. We can see rcvbuf is kept at a reasonable value. 222.234976: tcp:tcp_rcvbuf_grow: time=348 rtt_us=330 copied=110592 inq=0 space=40960 ooo=0 scaling_ratio=230 rcvbuf=131072 ... 222.235276: tcp:tcp_rcvbuf_grow: time=300 rtt_us=288 copied=126976 inq=0 space=110592 ooo=0 scaling_ratio=230 rcvbuf=246187 ... 222.235569: tcp:tcp_rcvbuf_grow: time=294 rtt_us=288 copied=184320 inq=0 space=126976 ooo=0 scaling_ratio=230 rcvbuf=282659 ... 222.235833: tcp:tcp_rcvbuf_grow: time=264 rtt_us=244 copied=373760 inq=0 space=184320 ooo=0 scaling_ratio=230 rcvbuf=410312 ... 222.236142: tcp:tcp_rcvbuf_grow: time=308 rtt_us=219 copied=424960 inq=20480 space=373760 ooo=0 scaling_ratio=230 rcvbuf=832022 ... 222.236378: tcp:tcp_rcvbuf_grow: time=236 rtt_us=219 copied=692224 inq=49152 space=404480 ooo=0 scaling_ratio=230 rcvbuf=900407 ... 222.236602: tcp:tcp_rcvbuf_grow: time=225 rtt_us=219 copied=730112 inq=49152 space=643072 ooo=0 scaling_ratio=230 rcvbuf=1431534 ... 222.237050: tcp:tcp_rcvbuf_grow: time=229 rtt_us=219 copied=1160192 inq=49152 space=680960 ooo=0 scaling_ratio=230 rcvbuf=1515876 ... 222.237618: tcp:tcp_rcvbuf_grow: time=305 rtt_us=218 copied=2228224 inq=49152 space=1111040 ooo=0 scaling_ratio=230 rcvbuf=2473271 ... 222.238591: tcp:tcp_rcvbuf_grow: time=224 rtt_us=218 copied=3063808 inq=360448 space=2179072 ooo=0 scaling_ratio=230 rcvbuf=4850803 ... 222.240647: tcp:tcp_rcvbuf_grow: time=260 rtt_us=218 copied=2752512 inq=0 space=2703360 ooo=0 scaling_ratio=230 rcvbuf=6017914 ... 222.243535: tcp:tcp_rcvbuf_grow: time=224 rtt_us=218 copied=2834432 inq=49152 space=2752512 ooo=0 scaling_ratio=230 rcvbuf=6127331 ... 222.245108: tcp:tcp_rcvbuf_grow: time=240 rtt_us=218 copied=2883584 inq=49152 space=2785280 ooo=0 scaling_ratio=230 rcvbuf=6200275 ... 222.245333: tcp:tcp_rcvbuf_grow: time=224 rtt_us=218 copied=2859008 inq=0 space=2834432 ooo=0 scaling_ratio=230 rcvbuf=6309692 ... 222.301021: tcp:tcp_rcvbuf_grow: time=222 rtt_us=218 copied=2883584 inq=0 space=2859008 ooo=0 scaling_ratio=230 rcvbuf=6364400 ... 222.989242: tcp:tcp_rcvbuf_grow: time=225 rtt_us=218 copied=2899968 inq=0 space=2883584 ooo=0 scaling_ratio=230 rcvbuf=6419108 ... 224.139553: tcp:tcp_rcvbuf_grow: time=224 rtt_us=218 copied=3014656 inq=65536 space=2899968 ooo=0 scaling_ratio=230 rcvbuf=6455580 ... 224.584608: tcp:tcp_rcvbuf_grow: time=232 rtt_us=218 copied=3014656 inq=49152 space=2949120 ooo=0 scaling_ratio=230 rcvbuf=6564997 ... 230.145560: tcp:tcp_rcvbuf_grow: time=223 rtt_us=218 copied=2981888 inq=0 space=2965504 ooo=0 scaling_ratio=230 rcvbuf=6601469 ... Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Wei Wang <weiwan@google.com> Link: https://patch.msgid.link/20250513193919.1089692-6-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-27tcp: always seek for minimal rtt in tcp_rcv_rtt_update()Eric Dumazet
[ Upstream commit b879dcb1aeeca278eacaac0b1e2425b1c7599f9f ] tcp_rcv_rtt_update() goal is to maintain an estimation of the RTT in tp->rcv_rtt_est.rtt_us, used by tcp_rcv_space_adjust() When TCP TS are enabled, tcp_rcv_rtt_update() is using EWMA to smooth the samples. Change this to immediately latch the incoming value if it is lower than tp->rcv_rtt_est.rtt_us, so that tcp_rcv_space_adjust() does not overshoot tp->rcvq_space.space and sk->sk_rcvbuf. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250513193919.1089692-8-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-06-19net: fix udp gso skb_segment after pull from frag_listShiming Cheng
[ Upstream commit 3382a1ed7f778db841063f5d7e317ac55f9e7f72 ] Commit a1e40ac5b5e9 ("net: gso: fix udp gso fraglist segmentation after pull from frag_list") detected invalid geometry in frag_list skbs and redirects them from skb_segment_list to more robust skb_segment. But some packets with modified geometry can also hit bugs in that code. We don't know how many such cases exist. Addressing each one by one also requires touching the complex skb_segment code, which risks introducing bugs for other types of skbs. Instead, linearize all these packets that fail the basic invariants on gso fraglist skbs. That is more robust. If only part of the fraglist payload is pulled into head_skb, it will always cause exception when splitting skbs by skb_segment. For detailed call stack information, see below. Valid SKB_GSO_FRAGLIST skbs - consist of two or more segments - the head_skb holds the protocol headers plus first gso_size - one or more frag_list skbs hold exactly one segment - all but the last must be gso_size Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can modify fraglist skbs, breaking these invariants. In extreme cases they pull one part of data into skb linear. For UDP, this causes three payloads with lengths of (11,11,10) bytes were pulled tail to become (12,10,10) bytes. The skbs no longer meets the above SKB_GSO_FRAGLIST conditions because payload was pulled into head_skb, it needs to be linearized before pass to regular skb_segment. skb_segment+0xcd0/0xd14 __udp_gso_segment+0x334/0x5f4 udp4_ufo_fragment+0x118/0x15c inet_gso_segment+0x164/0x338 skb_mac_gso_segment+0xc4/0x13c __skb_gso_segment+0xc4/0x124 validate_xmit_skb+0x9c/0x2c0 validate_xmit_skb_list+0x4c/0x80 sch_direct_xmit+0x70/0x404 __dev_queue_xmit+0x64c/0xe5c neigh_resolve_output+0x178/0x1c4 ip_finish_output2+0x37c/0x47c __ip_finish_output+0x194/0x240 ip_finish_output+0x20/0xf4 ip_output+0x100/0x1a0 NF_HOOK+0xc4/0x16c ip_forward+0x314/0x32c ip_rcv+0x90/0x118 __netif_receive_skb+0x74/0x124 process_backlog+0xe8/0x1a4 __napi_poll+0x5c/0x1f8 net_rx_action+0x154/0x314 handle_softirqs+0x154/0x4b8 [118.376811] [C201134] rxq0_pus: [name:bug&]kernel BUG at net/core/skbuff.c:4278! [118.376829] [C201134] rxq0_pus: [name:traps&]Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP [118.470774] [C201134] rxq0_pus: [name:mrdump&]Kernel Offset: 0x178cc00000 from 0xffffffc008000000 [118.470810] [C201134] rxq0_pus: [name:mrdump&]PHYS_OFFSET: 0x40000000 [118.470827] [C201134] rxq0_pus: [name:mrdump&]pstate: 60400005 (nZCv daif +PAN -UAO) [118.470848] [C201134] rxq0_pus: [name:mrdump&]pc : [0xffffffd79598aefc] skb_segment+0xcd0/0xd14 [118.470900] [C201134] rxq0_pus: [name:mrdump&]lr : [0xffffffd79598a5e8] skb_segment+0x3bc/0xd14 [118.470928] [C201134] rxq0_pus: [name:mrdump&]sp : ffffffc008013770 Fixes: a1e40ac5b5e9 ("gso: fix udp gso fraglist segmentation after pull from frag_list") Signed-off-by: Shiming Cheng <shiming.cheng@mediatek.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>
2025-06-19netfilter: nf_tables: nft_fib: consistent l3mdev handlingFlorian Westphal
[ Upstream commit 9a119669fb1924cd9658c16da39a5a585e129e50 ] fib has two modes: 1. Obtain output device according to source or destination address 2. Obtain the type of the address, e.g. local, unicast, multicast. 'fib daddr type' should return 'local' if the address is configured in this netns or unicast otherwise. 'fib daddr . iif type' should return 'local' if the address is configured on the input interface or unicast otherwise, i.e. more restrictive. However, if the interface is part of a VRF, then 'fib daddr type' returns unicast even if the address is configured on the incoming interface. This is broken for both ipv4 and ipv6. In the ipv4 case, inet_dev_addr_type must only be used if the 'iif' or 'oif' (strict mode) was requested. Else inet_addr_type_dev_table() needs to be used and the correct dev argument must be passed as well so the correct fib (vrf) table is used. In the ipv6 case, the bug is similar, without strict mode, dev is NULL so .flowi6_l3mdev will be set to 0. Add a new 'nft_fib_l3mdev_master_ifindex_rcu()' helper and use that to init the .l3mdev structure member. For ipv6, use it from nft_fib6_flowi_init() which gets called from both the 'type' and the 'route' mode eval functions. This provides consistent behaviour for all modes for both ipv4 and ipv6: If strict matching is requested, the input respectively output device of the netfilter hooks is used. Otherwise, use skb->dev to obtain the l3mdev ifindex. Without this, most type checks in updated nft_fib.sh selftest fail: FAIL: did not find veth0 . 10.9.9.1 . local in fibtype4 FAIL: did not find veth0 . dead:1::1 . local in fibtype6 FAIL: did not find veth0 . dead:9::1 . local in fibtype6 FAIL: did not find tvrf . 10.0.1.1 . local in fibtype4 FAIL: did not find tvrf . 10.9.9.1 . local in fibtype4 FAIL: did not find tvrf . dead:1::1 . local in fibtype6 FAIL: did not find tvrf . dead:9::1 . local in fibtype6 FAIL: fib expression address types match (iif in vrf) (fib errounously returns 'unicast' for all of them, even though all of these addresses are local to the vrf). Fixes: f6d0cbcf09c5 ("netfilter: nf_tables: add fib expression") 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>
2025-05-29xfrm: Fix UDP GRO handling for some corner casesTobias Brunner
[ Upstream commit e3fd0577768584ece824c8b661c40fb3d912812a ] This fixes an issue that's caused if there is a mismatch between the data offset in the GRO header and the length fields in the regular sk_buff due to the pskb_pull()/skb_push() calls. That's because the UDP GRO layer stripped off the UDP header via skb_gro_pull() already while the UDP header was explicitly not pulled/pushed in this function. For example, an IKE packet that triggered this had len=data_len=1268 and the data_offset in the GRO header was 28 (IPv4 + UDP). So pskb_pull() was called with an offset of 28-8=20, which reduced len to 1248 and via pskb_may_pull() and __pskb_pull_tail() it also set data_len to 1248. As the ESP offload module was not loaded, the function bailed out and called skb_push(), which restored len to 1268, however, data_len remained at 1248. So while skb_headlen() was 0 before, it was now 20. The latter caused a difference of 8 instead of 28 (or 0 if pskb_pull()/skb_push() was called with the complete GRO data_offset) in gro_try_pull_from_frag0() that triggered a call to gro_pull_from_frag0() that corrupted the packet. This change uses a more GRO-like approach seen in other GRO receivers via skb_gro_header() to just read the actual data we are interested in and does not try to "restore" the UDP header at this point to call the existing function. If the offload module is not loaded, it immediately bails out, otherwise, it only does a quick check to see if the packet is an IKE or keepalive packet instead of calling the existing function. Fixes: 172bf009c18d ("xfrm: Support GRO for IPv4 ESP in UDP encapsulation") Fixes: 221ddb723d90 ("xfrm: Support GRO for IPv6 ESP in UDP encapsulation") Signed-off-by: Tobias Brunner <tobias@strongswan.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-29espintcp: remove encap socket caching to avoid reference leakSabrina Dubroca
[ Upstream commit 028363685bd0b7a19b4a820f82dd905b1dc83999 ] The current scheme for caching the encap socket can lead to reference leaks when we try to delete the netns. The reference chain is: xfrm_state -> enacp_sk -> netns Since the encap socket is a userspace socket, it holds a reference on the netns. If we delete the espintcp state (through flush or individual delete) before removing the netns, the reference on the socket is dropped and the netns is correctly deleted. Otherwise, the netns may not be reachable anymore (if all processes within the ns have terminated), so we cannot delete the xfrm state to drop its reference on the socket. This patch results in a small (~2% in my tests) performance regression. A GC-type mechanism could be added for the socket cache, to clear references if the state hasn't been used "recently", but it's a lot more complex than just not caching the socket. Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-29espintcp: fix skb leaksSabrina Dubroca
[ Upstream commit 63c1f19a3be3169e51a5812d22a6d0c879414076 ] A few error paths are missing a kfree_skb. Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-29ipv4: ip_gre: Fix set but not used warning in ipgre_err() if IPv4-onlyGeert Uytterhoeven
[ Upstream commit 50f37fc2a39c4a8cc4813629b4cf239b71c6097d ] if CONFIG_NET_IPGRE is enabled, but CONFIG_IPV6 is disabled: net/ipv4/ip_gre.c: In function ‘ipgre_err’: net/ipv4/ip_gre.c:144:22: error: variable ‘data_len’ set but not used [-Werror=unused-but-set-variable] 144 | unsigned int data_len = 0; | ^~~~~~~~ Fix this by moving all data_len processing inside the IPV6-only section that uses its result. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202501121007.2GofXmh5-lkp@intel.com/ Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/d09113cfe2bfaca02f3dddf832fb5f48dd20958b.1738704881.git.geert@linux-m68k.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-29ip: fib_rules: Fetch net from fib_rule in fib[46]_rule_configure().Kuniyuki Iwashima
[ Upstream commit 5a1ccffd30a08f5a2428cd5fbb3ab03e8eb6c66d ] The following patch will not set skb->sk from VRF path. Let's fetch net from fib_rule->fr_net instead of sock_net(skb->sk) in fib[46]_rule_configure(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Tested-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20250207072502.87775-5-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-29ipv4: fib: Move fib_valid_key_len() to rtm_to_fib_config().Kuniyuki Iwashima
[ Upstream commit 254ba7e6032d3fc738050d500b0c1d8197af90ca ] fib_valid_key_len() is called in the beginning of fib_table_insert() or fib_table_delete() to check if the prefix length is valid. fib_table_insert() and fib_table_delete() are called from 3 paths - ip_rt_ioctl() - inet_rtm_newroute() / inet_rtm_delroute() - fib_magic() In the first ioctl() path, rtentry_to_fib_config() checks the prefix length with bad_mask(). Also, fib_magic() always passes the correct prefix: 32 or ifa->ifa_prefixlen, which is already validated. Let's move fib_valid_key_len() to the rtnetlink path, rtm_to_fib_config(). While at it, 2 direct returns in rtm_to_fib_config() are changed to goto to match other places in the same function Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250228042328.96624-12-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-29tcp: bring back NUMA dispersion in inet_ehash_locks_alloc()Eric Dumazet
[ Upstream commit f8ece40786c9342249aa0a1b55e148ee23b2a746 ] We have platforms with 6 NUMA nodes and 480 cpus. inet_ehash_locks_alloc() currently allocates a single 64KB page to hold all ehash spinlocks. This adds more pressure on a single node. Change inet_ehash_locks_alloc() to use vmalloc() to spread the spinlocks on all online nodes, driven by NUMA policies. At boot time, NUMA policy is interleave=all, meaning that tcp_hashinfo.ehash_locks gets hash dispersion on all nodes. Tested: lack5:~# grep inet_ehash_locks_alloc /proc/vmallocinfo 0x00000000d9aec4d1-0x00000000a828b652 69632 inet_ehash_locks_alloc+0x90/0x100 pages=16 vmalloc N0=2 N1=3 N2=3 N3=3 N4=3 N5=2 lack5:~# echo 8192 >/proc/sys/net/ipv4/tcp_child_ehash_entries lack5:~# numactl --interleave=all unshare -n bash -c "grep inet_ehash_locks_alloc /proc/vmallocinfo" 0x000000004e99d30c-0x00000000763f3279 36864 inet_ehash_locks_alloc+0x90/0x100 pages=8 vmalloc N0=1 N1=2 N2=2 N3=1 N4=1 N5=1 0x00000000d9aec4d1-0x00000000a828b652 69632 inet_ehash_locks_alloc+0x90/0x100 pages=16 vmalloc N0=2 N1=3 N2=3 N3=3 N4=3 N5=2 lack5:~# numactl --interleave=0,5 unshare -n bash -c "grep inet_ehash_locks_alloc /proc/vmallocinfo" 0x00000000fd73a33e-0x0000000004b9a177 36864 inet_ehash_locks_alloc+0x90/0x100 pages=8 vmalloc N0=4 N5=4 0x00000000d9aec4d1-0x00000000a828b652 69632 inet_ehash_locks_alloc+0x90/0x100 pages=16 vmalloc N0=2 N1=3 N2=3 N3=3 N4=3 N5=2 lack5:~# echo 1024 >/proc/sys/net/ipv4/tcp_child_ehash_entries lack5:~# numactl --interleave=all unshare -n bash -c "grep inet_ehash_locks_alloc /proc/vmallocinfo" 0x00000000db07d7a2-0x00000000ad697d29 8192 inet_ehash_locks_alloc+0x90/0x100 pages=1 vmalloc N2=1 0x00000000d9aec4d1-0x00000000a828b652 69632 inet_ehash_locks_alloc+0x90/0x100 pages=16 vmalloc N0=2 N1=3 N2=3 N3=3 N4=3 N5=2 Signed-off-by: Eric Dumazet <edumazet@google.com> Tested-by: Jason Xing <kerneljasonxing@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250305130550.1865988-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-29tcp: reorganize tcp_in_ack_event() and tcp_count_delivered()Ilpo Järvinen
[ Upstream commit 149dfb31615e22271d2525f078c95ea49bc4db24 ] - Move tcp_count_delivered() earlier and split tcp_count_delivered_ce() out of it - Move tcp_in_ack_event() later - While at it, remove the inline from tcp_in_ack_event() and let the compiler to decide Accurate ECN's heuristics does not know if there is going to be ACE field based CE counter increase or not until after rtx queue has been processed. Only then the number of ACKed bytes/pkts is available. As CE or not affects presence of FLAG_ECE, that information for tcp_in_ack_event is not yet available in the old location of the call to tcp_in_ack_event(). Signed-off-by: Ilpo Järvinen <ij@kernel.org> Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-09net: use sock_gen_put() when sk_state is TCP_TIME_WAITJibin Zhang
[ Upstream commit f920436a44295ca791ebb6dae3f4190142eec703 ] It is possible for a pointer of type struct inet_timewait_sock to be returned from the functions __inet_lookup_established() and __inet6_lookup_established(). This can cause a crash when the returned pointer is of type struct inet_timewait_sock and sock_put() is called on it. The following is a crash call stack that shows sk->sk_wmem_alloc being accessed in sk_free() during the call to sock_put() on a struct inet_timewait_sock pointer. To avoid this issue, use sock_gen_put() instead of sock_put() when sk->sk_state is TCP_TIME_WAIT. mrdump.ko ipanic() + 120 vmlinux notifier_call_chain(nr_to_call=-1, nr_calls=0) + 132 vmlinux atomic_notifier_call_chain(val=0) + 56 vmlinux panic() + 344 vmlinux add_taint() + 164 vmlinux end_report() + 136 vmlinux kasan_report(size=0) + 236 vmlinux report_tag_fault() + 16 vmlinux do_tag_recovery() + 16 vmlinux __do_kernel_fault() + 88 vmlinux do_bad_area() + 28 vmlinux do_tag_check_fault() + 60 vmlinux do_mem_abort() + 80 vmlinux el1_abort() + 56 vmlinux el1h_64_sync_handler() + 124 vmlinux > 0xFFFFFFC080011294() vmlinux __lse_atomic_fetch_add_release(v=0xF2FFFF82A896087C) vmlinux __lse_atomic_fetch_sub_release(v=0xF2FFFF82A896087C) vmlinux arch_atomic_fetch_sub_release(i=1, v=0xF2FFFF82A896087C) + 8 vmlinux raw_atomic_fetch_sub_release(i=1, v=0xF2FFFF82A896087C) + 8 vmlinux atomic_fetch_sub_release(i=1, v=0xF2FFFF82A896087C) + 8 vmlinux __refcount_sub_and_test(i=1, r=0xF2FFFF82A896087C, oldp=0) + 8 vmlinux __refcount_dec_and_test(r=0xF2FFFF82A896087C, oldp=0) + 8 vmlinux refcount_dec_and_test(r=0xF2FFFF82A896087C) + 8 vmlinux sk_free(sk=0xF2FFFF82A8960700) + 28 vmlinux sock_put() + 48 vmlinux tcp6_check_fraglist_gro() + 236 vmlinux tcp6_gro_receive() + 624 vmlinux ipv6_gro_receive() + 912 vmlinux dev_gro_receive() + 1116 vmlinux napi_gro_receive() + 196 ccmni.ko ccmni_rx_callback() + 208 ccmni.ko ccmni_queue_recv_skb() + 388 ccci_dpmaif.ko dpmaif_rxq_push_thread() + 1088 vmlinux kthread() + 268 vmlinux 0xFFFFFFC08001F30C() Fixes: c9d1d23e5239 ("net: add heuristic for enabling TCP fraglist GRO") Signed-off-by: Jibin Zhang <jibin.zhang@mediatek.com> Signed-off-by: Shiming Cheng <shiming.cheng@mediatek.com> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Link: https://patch.msgid.link/20250429020412.14163-1-shiming.cheng@mediatek.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-09net: ipv6: fix UDPv6 GSO segmentation with NATFelix Fietkau
[ Upstream commit b936a9b8d4a585ccb6d454921c36286bfe63e01d ] If any address or port is changed, update it in all packets and recalculate checksum. Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") Signed-off-by: Felix Fietkau <nbd@nbd.name> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250426153210.14044-1-nbd@nbd.name Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-02netfilter: fib: avoid lookup if socket is availableFlorian Westphal
commit eaaff9b6702e99be5d79135f2afa9fc48a0d59e0 upstream. In case the fib match is used from the input hook we can avoid the fib lookup if early demux assigned a socket for us: check that the input interface matches sk-cached one. Rework the existing 'lo bypass' logic to first check sk, then for loopback interface type to elide the fib lookup. This speeds up fib matching a little, before: 93.08 GBit/s (no rules at all) 75.1 GBit/s ("fib saddr . iif oif missing drop" in prerouting) 75.62 GBit/s ("fib saddr . iif oif missing drop" in input) After: 92.48 GBit/s (no rules at all) 75.62 GBit/s (fib rule in prerouting) 90.37 GBit/s (fib rule in input). Numbers for the 'no rules' and 'prerouting' are expected to closely match in-between runs, the 3rd/input test case exercises the the 'avoid lookup if cached ifindex in sk matches' case. Test used iperf3 via veth interface, lo can't be used due to existing loopback test. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-04-10net: fix geneve_opt length integer overflowLin Ma
[ Upstream commit b27055a08ad4b415dcf15b63034f9cb236f7fb40 ] struct geneve_opt uses 5 bit length for each single option, which means every vary size option should be smaller than 128 bytes. However, all current related Netlink policies cannot promise this length condition and the attacker can exploit a exact 128-byte size option to *fake* a zero length option and confuse the parsing logic, further achieve heap out-of-bounds read. One example crash log is like below: [ 3.905425] ================================================================== [ 3.905925] BUG: KASAN: slab-out-of-bounds in nla_put+0xa9/0xe0 [ 3.906255] Read of size 124 at addr ffff888005f291cc by task poc/177 [ 3.906646] [ 3.906775] CPU: 0 PID: 177 Comm: poc-oob-read Not tainted 6.1.132 #1 [ 3.907131] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 [ 3.907784] Call Trace: [ 3.907925] <TASK> [ 3.908048] dump_stack_lvl+0x44/0x5c [ 3.908258] print_report+0x184/0x4be [ 3.909151] kasan_report+0xc5/0x100 [ 3.909539] kasan_check_range+0xf3/0x1a0 [ 3.909794] memcpy+0x1f/0x60 [ 3.909968] nla_put+0xa9/0xe0 [ 3.910147] tunnel_key_dump+0x945/0xba0 [ 3.911536] tcf_action_dump_1+0x1c1/0x340 [ 3.912436] tcf_action_dump+0x101/0x180 [ 3.912689] tcf_exts_dump+0x164/0x1e0 [ 3.912905] fw_dump+0x18b/0x2d0 [ 3.913483] tcf_fill_node+0x2ee/0x460 [ 3.914778] tfilter_notify+0xf4/0x180 [ 3.915208] tc_new_tfilter+0xd51/0x10d0 [ 3.918615] rtnetlink_rcv_msg+0x4a2/0x560 [ 3.919118] netlink_rcv_skb+0xcd/0x200 [ 3.919787] netlink_unicast+0x395/0x530 [ 3.921032] netlink_sendmsg+0x3d0/0x6d0 [ 3.921987] __sock_sendmsg+0x99/0xa0 [ 3.922220] __sys_sendto+0x1b7/0x240 [ 3.922682] __x64_sys_sendto+0x72/0x90 [ 3.922906] do_syscall_64+0x5e/0x90 [ 3.923814] entry_SYSCALL_64_after_hwframe+0x6e/0xd8 [ 3.924122] RIP: 0033:0x7e83eab84407 [ 3.924331] Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 faf [ 3.925330] RSP: 002b:00007ffff505e370 EFLAGS: 00000202 ORIG_RAX: 000000000000002c [ 3.925752] RAX: ffffffffffffffda RBX: 00007e83eaafa740 RCX: 00007e83eab84407 [ 3.926173] RDX: 00000000000001a8 RSI: 00007ffff505e3c0 RDI: 0000000000000003 [ 3.926587] RBP: 00007ffff505f460 R08: 00007e83eace1000 R09: 000000000000000c [ 3.926977] R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffff505f3c0 [ 3.927367] R13: 00007ffff505f5c8 R14: 00007e83ead1b000 R15: 00005d4fbbe6dcb8 Fix these issues by enforing correct length condition in related policies. Fixes: 925d844696d9 ("netfilter: nft_tunnel: add support for geneve opts") Fixes: 4ece47787077 ("lwtunnel: add options setting and dumping for geneve") Fixes: 0ed5269f9e41 ("net/sched: add tunnel option support to act_tunnel_key") Fixes: 0a6e77784f49 ("net/sched: allow flower to match tunnel options") Signed-off-by: Lin Ma <linma@zju.edu.cn> Reviewed-by: Xin Long <lucien.xin@gmail.com> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Link: https://patch.msgid.link/20250402165632.6958-1-linma@zju.edu.cn Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10tunnels: Accept PACKET_HOST in skb_tunnel_check_pmtu().Guillaume Nault
[ Upstream commit 8930424777e43257f5bf6f0f0f53defd0d30415c ] Because skb_tunnel_check_pmtu() doesn't handle PACKET_HOST packets, commit 30a92c9e3d6b ("openvswitch: Set the skbuff pkt_type for proper pmtud support.") forced skb->pkt_type to PACKET_OUTGOING for openvswitch packets that are sent using the OVS_ACTION_ATTR_OUTPUT action. This allowed such packets to invoke the iptunnel_pmtud_check_icmp() or iptunnel_pmtud_check_icmpv6() helpers and thus trigger PMTU update on the input device. However, this also broke other parts of PMTU discovery. Since these packets don't have the PACKET_HOST type anymore, they won't trigger the sending of ICMP Fragmentation Needed or Packet Too Big messages to remote hosts when oversized (see the skb_in->pkt_type condition in __icmp_send() for example). These two skb->pkt_type checks are therefore incompatible as one requires skb->pkt_type to be PACKET_HOST, while the other requires it to be anything but PACKET_HOST. It makes sense to not trigger ICMP messages for non-PACKET_HOST packets as these messages should be generated only for incoming l2-unicast packets. However there doesn't seem to be any reason for skb_tunnel_check_pmtu() to ignore PACKET_HOST packets. Allow both cases to work by allowing skb_tunnel_check_pmtu() to work on PACKET_HOST packets and not overriding skb->pkt_type in openvswitch anymore. Fixes: 30a92c9e3d6b ("openvswitch: Set the skbuff pkt_type for proper pmtud support.") Fixes: 4cb47a8644cc ("tunnels: PMTU discovery support for directly bridged IP packets") Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Reviewed-by: Aaron Conole <aconole@redhat.com> Tested-by: Aaron Conole <aconole@redhat.com> Link: https://patch.msgid.link/eac941652b86fddf8909df9b3bf0d97bc9444793.1743208264.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10udp: Fix memory accounting leak.Kuniyuki Iwashima
[ Upstream commit df207de9d9e7a4d92f8567e2c539d9c8c12fd99d ] Matt Dowling reported a weird UDP memory usage issue. Under normal operation, the UDP memory usage reported in /proc/net/sockstat remains close to zero. However, it occasionally spiked to 524,288 pages and never dropped. Moreover, the value doubled when the application was terminated. Finally, it caused intermittent packet drops. We can reproduce the issue with the script below [0]: 1. /proc/net/sockstat reports 0 pages # cat /proc/net/sockstat | grep UDP: UDP: inuse 1 mem 0 2. Run the script till the report reaches 524,288 # python3 test.py & sleep 5 # cat /proc/net/sockstat | grep UDP: UDP: inuse 3 mem 524288 <-- (INT_MAX + 1) >> PAGE_SHIFT 3. Kill the socket and confirm the number never drops # pkill python3 && sleep 5 # cat /proc/net/sockstat | grep UDP: UDP: inuse 1 mem 524288 4. (necessary since v6.0) Trigger proto_memory_pcpu_drain() # python3 test.py & sleep 1 && pkill python3 5. The number doubles # cat /proc/net/sockstat | grep UDP: UDP: inuse 1 mem 1048577 The application set INT_MAX to SO_RCVBUF, which triggered an integer overflow in udp_rmem_release(). When a socket is close()d, udp_destruct_common() purges its receive queue and sums up skb->truesize in the queue. This total is calculated and stored in a local unsigned integer variable. The total size is then passed to udp_rmem_release() to adjust memory accounting. However, because the function takes a signed integer argument, the total size can wrap around, causing an overflow. Then, the released amount is calculated as follows: 1) Add size to sk->sk_forward_alloc. 2) Round down sk->sk_forward_alloc to the nearest lower multiple of PAGE_SIZE and assign it to amount. 3) Subtract amount from sk->sk_forward_alloc. 4) Pass amount >> PAGE_SHIFT to __sk_mem_reduce_allocated(). When the issue occurred, the total in udp_destruct_common() was 2147484480 (INT_MAX + 833), which was cast to -2147482816 in udp_rmem_release(). At 1) sk->sk_forward_alloc is changed from 3264 to -2147479552, and 2) sets -2147479552 to amount. 3) reverts the wraparound, so we don't see a warning in inet_sock_destruct(). However, udp_memory_allocated ends up doubling at 4). Since commit 3cd3399dd7a8 ("net: implement per-cpu reserves for memory_allocated"), memory usage no longer doubles immediately after a socket is close()d because __sk_mem_reduce_allocated() caches the amount in udp_memory_per_cpu_fw_alloc. However, the next time a UDP socket receives a packet, the subtraction takes effect, causing UDP memory usage to double. This issue makes further memory allocation fail once the socket's sk->sk_rmem_alloc exceeds net.ipv4.udp_rmem_min, resulting in packet drops. To prevent this issue, let's use unsigned int for the calculation and call sk_forward_alloc_add() only once for the small delta. Note that first_packet_length() also potentially has the same problem. [0]: from socket import * SO_RCVBUFFORCE = 33 INT_MAX = (2 ** 31) - 1 s = socket(AF_INET, SOCK_DGRAM) s.bind(('', 0)) s.setsockopt(SOL_SOCKET, SO_RCVBUFFORCE, INT_MAX) c = socket(AF_INET, SOCK_DGRAM) c.connect(s.getsockname()) data = b'a' * 100 while True: c.send(data) Fixes: f970bd9e3a06 ("udp: implement memory accounting helpers") Reported-by: Matt Dowling <madowlin@amazon.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250401184501.67377-3-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10udp: Fix multiple wraparounds of sk->sk_rmem_alloc.Kuniyuki Iwashima
[ Upstream commit 5a465a0da13ee9fbd7d3cd0b2893309b0fe4b7e3 ] __udp_enqueue_schedule_skb() has the following condition: if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf) goto drop; sk->sk_rcvbuf is initialised by net.core.rmem_default and later can be configured by SO_RCVBUF, which is limited by net.core.rmem_max, or SO_RCVBUFFORCE. If we set INT_MAX to sk->sk_rcvbuf, the condition is always false as sk->sk_rmem_alloc is also signed int. Then, the size of the incoming skb is added to sk->sk_rmem_alloc unconditionally. This results in integer overflow (possibly multiple times) on sk->sk_rmem_alloc and allows a single socket to have skb up to net.core.udp_mem[1]. For example, if we set a large value to udp_mem[1] and INT_MAX to sk->sk_rcvbuf and flood packets to the socket, we can see multiple overflows: # cat /proc/net/sockstat | grep UDP: UDP: inuse 3 mem 7956736 <-- (7956736 << 12) bytes > INT_MAX * 15 ^- PAGE_SHIFT # ss -uam State Recv-Q ... UNCONN -1757018048 ... <-- flipping the sign repeatedly skmem:(r2537949248,rb2147483646,t0,tb212992,f1984,w0,o0,bl0,d0) Previously, we had a boundary check for INT_MAX, which was removed by commit 6a1f12dd85a8 ("udp: relax atomic operation on sk->sk_rmem_alloc"). A complete fix would be to revert it and cap the right operand by INT_MAX: rmem = atomic_add_return(size, &sk->sk_rmem_alloc); if (rmem > min(size + (unsigned int)sk->sk_rcvbuf, INT_MAX)) goto uncharge_drop; but we do not want to add the expensive atomic_add_return() back just for the corner case. Casting rmem to unsigned int prevents multiple wraparounds, but we still allow a single wraparound. # cat /proc/net/sockstat | grep UDP: UDP: inuse 3 mem 524288 <-- (INT_MAX + 1) >> 12 # ss -uam State Recv-Q ... UNCONN -2147482816 ... <-- INT_MAX + 831 bytes skmem:(r2147484480,rb2147483646,t0,tb212992,f3264,w0,o0,bl0,d14468947) So, let's define rmem and rcvbuf as unsigned int and check skb->truesize only when rcvbuf is large enough to lower the overflow possibility. Note that we still have a small chance to see overflow if multiple skbs to the same socket are processed on different core at the same time and each size does not exceed the limit but the total size does. Note also that we must ignore skb->truesize for a small buffer as explained in commit 363dc73acacb ("udp: be less conservative with sock rmem accounting"). Fixes: 6a1f12dd85a8 ("udp: relax atomic operation on sk->sk_rmem_alloc") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250401184501.67377-2-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-03-13net-timestamp: support TCP GSO case for a few missing flagsJason Xing
[ Upstream commit 3c9231ea6497dfc50ac0ef69fff484da27d0df66 ] When I read through the TSO codes, I found out that we probably miss initializing the tx_flags of last seg when TSO is turned off, which means at the following points no more timestamp (for this last one) will be generated. There are three flags to be handled in this patch: 1. SKBTX_HW_TSTAMP 2. SKBTX_BPF 3. SKBTX_SCHED_TSTAMP Note that SKBTX_BPF[1] was added in 6.14.0-rc2 by commit 6b98ec7e882af ("bpf: Add BPF_SOCK_OPS_TSTAMP_SCHED_CB callback") and only belongs to net-next branch material for now. The common issue of the above three flags can be fixed by this single patch. This patch initializes the tx_flags to SKBTX_ANY_TSTAMP like what the UDP GSO does to make the newly segmented last skb inherit the tx_flags so that requested timestamp will be generated in each certain layer, or else that last one has zero value of tx_flags which leads to no timestamp at all. Fixes: 4ed2d765dfacc ("net-timestamp: TCP timestamping") Signed-off-by: Jason Xing <kerneljasonxing@gmail.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>
2025-03-13net: gso: fix ownership in __udp_gso_segmentAntoine Tenart
[ Upstream commit ee01b2f2d7d0010787c2343463965bbc283a497f ] In __udp_gso_segment the skb destructor is removed before segmenting the skb but the socket reference is kept as-is. This is an issue if the original skb is later orphaned as we can hit the following bug: kernel BUG at ./include/linux/skbuff.h:3312! (skb_orphan) RIP: 0010:ip_rcv_core+0x8b2/0xca0 Call Trace: ip_rcv+0xab/0x6e0 __netif_receive_skb_one_core+0x168/0x1b0 process_backlog+0x384/0x1100 __napi_poll.constprop.0+0xa1/0x370 net_rx_action+0x925/0xe50 The above can happen following a sequence of events when using OpenVSwitch, when an OVS_ACTION_ATTR_USERSPACE action precedes an OVS_ACTION_ATTR_OUTPUT action: 1. OVS_ACTION_ATTR_USERSPACE is handled (in do_execute_actions): the skb goes through queue_gso_packets and then __udp_gso_segment, where its destructor is removed. 2. The segments' data are copied and sent to userspace. 3. OVS_ACTION_ATTR_OUTPUT is handled (in do_execute_actions) and the same original skb is sent to its path. 4. If it later hits skb_orphan, we hit the bug. Fix this by also removing the reference to the socket in __udp_gso_segment. Fixes: ad405857b174 ("udp: better wmem accounting on gso") Signed-off-by: Antoine Tenart <atenart@kernel.org> Link: https://patch.msgid.link/20250226171352.258045-1-atenart@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-03-07tcp: Defer ts_recent changes until req is ownedWang Hai
[ Upstream commit 8d52da23b6c68a0f6bad83959ebb61a2cf623c4e ] Recently a bug was discovered where the server had entered TCP_ESTABLISHED state, but the upper layers were not notified. The same 5-tuple packet may be processed by different CPUSs, so two CPUs may receive different ack packets at the same time when the state is TCP_NEW_SYN_RECV. In that case, req->ts_recent in tcp_check_req may be changed concurrently, which will probably cause the newsk's ts_recent to be incorrectly large. So that tcp_validate_incoming will fail. At this point, newsk will not be able to enter the TCP_ESTABLISHED. cpu1 cpu2 tcp_check_req tcp_check_req req->ts_recent = rcv_tsval = t1 req->ts_recent = rcv_tsval = t2 syn_recv_sock tcp_sk(child)->rx_opt.ts_recent = req->ts_recent = t2 // t1 < t2 tcp_child_process tcp_rcv_state_process tcp_validate_incoming tcp_paws_check if ((s32)(rx_opt->ts_recent - rx_opt->rcv_tsval) <= paws_win) // t2 - t1 > paws_win, failed tcp_v4_do_rcv tcp_rcv_state_process // TCP_ESTABLISHED The cpu2's skb or a newly received skb will call tcp_v4_do_rcv to get the newsk into the TCP_ESTABLISHED state, but at this point it is no longer possible to notify the upper layer application. A notification mechanism could be added here, but the fix is more complex, so the current fix is used. In tcp_check_req, req->ts_recent is used to assign a value to tcp_sk(child)->rx_opt.ts_recent, so removing the change in req->ts_recent and changing tcp_sk(child)->rx_opt.ts_recent directly after owning the req fixes this bug. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Wang Hai <wanghai38@huawei.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-03-07tcp: devmem: don't write truncated dmabuf CMSGs to userspaceStanislav Fomichev
[ Upstream commit 18912c520674ec4d920fe3826e7e4fefeecdf5ae ] Currently, we report -ETOOSMALL (err) only on the first iteration (!sent). When we get put_cmsg error after a bunch of successful put_cmsg calls, we don't signal the error at all. This might be confusing on the userspace side which will see truncated CMSGs but no MSG_CTRUNC signal. Consider the following case: - sizeof(struct cmsghdr) = 16 - sizeof(struct dmabuf_cmsg) = 24 - total cmsg size (CMSG_LEN) = 40 (16+24) When calling recvmsg with msg_controllen=60, the userspace will receive two(!) dmabuf_cmsg(s), the first one will be a valid one and the second one will be silently truncated. There is no easy way to discover the truncation besides doing something like "cm->cmsg_len != CMSG_LEN(sizeof(dmabuf_cmsg))". Introduce new put_devmem_cmsg wrapper that reports an error instead of doing the truncation. Mina suggests that it's the intended way this API should work. Note that we might now report MSG_CTRUNC when the users (incorrectly) call us with msg_control == NULL. Fixes: 8f0b3cc9a4c1 ("tcp: RX path for devmem TCP") Reviewed-by: Mina Almasry <almasrymina@google.com> Signed-off-by: Stanislav Fomichev <sdf@fomichev.me> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250224174401.3582695-1-sdf@fomichev.me Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-03-07ipv4: Convert ip_route_input() to dscp_t.Guillaume Nault
[ Upstream commit 7e863e5db6185b1add0df4cb01b31a4ed1c4b738 ] Pass a dscp_t variable to ip_route_input(), instead of a plain u8, to prevent accidental setting of ECN bits in ->flowi4_tos. Callers of ip_route_input() to consider are: * input_action_end_dx4_finish() and input_action_end_dt4() in net/ipv6/seg6_local.c. These functions set the tos parameter to 0, which is already a valid dscp_t value, so they don't need to be adjusted for the new prototype. * icmp_route_lookup(), which already has a dscp_t variable to pass as parameter. We just need to remove the inet_dscp_to_dsfield() conversion. * br_nf_pre_routing_finish(), ip_options_rcv_srr() and ip4ip6_err(), which get the DSCP directly from IPv4 headers. Define a helper to read the .tos field of struct iphdr as dscp_t, so that these function don't have to do the conversion manually. While there, declare *iph as const in br_nf_pre_routing_finish(), declare its local variables in reverse-christmas-tree order and move the "err = ip_route_input()" assignment out of the conditional to avoid checkpatch warning. Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/e9d40781d64d3d69f4c79ac8a008b8d67a033e8d.1727807926.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Stable-dep-of: 27843ce6ba3d ("ipvlan: ensure network headers are in skb linear part") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-03-07ipv4: Convert icmp_route_lookup() to dscp_t.Guillaume Nault
[ Upstream commit 913c83a610bb7dd8e5952a2b4663e1feec0b5de6 ] Pass a dscp_t variable to icmp_route_lookup(), instead of a plain u8, to prevent accidental setting of ECN bits in ->flowi4_tos. Rename that variable ("tos" -> "dscp") to make the intent clear. While there, reorganise the function parameters to fill up horizontal space. Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/294fead85c6035bcdc5fcf9a6bb4ce8798c45ba1.1727807926.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Stable-dep-of: 27843ce6ba3d ("ipvlan: ensure network headers are in skb linear part") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-27bpf: Fix wrong copied_seq calculationJiayuan Chen
[ Upstream commit 36b62df5683c315ba58c950f1a9c771c796c30ec ] 'sk->copied_seq' was updated in the tcp_eat_skb() function when the action of a BPF program was SK_REDIRECT. For other actions, like SK_PASS, the update logic for 'sk->copied_seq' was moved to tcp_bpf_recvmsg_parser() to ensure the accuracy of the 'fionread' feature. It works for a single stream_verdict scenario, as it also modified sk_data_ready->sk_psock_verdict_data_ready->tcp_read_skb to remove updating 'sk->copied_seq'. However, for programs where both stream_parser and stream_verdict are active (strparser purpose), tcp_read_sock() was used instead of tcp_read_skb() (sk_data_ready->strp_data_ready->tcp_read_sock). tcp_read_sock() now still updates 'sk->copied_seq', leading to duplicate updates. In summary, for strparser + SK_PASS, copied_seq is redundantly calculated in both tcp_read_sock() and tcp_bpf_recvmsg_parser(). The issue causes incorrect copied_seq calculations, which prevent correct data reads from the recv() interface in user-land. We do not want to add new proto_ops to implement a new version of tcp_read_sock, as this would introduce code complexity [1]. We could have added noack and copied_seq to desc, and then called ops->read_sock. However, unfortunately, other modules didn’t fully initialize desc to zero. So, for now, we are directly calling tcp_read_sock_noack() in tcp_bpf.c. [1]: https://lore.kernel.org/bpf/20241218053408.437295-1-mrpre@163.com Fixes: e5c6de5fa025 ("bpf, sockmap: Incorrectly handling copied_seq") Suggested-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Jiayuan Chen <mrpre@163.com> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://patch.msgid.link/20250122100917.49845-3-mrpre@163.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-27tcp: drop secpath at the same time as we currently drop dstSabrina Dubroca
[ Upstream commit 9b6412e6979f6f9e0632075f8f008937b5cd4efd ] Xiumei reported hitting the WARN in xfrm6_tunnel_net_exit while running tests that boil down to: - create a pair of netns - run a basic TCP test over ipcomp6 - delete the pair of netns The xfrm_state found on spi_byaddr was not deleted at the time we delete the netns, because we still have a reference on it. This lingering reference comes from a secpath (which holds a ref on the xfrm_state), which is still attached to an skb. This skb is not leaked, it ends up on sk_receive_queue and then gets defer-free'd by skb_attempt_defer_free. The problem happens when we defer freeing an skb (push it on one CPU's defer_list), and don't flush that list before the netns is deleted. In that case, we still have a reference on the xfrm_state that we don't expect at this point. We already drop the skb's dst in the TCP receive path when it's no longer needed, so let's also drop the secpath. At this point, tcp_filter has already called into the LSM hooks that may require the secpath, so it should not be needed anymore. However, in some of those places, the MPTCP extension has just been attached to the skb, so we cannot simply drop all extensions. Fixes: 68822bdf76f1 ("net: generalize skb freeing deferral to per-cpu lists") Reported-by: Xiumei Mu <xmu@redhat.com> Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/5055ba8f8f72bdcb602faa299faca73c280b7735.1739743613.git.sd@queasysnail.net Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-27arp: switch to dev_getbyhwaddr() in arp_req_set_public()Breno Leitao
[ Upstream commit 4eae0ee0f1e6256d0b0b9dd6e72f1d9cf8f72e08 ] The arp_req_set_public() function is called with the rtnl lock held, which provides enough synchronization protection. This makes the RCU variant of dev_getbyhwaddr() unnecessary. Switch to using the simpler dev_getbyhwaddr() function since we already have the required rtnl locking. This change helps maintain consistency in the networking code by using the appropriate helper function for the existing locking context. Since we're not holding the RCU read lock in arp_req_set_public() existing code could trigger false positive locking warnings. Fixes: 941666c2e3e0 ("net: RCU conversion of dev_getbyhwaddr() and arp_ioctl()") Suggested-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: Breno Leitao <leitao@debian.org> Link: https://patch.msgid.link/20250218-arm_fix_selftest-v5-2-d3d6892db9e1@debian.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-27tcp: adjust rcvq_space after updating scaling ratioJakub Kicinski
[ Upstream commit f5da7c45188eea71394bf445655cae2df88a7788 ] Since commit under Fixes we set the window clamp in accordance to newly measured rcvbuf scaling_ratio. If the scaling_ratio decreased significantly we may put ourselves in a situation where windows become smaller than rcvq_space, preventing tcp_rcv_space_adjust() from increasing rcvbuf. The significant decrease of scaling_ratio is far more likely since commit 697a6c8cec03 ("tcp: increase the default TCP scaling ratio"), which increased the "default" scaling ratio from ~30% to 50%. Hitting the bad condition depends a lot on TCP tuning, and drivers at play. One of Meta's workloads hits it reliably under following conditions: - default rcvbuf of 125k - sender MTU 1500, receiver MTU 5000 - driver settles on scaling_ratio of 78 for the config above. Initial rcvq_space gets calculated as TCP_INIT_CWND * tp->advmss (10 * 5k = 50k). Once we find out the true scaling ratio and MSS we clamp the windows to 38k. Triggering the condition also depends on the message sequence of this workload. I can't repro the problem with simple iperf or TCP_RR-style tests. Fixes: a2cbb1603943 ("tcp: Update window clamping condition") Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Link: https://patch.msgid.link/20250217232905.3162187-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21arp: use RCU protection in arp_xmit()Eric Dumazet
[ Upstream commit a42b69f692165ec39db42d595f4f65a4c8f42e44 ] arp_xmit() can be called without RTNL or RCU protection. Use RCU protection to avoid potential UAF. Fixes: 29a26a568038 ("netfilter: Pass struct net into the netfilter hooks") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250207135841.1948589-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21ipv4: icmp: convert to dev_net_rcu()Eric Dumazet
[ Upstream commit 4b8474a0951e605d2a27a2c483da4eb4b8c63760 ] __icmp_send() must ensure rcu_read_lock() is held, as spotted by Jakub. Other ICMP uses of dev_net() seem safe, change them to dev_net_rcu() to get LOCKDEP support. Fixes: dde1bc0e6f86 ("[NETNS]: Add namespace for ICMP replying code.") Closes: https://lore.kernel.org/netdev/20250203153633.46ce0337@kernel.org/ Reported-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250205155120.1676781-9-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21ipv4: use RCU protection in __ip_rt_update_pmtu()Eric Dumazet
[ Upstream commit 139512191bd06f1b496117c76372b2ce372c9a41 ] __ip_rt_update_pmtu() must use RCU protection to make sure the net structure it reads does not disappear. Fixes: 2fbc6e89b2f1 ("ipv4: Update exception handling for multipath routes via same device") Fixes: 1de6b15a434c ("Namespaceify min_pmtu sysctl") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250205155120.1676781-8-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21net: ipv4: Cache pmtu for all packet paths if multipath enabledVladimir Vdovin
[ Upstream commit 7d3f3b4367f315a61fc615e3138f3d320da8c466 ] Check number of paths by fib_info_num_path(), and update_or_create_fnhe() for every path. Problem is that pmtu is cached only for the oif that has received icmp message "need to frag", other oifs will still try to use "default" iface mtu. An example topology showing the problem: | host1 +---------+ | dummy0 | 10.179.20.18/32 mtu9000 +---------+ +-----------+----------------+ +---------+ +---------+ | ens17f0 | 10.179.2.141/31 | ens17f1 | 10.179.2.13/31 +---------+ +---------+ | (all here have mtu 9000) | +------+ +------+ | ro1 | 10.179.2.140/31 | ro2 | 10.179.2.12/31 +------+ +------+ | | ---------+------------+-------------------+------ | +-----+ | ro3 | 10.10.10.10 mtu1500 +-----+ | ======================================== some networks ======================================== | +-----+ | eth0| 10.10.30.30 mtu9000 +-----+ | host2 host1 have enabled multipath and sysctl net.ipv4.fib_multipath_hash_policy = 1: default proto static src 10.179.20.18 nexthop via 10.179.2.12 dev ens17f1 weight 1 nexthop via 10.179.2.140 dev ens17f0 weight 1 When host1 tries to do pmtud from 10.179.20.18/32 to host2, host1 receives at ens17f1 iface an icmp packet from ro3 that ro3 mtu=1500. And host1 caches it in nexthop exceptions cache. Problem is that it is cached only for the iface that has received icmp, and there is no way that ro3 will send icmp msg to host1 via another path. Host1 now have this routes to host2: ip r g 10.10.30.30 sport 30000 dport 443 10.10.30.30 via 10.179.2.12 dev ens17f1 src 10.179.20.18 uid 0 cache expires 521sec mtu 1500 ip r g 10.10.30.30 sport 30033 dport 443 10.10.30.30 via 10.179.2.140 dev ens17f0 src 10.179.20.18 uid 0 cache So when host1 tries again to reach host2 with mtu>1500, if packet flow is lucky enough to be hashed with oif=ens17f1 its ok, if oif=ens17f0 it blackholes and still gets icmp msgs from ro3 to ens17f1, until lucky day when ro3 will send it through another flow to ens17f0. Signed-off-by: Vladimir Vdovin <deliran@verdict.gg> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20241108093427.317942-1-deliran@verdict.gg Signed-off-by: Jakub Kicinski <kuba@kernel.org> Stable-dep-of: 139512191bd0 ("ipv4: use RCU protection in __ip_rt_update_pmtu()") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21ipv4: use RCU protection in inet_select_addr()Eric Dumazet
[ Upstream commit 719817cd293e4fa389e1f69c396f3f816ed5aa41 ] inet_select_addr() must use RCU protection to make sure the net structure it reads does not disappear. Fixes: c4544c724322 ("[NETNS]: Process inet_select_addr inside a namespace.") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250205155120.1676781-7-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21ipv4: use RCU protection in rt_is_expired()Eric Dumazet
[ Upstream commit dd205fcc33d92d54eee4d7f21bb073af9bd5ce2b ] rt_is_expired() must use RCU protection to make sure the net structure it reads does not disappear. Fixes: e84f84f27647 ("netns: place rt_genid into struct net") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250205155120.1676781-6-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-21ipv4: use RCU protection in ipv4_default_advmss()Eric Dumazet
[ Upstream commit 71b8471c93fa0bcab911fcb65da1eb6c4f5f735f ] ipv4_default_advmss() must use RCU protection to make sure the net structure it reads does not disappear. Fixes: 2e9589ff809e ("ipv4: Namespaceify min_adv_mss sysctl knob") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250205155120.1676781-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-17udp: gso: do not drop small packets when PMTU reducesYan Zhai
[ Upstream commit 235174b2bed88501fda689c113c55737f99332d8 ] Commit 4094871db1d6 ("udp: only do GSO if # of segs > 1") avoided GSO for small packets. But the kernel currently dismisses GSO requests only after checking MTU/PMTU on gso_size. This means any packets, regardless of their payload sizes, could be dropped when PMTU becomes smaller than requested gso_size. We encountered this issue in production and it caused a reliability problem that new QUIC connection cannot be established before PMTU cache expired, while non GSO sockets still worked fine at the same time. Ideally, do not check any GSO related constraints when payload size is smaller than requested gso_size, and return EMSGSIZE instead of EINVAL on MTU/PMTU check failure to be more specific on the error cause. Fixes: 4094871db1d6 ("udp: only do GSO if # of segs > 1") Signed-off-by: Yan Zhai <yan@cloudflare.com> Suggested-by: Willem de Bruijn <willemdebruijn.kernel@gmail.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>
2025-02-08tcp: correct handling of extreme memory squeezeJon Maloy
[ Upstream commit 8c670bdfa58e48abad1d5b6ca1ee843ca91f7303 ] Testing with iperf3 using the "pasta" protocol splicer has revealed a problem in the way tcp handles window advertising in extreme memory squeeze situations. Under memory pressure, a socket endpoint may temporarily advertise a zero-sized window, but this is not stored as part of the socket data. The reasoning behind this is that it is considered a temporary setting which shouldn't influence any further calculations. However, if we happen to stall at an unfortunate value of the current window size, the algorithm selecting a new value will consistently fail to advertise a non-zero window once we have freed up enough memory. This means that this side's notion of the current window size is different from the one last advertised to the peer, causing the latter to not send any data to resolve the sitution. The problem occurs on the iperf3 server side, and the socket in question is a completely regular socket with the default settings for the fedora40 kernel. We do not use SO_PEEK or SO_RCVBUF on the socket. The following excerpt of a logging session, with own comments added, shows more in detail what is happening: // tcp_v4_rcv(->) // tcp_rcv_established(->) [5201<->39222]: ==== Activating log @ net/ipv4/tcp_input.c/tcp_data_queue()/5257 ==== [5201<->39222]: tcp_data_queue(->) [5201<->39222]: DROPPING skb [265600160..265665640], reason: SKB_DROP_REASON_PROTO_MEM [rcv_nxt 265600160, rcv_wnd 262144, snt_ack 265469200, win_now 131184] [copied_seq 259909392->260034360 (124968), unread 5565800, qlen 85, ofoq 0] [OFO queue: gap: 65480, len: 0] [5201<->39222]: tcp_data_queue(<-) [5201<->39222]: __tcp_transmit_skb(->) [tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160] [5201<->39222]: tcp_select_window(->) [5201<->39222]: (inet_csk(sk)->icsk_ack.pending & ICSK_ACK_NOMEM) ? --> TRUE [tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160] returning 0 [5201<->39222]: tcp_select_window(<-) [5201<->39222]: ADVERTISING WIN 0, ACK_SEQ: 265600160 [5201<->39222]: [__tcp_transmit_skb(<-) [5201<->39222]: tcp_rcv_established(<-) [5201<->39222]: tcp_v4_rcv(<-) // Receive queue is at 85 buffers and we are out of memory. // We drop the incoming buffer, although it is in sequence, and decide // to send an advertisement with a window of zero. // We don't update tp->rcv_wnd and tp->rcv_wup accordingly, which means // we unconditionally shrink the window. [5201<->39222]: tcp_recvmsg_locked(->) [5201<->39222]: __tcp_cleanup_rbuf(->) tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160 [5201<->39222]: [new_win = 0, win_now = 131184, 2 * win_now = 262368] [5201<->39222]: [new_win >= (2 * win_now) ? --> time_to_ack = 0] [5201<->39222]: NOT calling tcp_send_ack() [tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160] [5201<->39222]: __tcp_cleanup_rbuf(<-) [rcv_nxt 265600160, rcv_wnd 262144, snt_ack 265469200, win_now 131184] [copied_seq 260040464->260040464 (0), unread 5559696, qlen 85, ofoq 0] returning 6104 bytes [5201<->39222]: tcp_recvmsg_locked(<-) // After each read, the algorithm for calculating the new receive // window in __tcp_cleanup_rbuf() finds it is too small to advertise // or to update tp->rcv_wnd. // Meanwhile, the peer thinks the window is zero, and will not send // any more data to trigger an update from the interrupt mode side. [5201<->39222]: tcp_recvmsg_locked(->) [5201<->39222]: __tcp_cleanup_rbuf(->) tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160 [5201<->39222]: [new_win = 262144, win_now = 131184, 2 * win_now = 262368] [5201<->39222]: [new_win >= (2 * win_now) ? --> time_to_ack = 0] [5201<->39222]: NOT calling tcp_send_ack() [tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160] [5201<->39222]: __tcp_cleanup_rbuf(<-) [rcv_nxt 265600160, rcv_wnd 262144, snt_ack 265469200, win_now 131184] [copied_seq 260099840->260171536 (71696), unread 5428624, qlen 83, ofoq 0] returning 131072 bytes [5201<->39222]: tcp_recvmsg_locked(<-) // The above pattern repeats again and again, since nothing changes // between the reads. [...] [5201<->39222]: tcp_recvmsg_locked(->) [5201<->39222]: __tcp_cleanup_rbuf(->) tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160 [5201<->39222]: [new_win = 262144, win_now = 131184, 2 * win_now = 262368] [5201<->39222]: [new_win >= (2 * win_now) ? --> time_to_ack = 0] [5201<->39222]: NOT calling tcp_send_ack() [tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160] [5201<->39222]: __tcp_cleanup_rbuf(<-) [rcv_nxt 265600160, rcv_wnd 262144, snt_ack 265469200, win_now 131184] [copied_seq 265600160->265600160 (0), unread 0, qlen 0, ofoq 0] returning 54672 bytes [5201<->39222]: tcp_recvmsg_locked(<-) // The receive queue is empty, but no new advertisement has been sent. // The peer still thinks the receive window is zero, and sends nothing. // We have ended up in a deadlock situation. Note that well behaved endpoints will send win0 probes, so the problem will not occur. Furthermore, we have observed that in these situations this side may send out an updated 'th->ack_seq´ which is not stored in tp->rcv_wup as it should be. Backing ack_seq seems to be harmless, but is of course still wrong from a protocol viewpoint. We fix this by updating the socket state correctly when a packet has been dropped because of memory exhaustion and we have to advertize a zero window. Further testing shows that the connection recovers neatly from the squeeze situation, and traffic can continue indefinitely. Fixes: e2142825c120 ("net: tcp: send zero-window ACK when no memory") Cc: Menglong Dong <menglong8.dong@gmail.com> Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: Jon Maloy <jmaloy@redhat.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Neal Cardwell <ncardwell@google.com> Link: https://patch.msgid.link/20250127231304.1465565-1-jmaloy@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08ipmr: do not call mr_mfc_uses_dev() for unres entriesEric Dumazet
[ Upstream commit 15a901361ec3fb1c393f91880e1cbf24ec0a88bd ] syzbot found that calling mr_mfc_uses_dev() for unres entries would crash [1], because c->mfc_un.res.minvif / c->mfc_un.res.maxvif alias to "struct sk_buff_head unresolved", which contain two pointers. This code never worked, lets remove it. [1] Unable to handle kernel paging request at virtual address ffff5fff2d536613 KASAN: maybe wild-memory-access in range [0xfffefff96a9b3098-0xfffefff96a9b309f] Modules linked in: CPU: 1 UID: 0 PID: 7321 Comm: syz.0.16 Not tainted 6.13.0-rc7-syzkaller-g1950a0af2d55 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : mr_mfc_uses_dev net/ipv4/ipmr_base.c:290 [inline] pc : mr_table_dump+0x5a4/0x8b0 net/ipv4/ipmr_base.c:334 lr : mr_mfc_uses_dev net/ipv4/ipmr_base.c:289 [inline] lr : mr_table_dump+0x694/0x8b0 net/ipv4/ipmr_base.c:334 Call trace: mr_mfc_uses_dev net/ipv4/ipmr_base.c:290 [inline] (P) mr_table_dump+0x5a4/0x8b0 net/ipv4/ipmr_base.c:334 (P) mr_rtm_dumproute+0x254/0x454 net/ipv4/ipmr_base.c:382 ipmr_rtm_dumproute+0x248/0x4b4 net/ipv4/ipmr.c:2648 rtnl_dump_all+0x2e4/0x4e8 net/core/rtnetlink.c:4327 rtnl_dumpit+0x98/0x1d0 net/core/rtnetlink.c:6791 netlink_dump+0x4f0/0xbc0 net/netlink/af_netlink.c:2317 netlink_recvmsg+0x56c/0xe64 net/netlink/af_netlink.c:1973 sock_recvmsg_nosec net/socket.c:1033 [inline] sock_recvmsg net/socket.c:1055 [inline] sock_read_iter+0x2d8/0x40c net/socket.c:1125 new_sync_read fs/read_write.c:484 [inline] vfs_read+0x740/0x970 fs/read_write.c:565 ksys_read+0x15c/0x26c fs/read_write.c:708 Fixes: cb167893f41e ("net: Plumb support for filtering ipv4 and ipv6 multicast route dumps") Reported-by: syzbot+5cfae50c0e5f2c500013@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/678fe2d1.050a0220.15cac.00b3.GAE@google.com/T/#u Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250121181241.841212-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08xfrm: Add an inbound percpu state cache.Steffen Klassert
[ Upstream commit 81a331a0e72ddc2f75092603d9577bd1a0ca23ad ] Now that we can have percpu xfrm states, the number of active states might increase. To get a better lookup performance, we add a percpu cache to cache the used inbound xfrm states. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Tested-by: Antony Antony <antony.antony@secunet.com> Tested-by: Tobias Brunner <tobias@strongswan.org> Stable-dep-of: e952837f3ddb ("xfrm: state: fix out-of-bounds read during lookup") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08tcp_cubic: fix incorrect HyStart round start detectionMahdi Arghavani
[ Upstream commit 25c1a9ca53db5780757e7f53e688b8f916821baa ] I noticed that HyStart incorrectly marks the start of rounds, leading to inaccurate measurements of ACK train lengths and resetting the `ca->sample_cnt` variable. This inaccuracy can impact HyStart's functionality in terminating exponential cwnd growth during Slow-Start, potentially degrading TCP performance. The issue arises because the changes introduced in commit 4e1fddc98d25 ("tcp_cubic: fix spurious Hystart ACK train detections for not-cwnd-limited flows") moved the caller of the `bictcp_hystart_reset` function inside the `hystart_update` function. This modification added an additional condition for triggering the caller, requiring that (tcp_snd_cwnd(tp) >= hystart_low_window) must also be satisfied before invoking `bictcp_hystart_reset`. This fix ensures that `bictcp_hystart_reset` is correctly called at the start of a new round, regardless of the congestion window size. This is achieved by moving the condition (tcp_snd_cwnd(tp) >= hystart_low_window) from before calling `bictcp_hystart_reset` to after it. I tested with a client and a server connected through two Linux software routers. In this setup, the minimum RTT was 150 ms, the bottleneck bandwidth was 50 Mbps, and the bottleneck buffer size was 1 BDP, calculated as (50M / 1514 / 8) * 0.150 = 619 packets. I conducted the test twice, transferring data from the server to the client for 1.5 seconds. Before the patch was applied, HYSTART-DELAY stopped the exponential growth of cwnd when cwnd = 516, and the bottleneck link was not yet saturated (516 < 619). After the patch was applied, HYSTART-ACK-TRAIN stopped the exponential growth of cwnd when cwnd = 632, and the bottleneck link was saturated (632 > 619). In this test, applying the patch resulted in 300 KB more data delivered. Fixes: 4e1fddc98d25 ("tcp_cubic: fix spurious Hystart ACK train detections for not-cwnd-limited flows") Signed-off-by: Mahdi Arghavani <ma.arghavani@yahoo.com> Reviewed-by: Jason Xing <kerneljasonxing@gmail.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Haibo Zhang <haibo.zhang@otago.ac.nz> Cc: David Eyers <david.eyers@otago.ac.nz> Cc: Abbas Arghavani <abbas.arghavani@mdu.se> Reviewed-by: Neal Cardwell <ncardwell@google.com> Tested-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08inet: ipmr: fix data-racesEric Dumazet
[ Upstream commit 3440fa34ad99d471f1085bc2f4dedeaebc310261 ] Following fields of 'struct mr_mfc' can be updated concurrently (no lock protection) from ip_mr_forward() and ip6_mr_forward() - bytes - pkt - wrong_if - lastuse They also can be read from other functions. Convert bytes, pkt and wrong_if to atomic_long_t, and use READ_ONCE()/WRITE_ONCE() for lastuse. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://patch.msgid.link/20250114221049.1190631-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>