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2023-05-16devlink: Fix crash with CONFIG_NET_NS=nIdo Schimmel
'__net_initdata' becomes a no-op with CONFIG_NET_NS=y, but when this option is disabled it becomes '__initdata', which means the data can be freed after the initialization phase. This annotation is obviously incorrect for the devlink net device notifier block which is still registered after the initialization phase [1]. Fix this crash by removing the '__net_initdata' annotation. [1] general protection fault, probably for non-canonical address 0xcccccccccccccccc: 0000 [#1] PREEMPT SMP CPU: 3 PID: 117 Comm: (udev-worker) Not tainted 6.4.0-rc1-custom-gdf0acdc59b09 #64 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc37 04/01/2014 RIP: 0010:notifier_call_chain+0x58/0xc0 [...] Call Trace: <TASK> dev_set_mac_address+0x85/0x120 dev_set_mac_address_user+0x30/0x50 do_setlink+0x219/0x1270 rtnl_setlink+0xf7/0x1a0 rtnetlink_rcv_msg+0x142/0x390 netlink_rcv_skb+0x58/0x100 netlink_unicast+0x188/0x270 netlink_sendmsg+0x214/0x470 __sys_sendto+0x12f/0x1a0 __x64_sys_sendto+0x24/0x30 do_syscall_64+0x38/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: e93c9378e33f ("devlink: change per-devlink netdev notifier to static one") Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Closes: https://lore.kernel.org/netdev/600ddf9e-589a-2aa0-7b69-a438f833ca10@samsung.com/ Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Link: https://lore.kernel.org/r/20230515162925.1144416-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-16Merge tag 'for-netdev' of ↵Jakub Kicinski
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next Daniel Borkmann says: ==================== pull-request: bpf-next 2023-05-16 We've added 57 non-merge commits during the last 19 day(s) which contain a total of 63 files changed, 3293 insertions(+), 690 deletions(-). The main changes are: 1) Add precision propagation to verifier for subprogs and callbacks, from Andrii Nakryiko. 2) Improve BPF's {g,s}setsockopt() handling with wrong option lengths, from Stanislav Fomichev. 3) Utilize pahole v1.25 for the kernel's BTF generation to filter out inconsistent function prototypes, from Alan Maguire. 4) Various dyn-pointer verifier improvements to relax restrictions, from Daniel Rosenberg. 5) Add a new bpf_task_under_cgroup() kfunc for designated task, from Feng Zhou. 6) Unblock tests for arm64 BPF CI after ftrace supporting direct call, from Florent Revest. 7) Add XDP hint kfunc metadata for RX hash/timestamp for igc, from Jesper Dangaard Brouer. 8) Add several new dyn-pointer kfuncs to ease their usability, from Joanne Koong. 9) Add in-depth LRU internals description and dot function graph, from Joe Stringer. 10) Fix KCSAN report on bpf_lru_list when accessing node->ref, from Martin KaFai Lau. 11) Only dump unprivileged_bpf_disabled log warning upon write, from Kui-Feng Lee. 12) Extend test_progs to directly passing allow/denylist file, from Stephen Veiss. 13) Fix BPF trampoline memleak upon failure attaching to fentry, from Yafang Shao. 14) Fix emitting struct bpf_tcp_sock type in vmlinux BTF, from Yonghong Song. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (57 commits) bpf: Fix memleak due to fentry attach failure bpf: Remove bpf trampoline selector bpf, arm64: Support struct arguments in the BPF trampoline bpftool: JIT limited misreported as negative value on aarch64 bpf: fix calculation of subseq_idx during precision backtracking bpf: Remove anonymous union in bpf_kfunc_call_arg_meta bpf: Document EFAULT changes for sockopt selftests/bpf: Correctly handle optlen > 4096 selftests/bpf: Update EFAULT {g,s}etsockopt selftests bpf: Don't EFAULT for {g,s}setsockopt with wrong optlen libbpf: fix offsetof() and container_of() to work with CO-RE bpf: Address KCSAN report on bpf_lru_list bpf: Add --skip_encoding_btf_inconsistent_proto, --btf_gen_optimized to pahole flags for v1.25 selftests/bpf: Accept mem from dynptr in helper funcs bpf: verifier: Accept dynptr mem as mem in helpers selftests/bpf: Check overflow in optional buffer selftests/bpf: Test allowing NULL buffer in dynptr slice bpf: Allow NULL buffers in bpf_dynptr_slice(_rw) selftests/bpf: Add testcase for bpf_task_under_cgroup bpf: Add bpf_task_under_cgroup() kfunc ... ==================== Link: https://lore.kernel.org/r/20230515225603.27027-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-16wifi: mac80211: recalc chanctx mindef before assigningJohannes Berg
When we allocate a new channel context, or find an existing one that is compatible, we currently assign it to a link before its mindef is updated. This leads to strange situations, especially in link switching where you switch to an 80 MHz link and expect it to be active immediately, but the mindef is still configured to 20 MHz while assigning. Also, it's strange that the chandef passed to the assign method's argument is wider than the one in the context. Fix this by calculating the mindef with the new link considered before calling the driver. In particular, this fixes an iwlwifi problem during link switch where the firmware would assert because the (link) station that was added for the AP is configured to transmit at a bandwidth that's wider than the channel context that it's configured on. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Gregory Greenman <gregory.greenman@intel.com> Link: https://lore.kernel.org/r/20230504134511.828474-5-gregory.greenman@intel.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2023-05-16wifi: mac80211: consider reserved chanctx for mindefJohannes Berg
When a chanctx is reserved for a new vif and we recalculate the minimal definition for it, we need to consider the new interface it's being reserved for before we assign it, so it can be used directly with the correct min channel width. Fix the code to - optionally - consider that, and use that option just before doing the reassignment. Also, when considering channel context reservations, we should only consider the one link we're currently working with. Change the boolean argument to a link pointer to do that. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Gregory Greenman <gregory.greenman@intel.com> Link: https://lore.kernel.org/r/20230504134511.828474-4-gregory.greenman@intel.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2023-05-16wifi: mac80211: simplify chanctx allocationJohannes Berg
There's no need to call ieee80211_recalc_chanctx_min_def() since it cannot and won't call the driver anyway; just use _ieee80211_recalc_chanctx_min_def() instead. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Gregory Greenman <gregory.greenman@intel.com> Link: https://lore.kernel.org/r/20230504134511.828474-3-gregory.greenman@intel.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2023-05-16wifi: mac80211: Abort running color change when stopping the APMichael Lee
When stopping the AP, there might be a color change in progress. It should be deactivated here, or the driver might later finalize a color change on a stopped AP. Fixes: 5f9404abdf2a (mac80211: add support for BSS color change) Signed-off-by: Michael Lee <michael-cy.lee@mediatek.com> Link: https://lore.kernel.org/r/20230504080441.22958-1-michael-cy.lee@mediatek.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2023-05-16wifi: mac80211: fix min center freq offset tracingJohannes Berg
We need to set the correct trace variable, otherwise we're overwriting something else instead and the right one that we print later is not initialized. Fixes: b6011960f392 ("mac80211: handle channel frequency offset") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Gregory Greenman <gregory.greenman@intel.com> Link: https://lore.kernel.org/r/20230504134511.828474-2-gregory.greenman@intel.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2023-05-16wifi: mac80211: Fix puncturing bitmap handling in __ieee80211_csa_finalize()Christophe JAILLET
'changed' can be OR'ed with BSS_CHANGED_EHT_PUNCTURING which is larger than an u32. So, turn 'changed' into an u64 and update ieee80211_set_after_csa_beacon() accordingly. In the commit in Fixes, only ieee80211_start_ap() was updated. Fixes: 2cc25e4b2a04 ("wifi: mac80211: configure puncturing bitmap") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by: Simon Horman <simon.horman@corigine.com> Link: https://lore.kernel.org/r/e84a3f80fe536787f7a2c7180507efc36cd14f95.1682358088.git.christophe.jaillet@wanadoo.fr Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2023-05-16wifi: mac80211: fortify the spinlock against deadlock by interruptMirsad Goran Todorovac
In the function ieee80211_tx_dequeue() there is a particular locking sequence: begin: spin_lock(&local->queue_stop_reason_lock); q_stopped = local->queue_stop_reasons[q]; spin_unlock(&local->queue_stop_reason_lock); However small the chance (increased by ftracetest), an asynchronous interrupt can occur in between of spin_lock() and spin_unlock(), and the interrupt routine will attempt to lock the same &local->queue_stop_reason_lock again. This will cause a costly reset of the CPU and the wifi device or an altogether hang in the single CPU and single core scenario. The only remaining spin_lock(&local->queue_stop_reason_lock) that did not disable interrupts was patched, which should prevent any deadlocks on the same CPU/core and the same wifi device. This is the probable trace of the deadlock: kernel: ================================ kernel: WARNING: inconsistent lock state kernel: 6.3.0-rc6-mt-20230401-00001-gf86822a1170f #4 Tainted: G W kernel: -------------------------------- kernel: inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. kernel: kworker/5:0/25656 [HC0[0]:SC0[0]:HE1:SE1] takes: kernel: ffff9d6190779478 (&local->queue_stop_reason_lock){+.?.}-{2:2}, at: return_to_handler+0x0/0x40 kernel: {IN-SOFTIRQ-W} state was registered at: kernel: lock_acquire+0xc7/0x2d0 kernel: _raw_spin_lock+0x36/0x50 kernel: ieee80211_tx_dequeue+0xb4/0x1330 [mac80211] kernel: iwl_mvm_mac_itxq_xmit+0xae/0x210 [iwlmvm] kernel: iwl_mvm_mac_wake_tx_queue+0x2d/0xd0 [iwlmvm] kernel: ieee80211_queue_skb+0x450/0x730 [mac80211] kernel: __ieee80211_xmit_fast.constprop.66+0x834/0xa50 [mac80211] kernel: __ieee80211_subif_start_xmit+0x217/0x530 [mac80211] kernel: ieee80211_subif_start_xmit+0x60/0x580 [mac80211] kernel: dev_hard_start_xmit+0xb5/0x260 kernel: __dev_queue_xmit+0xdbe/0x1200 kernel: neigh_resolve_output+0x166/0x260 kernel: ip_finish_output2+0x216/0xb80 kernel: __ip_finish_output+0x2a4/0x4d0 kernel: ip_finish_output+0x2d/0xd0 kernel: ip_output+0x82/0x2b0 kernel: ip_local_out+0xec/0x110 kernel: igmpv3_sendpack+0x5c/0x90 kernel: igmp_ifc_timer_expire+0x26e/0x4e0 kernel: call_timer_fn+0xa5/0x230 kernel: run_timer_softirq+0x27f/0x550 kernel: __do_softirq+0xb4/0x3a4 kernel: irq_exit_rcu+0x9b/0xc0 kernel: sysvec_apic_timer_interrupt+0x80/0xa0 kernel: asm_sysvec_apic_timer_interrupt+0x1f/0x30 kernel: _raw_spin_unlock_irqrestore+0x3f/0x70 kernel: free_to_partial_list+0x3d6/0x590 kernel: __slab_free+0x1b7/0x310 kernel: kmem_cache_free+0x52d/0x550 kernel: putname+0x5d/0x70 kernel: do_sys_openat2+0x1d7/0x310 kernel: do_sys_open+0x51/0x80 kernel: __x64_sys_openat+0x24/0x30 kernel: do_syscall_64+0x5c/0x90 kernel: entry_SYSCALL_64_after_hwframe+0x72/0xdc kernel: irq event stamp: 5120729 kernel: hardirqs last enabled at (5120729): [<ffffffff9d149936>] trace_graph_return+0xd6/0x120 kernel: hardirqs last disabled at (5120728): [<ffffffff9d149950>] trace_graph_return+0xf0/0x120 kernel: softirqs last enabled at (5069900): [<ffffffff9cf65b60>] return_to_handler+0x0/0x40 kernel: softirqs last disabled at (5067555): [<ffffffff9cf65b60>] return_to_handler+0x0/0x40 kernel: other info that might help us debug this: kernel: Possible unsafe locking scenario: kernel: CPU0 kernel: ---- kernel: lock(&local->queue_stop_reason_lock); kernel: <Interrupt> kernel: lock(&local->queue_stop_reason_lock); kernel: *** DEADLOCK *** kernel: 8 locks held by kworker/5:0/25656: kernel: #0: ffff9d618009d138 ((wq_completion)events_freezable){+.+.}-{0:0}, at: process_one_work+0x1ca/0x530 kernel: #1: ffffb1ef4637fe68 ((work_completion)(&local->restart_work)){+.+.}-{0:0}, at: process_one_work+0x1ce/0x530 kernel: #2: ffffffff9f166548 (rtnl_mutex){+.+.}-{3:3}, at: return_to_handler+0x0/0x40 kernel: #3: ffff9d6190778728 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: return_to_handler+0x0/0x40 kernel: #4: ffff9d619077b480 (&mvm->mutex){+.+.}-{3:3}, at: return_to_handler+0x0/0x40 kernel: #5: ffff9d61907bacd8 (&trans_pcie->mutex){+.+.}-{3:3}, at: return_to_handler+0x0/0x40 kernel: #6: ffffffff9ef9cda0 (rcu_read_lock){....}-{1:2}, at: iwl_mvm_queue_state_change+0x59/0x3a0 [iwlmvm] kernel: #7: ffffffff9ef9cda0 (rcu_read_lock){....}-{1:2}, at: iwl_mvm_mac_itxq_xmit+0x42/0x210 [iwlmvm] kernel: stack backtrace: kernel: CPU: 5 PID: 25656 Comm: kworker/5:0 Tainted: G W 6.3.0-rc6-mt-20230401-00001-gf86822a1170f #4 kernel: Hardware name: LENOVO 82H8/LNVNB161216, BIOS GGCN51WW 11/16/2022 kernel: Workqueue: events_freezable ieee80211_restart_work [mac80211] kernel: Call Trace: kernel: <TASK> kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: dump_stack_lvl+0x5f/0xa0 kernel: dump_stack+0x14/0x20 kernel: print_usage_bug.part.46+0x208/0x2a0 kernel: mark_lock.part.47+0x605/0x630 kernel: ? sched_clock+0xd/0x20 kernel: ? trace_clock_local+0x14/0x30 kernel: ? __rb_reserve_next+0x5f/0x490 kernel: ? _raw_spin_lock+0x1b/0x50 kernel: __lock_acquire+0x464/0x1990 kernel: ? mark_held_locks+0x4e/0x80 kernel: lock_acquire+0xc7/0x2d0 kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: ? ftrace_return_to_handler+0x8b/0x100 kernel: ? preempt_count_add+0x4/0x70 kernel: _raw_spin_lock+0x36/0x50 kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: ieee80211_tx_dequeue+0xb4/0x1330 [mac80211] kernel: ? prepare_ftrace_return+0xc5/0x190 kernel: ? ftrace_graph_func+0x16/0x20 kernel: ? 0xffffffffc02ab0b1 kernel: ? lock_acquire+0xc7/0x2d0 kernel: ? iwl_mvm_mac_itxq_xmit+0x42/0x210 [iwlmvm] kernel: ? ieee80211_tx_dequeue+0x9/0x1330 [mac80211] kernel: ? __rcu_read_lock+0x4/0x40 kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: iwl_mvm_mac_itxq_xmit+0xae/0x210 [iwlmvm] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: iwl_mvm_queue_state_change+0x311/0x3a0 [iwlmvm] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: iwl_mvm_wake_sw_queue+0x17/0x20 [iwlmvm] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: iwl_txq_gen2_unmap+0x1c9/0x1f0 [iwlwifi] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: iwl_txq_gen2_free+0x55/0x130 [iwlwifi] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: iwl_txq_gen2_tx_free+0x63/0x80 [iwlwifi] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: _iwl_trans_pcie_gen2_stop_device+0x3f3/0x5b0 [iwlwifi] kernel: ? _iwl_trans_pcie_gen2_stop_device+0x9/0x5b0 [iwlwifi] kernel: ? mutex_lock_nested+0x4/0x30 kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: iwl_trans_pcie_gen2_stop_device+0x5f/0x90 [iwlwifi] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: iwl_mvm_stop_device+0x78/0xd0 [iwlmvm] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: __iwl_mvm_mac_start+0x114/0x210 [iwlmvm] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: iwl_mvm_mac_start+0x76/0x150 [iwlmvm] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: drv_start+0x79/0x180 [mac80211] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: ieee80211_reconfig+0x1523/0x1ce0 [mac80211] kernel: ? synchronize_net+0x4/0x50 kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: ieee80211_restart_work+0x108/0x170 [mac80211] kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: process_one_work+0x250/0x530 kernel: ? ftrace_regs_caller_end+0x66/0x66 kernel: worker_thread+0x48/0x3a0 kernel: ? __pfx_worker_thread+0x10/0x10 kernel: kthread+0x10f/0x140 kernel: ? __pfx_kthread+0x10/0x10 kernel: ret_from_fork+0x29/0x50 kernel: </TASK> Fixes: 4444bc2116ae ("wifi: mac80211: Proper mark iTXQs for resumption") Link: https://lore.kernel.org/all/1f58a0d1-d2b9-d851-73c3-93fcc607501c@alu.unizg.hr/ Reported-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr> Cc: Gregory Greenman <gregory.greenman@intel.com> Cc: Johannes Berg <johannes.berg@intel.com> Link: https://lore.kernel.org/all/cdc80531-f25f-6f9d-b15f-25e16130b53a@alu.unizg.hr/ Cc: David S. Miller <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Leon Romanovsky <leon@kernel.org> Cc: Alexander Wetzel <alexander@wetzel-home.de> Signed-off-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr> Reviewed-by: Leon Romanovsky <leonro@nvidia.com> Reviewed-by: tag, or it goes automatically? Link: https://lore.kernel.org/r/20230425164005.25272-1-mirsad.todorovac@alu.unizg.hr Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2023-05-16wifi: cfg80211: Drop entries with invalid BSSIDs in RNRIlan Peer
Ignore AP information for entries that include an invalid BSSID in the TBTT information field, e.g., all zeros BSSIDs. Fixes: c8cb5b854b40 ("nl80211/cfg80211: support 6 GHz scanning") Signed-off-by: Ilan Peer <ilan.peer@intel.com> Signed-off-by: Gregory Greenman <gregory.greenman@intel.com> Link: https://lore.kernel.org/r/20230424103224.5e65d04d1448.Ic10c8577ae4a85272c407106c9d0a2ecb5372743@changeid Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2023-05-15can: j1939: recvmsg(): allow MSG_CMSG_COMPAT flagOliver Hartkopp
The control message provided by J1939 support MSG_CMSG_COMPAT but blocked recvmsg() syscalls that have set this flag, i.e. on 32bit user space on 64 bit kernels. Link: https://github.com/hartkopp/can-isotp/issues/59 Cc: Oleksij Rempel <o.rempel@pengutronix.de> Suggested-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Tested-by: Oleksij Rempel <o.rempel@pengutronix.de> Acked-by: Oleksij Rempel <o.rempel@pengutronix.de> Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol") Link: https://lore.kernel.org/20230505110308.81087-3-mkl@pengutronix.de Cc: stable@vger.kernel.org Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2023-05-15can: isotp: recvmsg(): allow MSG_CMSG_COMPAT flagOliver Hartkopp
The control message provided by isotp support MSG_CMSG_COMPAT but blocked recvmsg() syscalls that have set this flag, i.e. on 32bit user space on 64 bit kernels. Link: https://github.com/hartkopp/can-isotp/issues/59 Cc: Oleksij Rempel <o.rempel@pengutronix.de> Suggested-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Fixes: 42bf50a1795a ("can: isotp: support MSG_TRUNC flag when reading from socket") Link: https://lore.kernel.org/20230505110308.81087-2-mkl@pengutronix.de Cc: stable@vger.kernel.org Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2023-05-15net: set FMODE_NOWAIT for socketsJens Axboe
The socket read/write functions deal with O_NONBLOCK and IOCB_NOWAIT just fine, so we can flag them as being FMODE_NOWAIT compliant. With this, we can remove socket special casing in io_uring when checking if a file type is sane for nonblocking IO, and it's also the defined way to flag file types as such in the kernel. Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: netdev@vger.kernel.org Reviewed-by: Paolo Abeni <pabeni@redhat.com> Link: https://lore.kernel.org/r/20230509151910.183637-2-axboe@kernel.dk Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-05-15nfc: llcp: fix possible use of uninitialized variable in nfc_llcp_send_connect()Krzysztof Kozlowski
If sock->service_name is NULL, the local variable service_name_tlv_length will not be assigned by nfc_llcp_build_tlv(), later leading to using value frmo the stack. Smatch warning: net/nfc/llcp_commands.c:442 nfc_llcp_send_connect() error: uninitialized symbol 'service_name_tlv_length'. Fixes: de9e5aeb4f40 ("NFC: llcp: Fix usage of llcp_add_tlv()") Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-15tipc: check the bearer min mtu properly when setting it by netlinkXin Long
Checking the bearer min mtu with tipc_udp_mtu_bad() only works for IPv4 UDP bearer, and IPv6 UDP bearer has a different value for the min mtu. This patch checks with encap_hlen + TIPC_MIN_BEARER_MTU for min mtu, which works for both IPv4 and IPv6 UDP bearer. Note that tipc_udp_mtu_bad() is still used to check media min mtu in __tipc_nl_media_set(), as m->mtu currently is only used by the IPv4 UDP bearer as its default mtu value. Fixes: 682cd3cf946b ("tipc: confgiure and apply UDP bearer MTU on running links") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-15tipc: do not update mtu if msg_max is too small in mtu negotiationXin Long
When doing link mtu negotiation, a malicious peer may send Activate msg with a very small mtu, e.g. 4 in Shuang's testing, without checking for the minimum mtu, l->mtu will be set to 4 in tipc_link_proto_rcv(), then n->links[bearer_id].mtu is set to 4294967228, which is a overflow of '4 - INT_H_SIZE - EMSG_OVERHEAD' in tipc_link_mss(). With tipc_link.mtu = 4, tipc_link_xmit() kept printing the warning: tipc: Too large msg, purging xmit list 1 5 0 40 4! tipc: Too large msg, purging xmit list 1 15 0 60 4! And with tipc_link_entry.mtu 4294967228, a huge skb was allocated in named_distribute(), and when purging it in tipc_link_xmit(), a crash was even caused: general protection fault, probably for non-canonical address 0x2100001011000dd: 0000 [#1] PREEMPT SMP PTI CPU: 0 PID: 0 Comm: swapper/0 Kdump: loaded Not tainted 6.3.0.neta #19 RIP: 0010:kfree_skb_list_reason+0x7e/0x1f0 Call Trace: <IRQ> skb_release_data+0xf9/0x1d0 kfree_skb_reason+0x40/0x100 tipc_link_xmit+0x57a/0x740 [tipc] tipc_node_xmit+0x16c/0x5c0 [tipc] tipc_named_node_up+0x27f/0x2c0 [tipc] tipc_node_write_unlock+0x149/0x170 [tipc] tipc_rcv+0x608/0x740 [tipc] tipc_udp_recv+0xdc/0x1f0 [tipc] udp_queue_rcv_one_skb+0x33e/0x620 udp_unicast_rcv_skb.isra.72+0x75/0x90 __udp4_lib_rcv+0x56d/0xc20 ip_protocol_deliver_rcu+0x100/0x2d0 This patch fixes it by checking the new mtu against tipc_bearer_min_mtu(), and not updating mtu if it is too small. Fixes: ed193ece2649 ("tipc: simplify link mtu negotiation") Reported-by: Shuang Li <shuali@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-15tipc: add tipc_bearer_min_mtu to calculate min mtuXin Long
As different media may requires different min mtu, and even the same media with different net family requires different min mtu, add tipc_bearer_min_mtu() to calculate min mtu accordingly. This API will be used to check the new mtu when doing the link mtu negotiation in the next patch. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Jon Maloy <jmaloy@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-15sch_htb: Allow HTB priority parameter in offload modeNaveen Mamindlapalli
The current implementation of HTB offload returns the EINVAL error for unsupported parameters like prio and quantum. This patch removes the error returning checks for 'prio' parameter and populates its value to tc_htb_qopt_offload structure such that driver can use the same. Add prio parameter check in mlx5 driver, as mlx5 devices are not capable of supporting the prio parameter when htb offload is used. Report error if prio parameter is set to a non-default value. Signed-off-by: Naveen Mamindlapalli <naveenm@marvell.com> Co-developed-by: Rahul Rameshbabu <rrameshbabu@nvidia.com> Signed-off-by: Rahul Rameshbabu <rrameshbabu@nvidia.com> Signed-off-by: Hariprasad Kelam <hkelam@marvell.com> Signed-off-by: Sunil Kovvuri Goutham <sgoutham@marvell.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-15net: Remove low_thresh in ip defragAngus Chen
As low_thresh has no work in fragment reassembles,del it. And Mark it deprecated in sysctl Document. Signed-off-by: Angus Chen <angus.chen@jaguarmicro.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-15net: nsh: Use correct mac_offset to unwind gso skb in nsh_gso_segment()Dong Chenchen
As the call trace shows, skb_panic was caused by wrong skb->mac_header in nsh_gso_segment(): invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 3 PID: 2737 Comm: syz Not tainted 6.3.0-next-20230505 #1 RIP: 0010:skb_panic+0xda/0xe0 call Trace: skb_push+0x91/0xa0 nsh_gso_segment+0x4f3/0x570 skb_mac_gso_segment+0x19e/0x270 __skb_gso_segment+0x1e8/0x3c0 validate_xmit_skb+0x452/0x890 validate_xmit_skb_list+0x99/0xd0 sch_direct_xmit+0x294/0x7c0 __dev_queue_xmit+0x16f0/0x1d70 packet_xmit+0x185/0x210 packet_snd+0xc15/0x1170 packet_sendmsg+0x7b/0xa0 sock_sendmsg+0x14f/0x160 The root cause is: nsh_gso_segment() use skb->network_header - nhoff to reset mac_header in skb_gso_error_unwind() if inner-layer protocol gso fails. However, skb->network_header may be reset by inner-layer protocol gso function e.g. mpls_gso_segment. skb->mac_header reset by the inaccurate network_header will be larger than skb headroom. nsh_gso_segment nhoff = skb->network_header - skb->mac_header; __skb_pull(skb,nsh_len) skb_mac_gso_segment mpls_gso_segment skb_reset_network_header(skb);//skb->network_header+=nsh_len return -EINVAL; skb_gso_error_unwind skb_push(skb, nsh_len); skb->mac_header = skb->network_header - nhoff; // skb->mac_header > skb->headroom, cause skb_push panic Use correct mac_offset to restore mac_header and get rid of nhoff. Fixes: c411ed854584 ("nsh: add GSO support") Reported-by: syzbot+632b5d9964208bfef8c0@syzkaller.appspotmail.com Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Dong Chenchen <dongchenchen2@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-14SUNRPC: Fix trace_svc_register() call siteChuck Lever
The trace event recorded incorrect values for the registered family, protocol, and port because the arguments are in the wrong order. Fixes: b4af59328c25 ("SUNRPC: Trace server-side rpcbind registration events") Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-05-14SUNRPC: always free ctxt when freeing deferred requestNeilBrown
Since the ->xprt_ctxt pointer was added to svc_deferred_req, it has not been sufficient to use kfree() to free a deferred request. We may need to free the ctxt as well. As freeing the ctxt is all that ->xpo_release_rqst() does, we repurpose it to explicit do that even when the ctxt is not stored in an rqst. So we now have ->xpo_release_ctxt() which is given an xprt and a ctxt, which may have been taken either from an rqst or from a dreq. The caller is now responsible for clearing that pointer after the call to ->xpo_release_ctxt. We also clear dr->xprt_ctxt when the ctxt is moved into a new rqst when revisiting a deferred request. This ensures there is only one pointer to the ctxt, so the risk of double freeing in future is reduced. The new code in svc_xprt_release which releases both the ctxt and any rq_deferred depends on this. Fixes: 773f91b2cf3f ("SUNRPC: Fix NFSD's request deferral on RDMA transports") Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-05-14SUNRPC: double free xprt_ctxt while still in useNeilBrown
When an RPC request is deferred, the rq_xprt_ctxt pointer is moved out of the svc_rqst into the svc_deferred_req. When the deferred request is revisited, the pointer is copied into the new svc_rqst - and also remains in the svc_deferred_req. In the (rare?) case that the request is deferred a second time, the old svc_deferred_req is reused - it still has all the correct content. However in that case the rq_xprt_ctxt pointer is NOT cleared so that when xpo_release_xprt is called, the ctxt is freed (UDP) or possible added to a free list (RDMA). When the deferred request is revisited for a second time, it will reference this ctxt which may be invalid, and the free the object a second time which is likely to oops. So change svc_defer() to *always* clear rq_xprt_ctxt, and assert that the value is now stored in the svc_deferred_req. Fixes: 773f91b2cf3f ("SUNRPC: Fix NFSD's request deferral on RDMA transports") Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2023-05-13ping: Convert hlist_nulls to plain hlist.Kuniyuki Iwashima
Since introduced in commit c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind"), ping socket does not use SLAB_TYPESAFE_BY_RCU nor check nulls marker in loops. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-13net: introduce and use skb_frag_fill_page_desc()Yunsheng Lin
Most users use __skb_frag_set_page()/skb_frag_off_set()/ skb_frag_size_set() to fill the page desc for a skb frag. Introduce skb_frag_fill_page_desc() to do that. net/bpf/test_run.c does not call skb_frag_off_set() to set the offset, "copy_from_user(page_address(page), ...)" and 'shinfo' being part of the 'data' kzalloced in bpf_test_init() suggest that it is assuming offset to be initialized as zero, so call skb_frag_fill_page_desc() with offset being zero for this case. Also, skb_frag_set_page() is not used anymore, so remove it. Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com> Reviewed-by: Leon Romanovsky <leonro@nvidia.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-13erspan: get the proto with the md version for collect_mdXin Long
In commit 20704bd1633d ("erspan: build the header with the right proto according to erspan_ver"), it gets the proto with t->parms.erspan_ver, but t->parms.erspan_ver is not used by collect_md branch, and instead it should get the proto with md->version for collect_md. Thanks to Kevin for pointing this out. Fixes: 20704bd1633d ("erspan: build the header with the right proto according to erspan_ver") Fixes: 94d7d8f29287 ("ip6_gre: add erspan v2 support") Reported-by: Kevin Traynor <ktraynor@redhat.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Reviewed-by: William Tu <u9012063@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-12sctp: add bpf_bypass_getsockopt proto callbackAlexander Mikhalitsyn
Implement ->bpf_bypass_getsockopt proto callback and filter out SCTP_SOCKOPT_PEELOFF, SCTP_SOCKOPT_PEELOFF_FLAGS and SCTP_SOCKOPT_CONNECTX3 socket options from running eBPF hook on them. SCTP_SOCKOPT_PEELOFF and SCTP_SOCKOPT_PEELOFF_FLAGS options do fd_install(), and if BPF_CGROUP_RUN_PROG_GETSOCKOPT hook returns an error after success of the original handler sctp_getsockopt(...), userspace will receive an error from getsockopt syscall and will be not aware that fd was successfully installed into a fdtable. As pointed by Marcelo Ricardo Leitner it seems reasonable to skip bpf getsockopt hook for SCTP_SOCKOPT_CONNECTX3 sockopt too. Because internaly, it triggers connect() and if error is masked then userspace will be confused. This patch was born as a result of discussion around a new SCM_PIDFD interface: https://lore.kernel.org/all/20230413133355.350571-3-aleksandr.mikhalitsyn@canonical.com/ Fixes: 0d01da6afc54 ("bpf: implement getsockopt and setsockopt hooks") Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Christian Brauner <brauner@kernel.org> Cc: Stanislav Fomichev <sdf@google.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Cc: Xin Long <lucien.xin@gmail.com> Cc: linux-sctp@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: netdev@vger.kernel.org Suggested-by: Stanislav Fomichev <sdf@google.com> Acked-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> Acked-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-12tcp: fix possible sk_priority leak in tcp_v4_send_reset()Eric Dumazet
When tcp_v4_send_reset() is called with @sk == NULL, we do not change ctl_sk->sk_priority, which could have been set from a prior invocation. Change tcp_v4_send_reset() to set sk_priority and sk_mark fields before calling ip_send_unicast_reply(). This means tcp_v4_send_reset() and tcp_v4_send_ack() no longer have to clear ctl_sk->sk_mark after their call to ip_send_unicast_reply(). Fixes: f6c0f5d209fa ("tcp: honor SO_PRIORITY in TIME_WAIT state") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Antoine Tenart <atenart@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-12vsock: avoid to close connected socket after the timeoutZhuang Shengen
When client and server establish a connection through vsock, the client send a request to the server to initiate the connection, then start a timer to wait for the server's response. When the server's RESPONSE message arrives, the timer also times out and exits. The server's RESPONSE message is processed first, and the connection is established. However, the client's timer also times out, the original processing logic of the client is to directly set the state of this vsock to CLOSE and return ETIMEDOUT. It will not notify the server when the port is released, causing the server port remain. when client's vsock_connect timeout,it should check sk state is ESTABLISHED or not. if sk state is ESTABLISHED, it means the connection is established, the client should not set the sk state to CLOSE Note: I encountered this issue on kernel-4.18, which can be fixed by this patch. Then I checked the latest code in the community and found similar issue. Fixes: d021c344051a ("VSOCK: Introduce VM Sockets") Signed-off-by: Zhuang Shengen <zhuangshengen@huawei.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-12net/handshake: Enable the SNI extension to work properlyChuck Lever
Enable the upper layer protocol to specify the SNI peername. This avoids the need for tlshd to use a DNS lookup, which can return a hostname that doesn't match the incoming certificate's SubjectName. Fixes: 2fd5532044a8 ("net/handshake: Add a kernel API for requesting a TLSv1.3 handshake") Reviewed-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-12net/handshake: Unpin sock->file if a handshake is cancelledChuck Lever
If user space never calls DONE, sock->file's reference count remains elevated. Enable sock->file to be freed eventually in this case. Reported-by: Jakub Kacinski <kuba@kernel.org> Fixes: 3b3009ea8abb ("net/handshake: Create a NETLINK service for handling handshake requests") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-12net/handshake: handshake_genl_notify() shouldn't ignore @flagsChuck Lever
Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Fixes: 3b3009ea8abb ("net/handshake: Create a NETLINK service for handling handshake requests") Reviewed-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-12net/handshake: Fix uninitialized local variableChuck Lever
trace_handshake_cmd_done_err() simply records the pointer in @req, so initializing it to NULL is sufficient and safe. Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Fixes: 3b3009ea8abb ("net/handshake: Create a NETLINK service for handling handshake requests") Reviewed-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-12net/handshake: Fix handshake_dup() ref countingChuck Lever
If get_unused_fd_flags() fails, we ended up calling fput(sock->file) twice. Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Suggested-by: Paolo Abeni <pabeni@redhat.com> Fixes: 3b3009ea8abb ("net/handshake: Create a NETLINK service for handling handshake requests") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-12net/handshake: Remove unneeded check from handshake_dup()Chuck Lever
handshake_req_submit() now verifies that the socket has a file. Fixes: 3b3009ea8abb ("net/handshake: Create a NETLINK service for handling handshake requests") Reviewed-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-11ipv6: remove nexthop_fib6_nh_bh()Eric Dumazet
After blamed commit, nexthop_fib6_nh_bh() and nexthop_fib6_nh() are the same. Delete nexthop_fib6_nh_bh(), and convert /proc/net/ipv6_route to standard rcu to avoid this splat: [ 5723.180080] WARNING: suspicious RCU usage [ 5723.180083] ----------------------------- [ 5723.180084] include/net/nexthop.h:516 suspicious rcu_dereference_check() usage! [ 5723.180086] other info that might help us debug this: [ 5723.180087] rcu_scheduler_active = 2, debug_locks = 1 [ 5723.180089] 2 locks held by cat/55856: [ 5723.180091] #0: ffff9440a582afa8 (&p->lock){+.+.}-{3:3}, at: seq_read_iter (fs/seq_file.c:188) [ 5723.180100] #1: ffffffffaac07040 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire (include/linux/rcupdate.h:326) [ 5723.180109] stack backtrace: [ 5723.180111] CPU: 14 PID: 55856 Comm: cat Tainted: G S I 6.3.0-dbx-DEV #528 [ 5723.180115] Call Trace: [ 5723.180117] <TASK> [ 5723.180119] dump_stack_lvl (lib/dump_stack.c:107) [ 5723.180124] dump_stack (lib/dump_stack.c:114) [ 5723.180126] lockdep_rcu_suspicious (include/linux/context_tracking.h:122) [ 5723.180132] ipv6_route_seq_show (include/net/nexthop.h:?) [ 5723.180135] ? ipv6_route_seq_next (net/ipv6/ip6_fib.c:2605) [ 5723.180140] seq_read_iter (fs/seq_file.c:272) [ 5723.180145] seq_read (fs/seq_file.c:163) [ 5723.180151] proc_reg_read (fs/proc/inode.c:316 fs/proc/inode.c:328) [ 5723.180155] vfs_read (fs/read_write.c:468) [ 5723.180160] ? up_read (kernel/locking/rwsem.c:1617) [ 5723.180164] ksys_read (fs/read_write.c:613) [ 5723.180168] __x64_sys_read (fs/read_write.c:621) [ 5723.180170] do_syscall_64 (arch/x86/entry/common.c:?) [ 5723.180174] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) [ 5723.180177] RIP: 0033:0x7fa455677d2a Fixes: 09eed1192cec ("neighbour: switch to standard rcu, instead of rcu_bh") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20230510154646.370659-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-11devlink: change per-devlink netdev notifier to static oneJiri Pirko
The commit 565b4824c39f ("devlink: change port event netdev notifier from per-net to global") changed original per-net notifier to be per-devlink instance. That fixed the issue of non-receiving events of netdev uninit if that moved to a different namespace. That worked fine in -net tree. However, later on when commit ee75f1fc44dd ("net/mlx5e: Create separate devlink instance for ethernet auxiliary device") and commit 72ed5d5624af ("net/mlx5: Suspend auxiliary devices only in case of PCI device suspend") were merged, a deadlock was introduced when removing a namespace with devlink instance with another nested instance. Here there is the bad flow example resulting in deadlock with mlx5: net_cleanup_work -> cleanup_net (takes down_read(&pernet_ops_rwsem) -> devlink_pernet_pre_exit() -> devlink_reload() -> mlx5_devlink_reload_down() -> mlx5_unload_one_devl_locked() -> mlx5_detach_device() -> del_adev() -> mlx5e_remove() -> mlx5e_destroy_devlink() -> devlink_free() -> unregister_netdevice_notifier() (takes down_write(&pernet_ops_rwsem) Steps to reproduce: $ modprobe mlx5_core $ ip netns add ns1 $ devlink dev reload pci/0000:08:00.0 netns ns1 $ ip netns del ns1 Resolve this by converting the notifier from per-devlink instance to a static one registered during init phase and leaving it registered forever. Use this notifier for all devlink port instances created later on. Note what a tree needs this fix only in case all of the cited fixes commits are present. Reported-by: Moshe Shemesh <moshe@nvidia.com> Fixes: 565b4824c39f ("devlink: change port event netdev notifier from per-net to global") Fixes: ee75f1fc44dd ("net/mlx5e: Create separate devlink instance for ethernet auxiliary device") Fixes: 72ed5d5624af ("net/mlx5: Suspend auxiliary devices only in case of PCI device suspend") Signed-off-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Link: https://lore.kernel.org/r/20230510144621.932017-1-jiri@resnulli.us Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes. No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-11tcp: make the first N SYN RTO backoffs linearDavid Morley
Currently the SYN RTO schedule follows an exponential backoff scheme, which can be unnecessarily conservative in cases where there are link failures. In such cases, it's better to aggressively try to retransmit packets, so it takes routers less time to find a repath with a working link. We chose a default value for this sysctl of 4, to follow the macOS and IOS backoff scheme of 1,1,1,1,1,2,4,8, ... MacOS and IOS have used this backoff schedule for over a decade, since before this 2009 IETF presentation discussed the behavior: https://www.ietf.org/proceedings/75/slides/tcpm-1.pdf This commit makes the SYN RTO schedule start with a number of linear backoffs given by the following sysctl: * tcp_syn_linear_timeouts This changes the SYN RTO scheme to be: init_rto_val for tcp_syn_linear_timeouts, exp backoff starting at init_rto_val For example if init_rto_val = 1 and tcp_syn_linear_timeouts = 2, our backoff scheme would be: 1, 1, 1, 2, 4, 8, 16, ... Signed-off-by: David Morley <morleyd@google.com> Signed-off-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Tested-by: David Morley <morleyd@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20230509180558.2541885-1-morleyd.kernel@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-05-10Merge tag 'nf-23-05-10' of ↵Jakub Kicinski
git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf Pablo Neira Ayuso says: ==================== Netfilter updates for net The following patchset contains Netfilter fixes for net: 1) Fix UAF when releasing netnamespace, from Florian Westphal. 2) Fix possible BUG_ON when nf_conntrack is enabled with enable_hooks, from Florian Westphal. 3) Fixes for nft_flowtable.sh selftest, from Boris Sukholitko. 4) Extend nft_flowtable.sh selftest to cover integration with ingress/egress hooks, from Florian Westphal. * tag 'nf-23-05-10' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf: selftests: nft_flowtable.sh: check ingress/egress chain too selftests: nft_flowtable.sh: monitor result file sizes selftests: nft_flowtable.sh: wait for specific nc pids selftests: nft_flowtable.sh: no need for ps -x option selftests: nft_flowtable.sh: use /proc for pid checking netfilter: conntrack: fix possible bug_on with enable_hooks=1 netfilter: nf_tables: always release netdev hooks from notifier ==================== Link: https://lore.kernel.org/r/20230510083313.152961-1-pablo@netfilter.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-10af_unix: Fix data races around sk->sk_shutdown.Kuniyuki Iwashima
KCSAN found a data race around sk->sk_shutdown where unix_release_sock() and unix_shutdown() update it under unix_state_lock(), OTOH unix_poll() and unix_dgram_poll() read it locklessly. We need to annotate the writes and reads with WRITE_ONCE() and READ_ONCE(). BUG: KCSAN: data-race in unix_poll / unix_release_sock write to 0xffff88800d0f8aec of 1 bytes by task 264 on cpu 0: unix_release_sock+0x75c/0x910 net/unix/af_unix.c:631 unix_release+0x59/0x80 net/unix/af_unix.c:1042 __sock_release+0x7d/0x170 net/socket.c:653 sock_close+0x19/0x30 net/socket.c:1397 __fput+0x179/0x5e0 fs/file_table.c:321 ____fput+0x15/0x20 fs/file_table.c:349 task_work_run+0x116/0x1a0 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x174/0x180 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:297 do_syscall_64+0x4b/0x90 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x72/0xdc read to 0xffff88800d0f8aec of 1 bytes by task 222 on cpu 1: unix_poll+0xa3/0x2a0 net/unix/af_unix.c:3170 sock_poll+0xcf/0x2b0 net/socket.c:1385 vfs_poll include/linux/poll.h:88 [inline] ep_item_poll.isra.0+0x78/0xc0 fs/eventpoll.c:855 ep_send_events fs/eventpoll.c:1694 [inline] ep_poll fs/eventpoll.c:1823 [inline] do_epoll_wait+0x6c4/0xea0 fs/eventpoll.c:2258 __do_sys_epoll_wait fs/eventpoll.c:2270 [inline] __se_sys_epoll_wait fs/eventpoll.c:2265 [inline] __x64_sys_epoll_wait+0xcc/0x190 fs/eventpoll.c:2265 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x72/0xdc value changed: 0x00 -> 0x03 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 222 Comm: dbus-broker Not tainted 6.3.0-rc7-02330-gca6270c12e20 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Fixes: 3c73419c09a5 ("af_unix: fix 'poll for write'/ connected DGRAM sockets") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Michal Kubiak <michal.kubiak@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-10af_unix: Fix a data race of sk->sk_receive_queue->qlen.Kuniyuki Iwashima
KCSAN found a data race of sk->sk_receive_queue->qlen where recvmsg() updates qlen under the queue lock and sendmsg() checks qlen under unix_state_sock(), not the queue lock, so the reader side needs READ_ONCE(). BUG: KCSAN: data-race in __skb_try_recv_from_queue / unix_wait_for_peer write (marked) to 0xffff888019fe7c68 of 4 bytes by task 49792 on cpu 0: __skb_unlink include/linux/skbuff.h:2347 [inline] __skb_try_recv_from_queue+0x3de/0x470 net/core/datagram.c:197 __skb_try_recv_datagram+0xf7/0x390 net/core/datagram.c:263 __unix_dgram_recvmsg+0x109/0x8a0 net/unix/af_unix.c:2452 unix_dgram_recvmsg+0x94/0xa0 net/unix/af_unix.c:2549 sock_recvmsg_nosec net/socket.c:1019 [inline] ____sys_recvmsg+0x3a3/0x3b0 net/socket.c:2720 ___sys_recvmsg+0xc8/0x150 net/socket.c:2764 do_recvmmsg+0x182/0x560 net/socket.c:2858 __sys_recvmmsg net/socket.c:2937 [inline] __do_sys_recvmmsg net/socket.c:2960 [inline] __se_sys_recvmmsg net/socket.c:2953 [inline] __x64_sys_recvmmsg+0x153/0x170 net/socket.c:2953 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x72/0xdc read to 0xffff888019fe7c68 of 4 bytes by task 49793 on cpu 1: skb_queue_len include/linux/skbuff.h:2127 [inline] unix_recvq_full net/unix/af_unix.c:229 [inline] unix_wait_for_peer+0x154/0x1a0 net/unix/af_unix.c:1445 unix_dgram_sendmsg+0x13bc/0x14b0 net/unix/af_unix.c:2048 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg+0x148/0x160 net/socket.c:747 ____sys_sendmsg+0x20e/0x620 net/socket.c:2503 ___sys_sendmsg+0xc6/0x140 net/socket.c:2557 __sys_sendmmsg+0x11d/0x370 net/socket.c:2643 __do_sys_sendmmsg net/socket.c:2672 [inline] __se_sys_sendmmsg net/socket.c:2669 [inline] __x64_sys_sendmmsg+0x58/0x70 net/socket.c:2669 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x72/0xdc value changed: 0x0000000b -> 0x00000001 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 49793 Comm: syz-executor.0 Not tainted 6.3.0-rc7-02330-gca6270c12e20 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Michal Kubiak <michal.kubiak@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-10net: datagram: fix data-races in datagram_poll()Eric Dumazet
datagram_poll() runs locklessly, we should add READ_ONCE() annotations while reading sk->sk_err, sk->sk_shutdown and sk->sk_state. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20230509173131.3263780-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-10sctp: fix a potential OOB access in sctp_sched_set_sched()Ilia.Gavrilov
The 'sched' index value must be checked before accessing an element of the 'sctp_sched_ops' array. Otherwise, it can lead to OOB access. Note that it's harmless since the 'sched' parameter is checked before calling 'sctp_sched_set_sched'. Found by InfoTeCS on behalf of Linux Verification Center (linuxtesting.org) with SVACE. Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: Ilia.Gavrilov <Ilia.Gavrilov@infotecs.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-10tcp: add annotations around sk->sk_shutdown accessesEric Dumazet
Now sk->sk_shutdown is no longer a bitfield, we can add standard READ_ONCE()/WRITE_ONCE() annotations to silence KCSAN reports like the following: BUG: KCSAN: data-race in tcp_disconnect / tcp_poll write to 0xffff88814588582c of 1 bytes by task 3404 on cpu 1: tcp_disconnect+0x4d6/0xdb0 net/ipv4/tcp.c:3121 __inet_stream_connect+0x5dd/0x6e0 net/ipv4/af_inet.c:715 inet_stream_connect+0x48/0x70 net/ipv4/af_inet.c:727 __sys_connect_file net/socket.c:2001 [inline] __sys_connect+0x19b/0x1b0 net/socket.c:2018 __do_sys_connect net/socket.c:2028 [inline] __se_sys_connect net/socket.c:2025 [inline] __x64_sys_connect+0x41/0x50 net/socket.c:2025 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffff88814588582c of 1 bytes by task 3374 on cpu 0: tcp_poll+0x2e6/0x7d0 net/ipv4/tcp.c:562 sock_poll+0x253/0x270 net/socket.c:1383 vfs_poll include/linux/poll.h:88 [inline] io_poll_check_events io_uring/poll.c:281 [inline] io_poll_task_func+0x15a/0x820 io_uring/poll.c:333 handle_tw_list io_uring/io_uring.c:1184 [inline] tctx_task_work+0x1fe/0x4d0 io_uring/io_uring.c:1246 task_work_run+0x123/0x160 kernel/task_work.c:179 get_signal+0xe64/0xff0 kernel/signal.c:2635 arch_do_signal_or_restart+0x89/0x2a0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop+0x6f/0xe0 kernel/entry/common.c:168 exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:297 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x03 -> 0x00 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-10net: add vlan_get_protocol_and_depth() helperEric Dumazet
Before blamed commit, pskb_may_pull() was used instead of skb_header_pointer() in __vlan_get_protocol() and friends. Few callers depended on skb->head being populated with MAC header, syzbot caught one of them (skb_mac_gso_segment()) Add vlan_get_protocol_and_depth() to make the intent clearer and use it where sensible. This is a more generic fix than commit e9d3f80935b6 ("net/af_packet: make sure to pull mac header") which was dealing with a similar issue. kernel BUG at include/linux/skbuff.h:2655 ! invalid opcode: 0000 [#1] SMP KASAN CPU: 0 PID: 1441 Comm: syz-executor199 Not tainted 6.1.24-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 RIP: 0010:__skb_pull include/linux/skbuff.h:2655 [inline] RIP: 0010:skb_mac_gso_segment+0x68f/0x6a0 net/core/gro.c:136 Code: fd 48 8b 5c 24 10 44 89 6b 70 48 c7 c7 c0 ae 0d 86 44 89 e6 e8 a1 91 d0 00 48 c7 c7 00 af 0d 86 48 89 de 31 d2 e8 d1 4a e9 ff <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 RSP: 0018:ffffc90001bd7520 EFLAGS: 00010286 RAX: ffffffff8469736a RBX: ffff88810f31dac0 RCX: ffff888115a18b00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90001bd75e8 R08: ffffffff84697183 R09: fffff5200037adf9 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000012 R13: 000000000000fee5 R14: 0000000000005865 R15: 000000000000fed7 FS: 000055555633f300(0000) GS:ffff8881f6a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000000 CR3: 0000000116fea000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> [<ffffffff847018dd>] __skb_gso_segment+0x32d/0x4c0 net/core/dev.c:3419 [<ffffffff8470398a>] skb_gso_segment include/linux/netdevice.h:4819 [inline] [<ffffffff8470398a>] validate_xmit_skb+0x3aa/0xee0 net/core/dev.c:3725 [<ffffffff84707042>] __dev_queue_xmit+0x1332/0x3300 net/core/dev.c:4313 [<ffffffff851a9ec7>] dev_queue_xmit+0x17/0x20 include/linux/netdevice.h:3029 [<ffffffff851b4a82>] packet_snd net/packet/af_packet.c:3111 [inline] [<ffffffff851b4a82>] packet_sendmsg+0x49d2/0x6470 net/packet/af_packet.c:3142 [<ffffffff84669a12>] sock_sendmsg_nosec net/socket.c:716 [inline] [<ffffffff84669a12>] sock_sendmsg net/socket.c:736 [inline] [<ffffffff84669a12>] __sys_sendto+0x472/0x5f0 net/socket.c:2139 [<ffffffff84669c75>] __do_sys_sendto net/socket.c:2151 [inline] [<ffffffff84669c75>] __se_sys_sendto net/socket.c:2147 [inline] [<ffffffff84669c75>] __x64_sys_sendto+0xe5/0x100 net/socket.c:2147 [<ffffffff8551d40f>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<ffffffff8551d40f>] do_syscall_64+0x2f/0x50 arch/x86/entry/common.c:80 [<ffffffff85600087>] entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: 469aceddfa3e ("vlan: consolidate VLAN parsing code and limit max parsing depth") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Toke Høiland-Jørgensen <toke@redhat.com> Cc: Willem de Bruijn <willemb@google.com> Reviewed-by: Simon Horman <simon.horman@corigine.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-10net: deal with most data-races in sk_wait_event()Eric Dumazet
__condition is evaluated twice in sk_wait_event() macro. First invocation is lockless, and reads can race with writes, as spotted by syzbot. BUG: KCSAN: data-race in sk_stream_wait_connect / tcp_disconnect write to 0xffff88812d83d6a0 of 4 bytes by task 9065 on cpu 1: tcp_disconnect+0x2cd/0xdb0 inet_shutdown+0x19e/0x1f0 net/ipv4/af_inet.c:911 __sys_shutdown_sock net/socket.c:2343 [inline] __sys_shutdown net/socket.c:2355 [inline] __do_sys_shutdown net/socket.c:2363 [inline] __se_sys_shutdown+0xf8/0x140 net/socket.c:2361 __x64_sys_shutdown+0x31/0x40 net/socket.c:2361 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffff88812d83d6a0 of 4 bytes by task 9040 on cpu 0: sk_stream_wait_connect+0x1de/0x3a0 net/core/stream.c:75 tcp_sendmsg_locked+0x2e4/0x2120 net/ipv4/tcp.c:1266 tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1484 inet6_sendmsg+0x63/0x80 net/ipv6/af_inet6.c:651 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] __sys_sendto+0x246/0x300 net/socket.c:2142 __do_sys_sendto net/socket.c:2154 [inline] __se_sys_sendto net/socket.c:2150 [inline] __x64_sys_sendto+0x78/0x90 net/socket.c:2150 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x00000000 -> 0x00000068 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-10net: annotate sk->sk_err write from do_recvmmsg()Eric Dumazet
do_recvmmsg() can write to sk->sk_err from multiple threads. As said before, many other points reading or writing sk_err need annotations. Fixes: 34b88a68f26a ("net: Fix use after free in the recvmmsg exit path") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-10netlink: annotate accesses to nlk->cb_runningEric Dumazet
Both netlink_recvmsg() and netlink_native_seq_show() read nlk->cb_running locklessly. Use READ_ONCE() there. Add corresponding WRITE_ONCE() to netlink_dump() and __netlink_dump_start() syzbot reported: BUG: KCSAN: data-race in __netlink_dump_start / netlink_recvmsg write to 0xffff88813ea4db59 of 1 bytes by task 28219 on cpu 0: __netlink_dump_start+0x3af/0x4d0 net/netlink/af_netlink.c:2399 netlink_dump_start include/linux/netlink.h:308 [inline] rtnetlink_rcv_msg+0x70f/0x8c0 net/core/rtnetlink.c:6130 netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2577 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6192 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline] netlink_unicast+0x56f/0x640 net/netlink/af_netlink.c:1365 netlink_sendmsg+0x665/0x770 net/netlink/af_netlink.c:1942 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] sock_write_iter+0x1aa/0x230 net/socket.c:1138 call_write_iter include/linux/fs.h:1851 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x463/0x760 fs/read_write.c:584 ksys_write+0xeb/0x1a0 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x42/0x50 fs/read_write.c:646 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd read to 0xffff88813ea4db59 of 1 bytes by task 28222 on cpu 1: netlink_recvmsg+0x3b4/0x730 net/netlink/af_netlink.c:2022 sock_recvmsg_nosec+0x4c/0x80 net/socket.c:1017 ____sys_recvmsg+0x2db/0x310 net/socket.c:2718 ___sys_recvmsg net/socket.c:2762 [inline] do_recvmmsg+0x2e5/0x710 net/socket.c:2856 __sys_recvmmsg net/socket.c:2935 [inline] __do_sys_recvmmsg net/socket.c:2958 [inline] __se_sys_recvmmsg net/socket.c:2951 [inline] __x64_sys_recvmmsg+0xe2/0x160 net/socket.c:2951 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x00 -> 0x01 Fixes: 16b304f3404f ("netlink: Eliminate kmalloc in netlink dump operation.") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-05-10net: ipconfig: Allow DNS to be overwritten by DHCPACKMartin Wetterwald
Some DHCP server implementations only send the important requested DHCP options in the final BOOTP reply (DHCPACK). One example is systemd-networkd. However, RFC2131, in section 4.3.1 states: > The server MUST return to the client: > [...] > o Parameters requested by the client, according to the following > rules: > > -- IF the server has been explicitly configured with a default > value for the parameter, the server MUST include that value > in an appropriate option in the 'option' field, ELSE I've reported the issue here: https://github.com/systemd/systemd/issues/27471 Linux PNP DHCP client implementation only takes into account the DNS servers received in the first BOOTP reply (DHCPOFFER). This usually isn't an issue as servers are required to put the same values in the DHCPOFFER and DHCPACK. However, RFC2131, in section 4.3.2 states: > Any configuration parameters in the DHCPACK message SHOULD NOT > conflict with those in the earlier DHCPOFFER message to which the > client is responding. The client SHOULD use the parameters in the > DHCPACK message for configuration. When making Linux PNP DHCP client (cmdline ip=dhcp) interact with systemd-networkd DHCP server, an interesting "protocol misunderstanding" happens: Because DNS servers were only specified in the DHCPACK and not in the DHCPOFFER, Linux will not catch the correct DNS servers: in the first BOOTP reply (DHCPOFFER), it sees that there is no DNS, and sets as fallback the IP of the DHCP server itself. When the second BOOTP reply comes (DHCPACK), it's already too late: the kernel will not overwrite the fallback setting it has set previously. This patch makes the kernel overwrite its DNS fallback by DNS servers specified in the DHCPACK if any. Signed-off-by: Martin Wetterwald <martin@wetterwald.eu> Signed-off-by: David S. Miller <davem@davemloft.net>