================================================================== BUG: KCSAN: data-race in br_handle_frame_finish / br_handle_frame_finish read-write to 0xffff88810384a178 of 8 bytes by interrupt on cpu 0: br_handle_frame_finish+0xd4f/0xef0 net/bridge/br_input.c:189 br_nf_hook_thresh+0x1ed/0x220 br_nf_pre_routing_finish_ipv6+0x50f/0x540 NF_HOOK include/linux/netfilter.h:303 [inline] br_nf_pre_routing_ipv6+0x1e3/0x2a0 net/bridge/br_netfilter_ipv6.c:178 br_nf_pre_routing+0x526/0xba0 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:143 [inline] nf_hook_bridge_pre net/bridge/br_input.c:272 [inline] br_handle_frame+0x4c7/0x8e0 net/bridge/br_input.c:416 __netif_receive_skb_core+0x9e8/0x1e80 net/core/dev.c:5385 __netif_receive_skb_one_core net/core/dev.c:5489 [inline] __netif_receive_skb+0x57/0x1b0 net/core/dev.c:5605 process_backlog+0x21f/0x380 net/core/dev.c:5933 __napi_poll+0x60/0x3b0 net/core/dev.c:6496 napi_poll net/core/dev.c:6563 [inline] net_rx_action+0x32b/0x750 net/core/dev.c:6696 __do_softirq+0xc1/0x265 kernel/softirq.c:571 run_ksoftirqd+0x17/0x20 kernel/softirq.c:939 smpboot_thread_fn+0x30a/0x4a0 kernel/smpboot.c:164 kthread+0x1d7/0x210 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 read-write to 0xffff88810384a178 of 8 bytes by interrupt on cpu 1: br_handle_frame_finish+0xd4f/0xef0 net/bridge/br_input.c:189 br_nf_hook_thresh+0x1ed/0x220 br_nf_pre_routing_finish_ipv6+0x50f/0x540 NF_HOOK include/linux/netfilter.h:303 [inline] br_nf_pre_routing_ipv6+0x1e3/0x2a0 net/bridge/br_netfilter_ipv6.c:178 br_nf_pre_routing+0x526/0xba0 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:143 [inline] nf_hook_bridge_pre net/bridge/br_input.c:272 [inline] br_handle_frame+0x4c7/0x8e0 net/bridge/br_input.c:416 __netif_receive_skb_core+0x9e8/0x1e80 net/core/dev.c:5385 __netif_receive_skb_one_core net/core/dev.c:5489 [inline] __netif_receive_skb+0x57/0x1b0 net/core/dev.c:5605 process_backlog+0x21f/0x380 net/core/dev.c:5933 __napi_poll+0x60/0x3b0 net/core/dev.c:6496 napi_poll net/core/dev.c:6563 [inline] net_rx_action+0x32b/0x750 net/core/dev.c:6696 __do_softirq+0xc1/0x265 kernel/softirq.c:571 do_softirq+0x7e/0xb0 kernel/softirq.c:472 __local_bh_enable_ip+0x64/0x70 kernel/softirq.c:396 local_bh_enable+0x1f/0x20 include/linux/bottom_half.h:33 rcu_read_unlock_bh include/linux/rcupdate.h:843 [inline] __dev_queue_xmit+0xabb/0x1d10 net/core/dev.c:4271 dev_queue_xmit include/linux/netdevice.h:3085 [inline] neigh_hh_output include/net/neighbour.h:528 [inline] neigh_output include/net/neighbour.h:542 [inline] ip_finish_output2+0x700/0x840 net/ipv4/ip_output.c:229 ip_finish_output+0xf4/0x240 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:292 [inline] ip_output+0xe5/0x1b0 net/ipv4/ip_output.c:431 dst_output include/net/dst.h:458 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] __ip_queue_xmit+0xa4d/0xa70 net/ipv4/ip_output.c:533 ip_queue_xmit+0x38/0x40 net/ipv4/ip_output.c:547 __tcp_transmit_skb+0x1194/0x16e0 net/ipv4/tcp_output.c:1399 tcp_transmit_skb net/ipv4/tcp_output.c:1417 [inline] tcp_write_xmit+0x13ff/0x2fd0 net/ipv4/tcp_output.c:2693 __tcp_push_pending_frames+0x6a/0x1a0 net/ipv4/tcp_output.c:2877 tcp_push+0x320/0x330 net/ipv4/tcp.c:733 tcp_sendmsg_locked+0x1cf8/0x2120 net/ipv4/tcp.c:1459 tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1487 inet_sendmsg+0x63/0x80 net/ipv4/af_inet.c:825 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg net/socket.c:747 [inline] sock_write_iter+0x1aa/0x230 net/socket.c:1140 call_write_iter include/linux/fs.h:1868 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x47b/0x780 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 value changed: 0x0000000000003984 -> 0x0000000000003985 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 3163 Comm: syz-fuzzer Not tainted 6.4.0-rc3-syzkaller-00291-g4e893b5aa4ac #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 ================================================================== ================================================================== BUG: KCSAN: data-race in br_handle_frame_finish / br_handle_frame_finish read-write to 0xffff88810384a178 of 8 bytes by interrupt on cpu 0: br_handle_frame_finish+0xd4f/0xef0 net/bridge/br_input.c:189 br_nf_hook_thresh+0x1ed/0x220 br_nf_pre_routing_finish_ipv6+0x50f/0x540 NF_HOOK include/linux/netfilter.h:303 [inline] br_nf_pre_routing_ipv6+0x1e3/0x2a0 net/bridge/br_netfilter_ipv6.c:178 br_nf_pre_routing+0x526/0xba0 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:143 [inline] nf_hook_bridge_pre net/bridge/br_input.c:272 [inline] br_handle_frame+0x4c7/0x8e0 net/bridge/br_input.c:416 __netif_receive_skb_core+0x9e8/0x1e80 net/core/dev.c:5385 __netif_receive_skb_one_core net/core/dev.c:5489 [inline] __netif_receive_skb+0x57/0x1b0 net/core/dev.c:5605 process_backlog+0x21f/0x380 net/core/dev.c:5933 __napi_poll+0x60/0x3b0 net/core/dev.c:6496 napi_poll net/core/dev.c:6563 [inline] net_rx_action+0x32b/0x750 net/core/dev.c:6696 __do_softirq+0xc1/0x265 kernel/softirq.c:571 run_ksoftirqd+0x17/0x20 kernel/softirq.c:939 smpboot_thread_fn+0x30a/0x4a0 kernel/smpboot.c:164 kthread+0x1d7/0x210 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 read-write to 0xffff88810384a178 of 8 bytes by interrupt on cpu 1: br_handle_frame_finish+0xd4f/0xef0 net/bridge/br_input.c:189 br_nf_hook_thresh+0x1ed/0x220 br_nf_pre_routing_finish_ipv6+0x50f/0x540 NF_HOOK include/linux/netfilter.h:303 [inline] br_nf_pre_routing_ipv6+0x1e3/0x2a0 net/bridge/br_netfilter_ipv6.c:178 br_nf_pre_routing+0x526/0xba0 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:143 [inline] nf_hook_bridge_pre net/bridge/br_input.c:272 [inline] br_handle_frame+0x4c7/0x8e0 net/bridge/br_input.c:416 __netif_receive_skb_core+0x9e8/0x1e80 net/core/dev.c:5385 __netif_receive_skb_one_core net/core/dev.c:5489 [inline] __netif_receive_skb+0x57/0x1b0 net/core/dev.c:5605 process_backlog+0x21f/0x380 net/core/dev.c:5933 __napi_poll+0x60/0x3b0 net/core/dev.c:6496 napi_poll net/core/dev.c:6563 [inline] net_rx_action+0x32b/0x750 net/core/dev.c:6696 __do_softirq+0xc1/0x265 kernel/softirq.c:571 run_ksoftirqd+0x17/0x20 kernel/softirq.c:939 smpboot_thread_fn+0x30a/0x4a0 kernel/smpboot.c:164 kthread+0x1d7/0x210 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 value changed: 0x0000000000014dcc -> 0x0000000000014dcd Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 19 Comm: ksoftirqd/1 Not tainted 6.4.0-rc3-syzkaller-00291-g4e893b5aa4ac #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 ==================================================================