bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) ================================================================== BUG: KCSAN: data-race in wq_worker_tick / wq_worker_tick read-write to 0xffff8881000c5cd8 of 8 bytes by interrupt on cpu 1: wq_worker_tick+0x64/0x240 kernel/workqueue.c:1508 sched_tick+0xbc/0x1f0 kernel/sched/core.c:5804 update_process_times+0x15e/0x190 kernel/time/timer.c:2480 tick_sched_handle kernel/time/tick-sched.c:296 [inline] tick_nohz_handler+0x227/0x380 kernel/time/tick-sched.c:317 __run_hrtimer kernel/time/hrtimer.c:2032 [inline] __hrtimer_run_queues+0x1f8/0x510 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x257/0x810 kernel/time/hrtimer.c:2215 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x5f/0x1c0 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x32/0x80 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 skb_postpull_rcsum include/linux/skbuff.h:4067 [inline] skb_pull_rcsum+0xf2/0x220 net/core/skbuff.c:4651 nf_bridge_pull_encap_header_rcsum net/bridge/br_netfilter_hooks.c:197 [inline] br_nf_pre_routing+0x54d/0xc00 net/bridge/br_netfilter_hooks.c:512 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0x83b/0xa40 net/bridge/br_input.c:442 __netif_receive_skb_core+0x5b1/0x1950 net/core/dev.c:6093 __netif_receive_skb_one_core net/core/dev.c:6204 [inline] __netif_receive_skb net/core/dev.c:6319 [inline] process_backlog+0x25d/0x680 net/core/dev.c:6670 __napi_poll+0x61/0x300 net/core/dev.c:7729 napi_poll net/core/dev.c:7792 [inline] net_rx_action+0x456/0x930 net/core/dev.c:7949 handle_softirqs+0xb9/0x280 kernel/softirq.c:622 do_softirq+0x45/0x60 kernel/softirq.c:523 __local_bh_enable_ip+0x70/0x80 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] __alloc_skb+0x6b1/0x6f0 net/core/skbuff.c:699 alloc_skb include/linux/skbuff.h:1384 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:819 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline] nsim_dev_trap_report_work+0x18b/0x630 drivers/net/netdevsim/dev.c:922 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0x4d4/0x9a0 kernel/workqueue.c:3405 worker_thread+0x569/0x750 kernel/workqueue.c:3486 kthread+0x221/0x270 kernel/kthread.c:436 ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 read-write to 0xffff8881000c5cd8 of 8 bytes by interrupt on cpu 0: wq_worker_tick+0x64/0x240 kernel/workqueue.c:1508 sched_tick+0xbc/0x1f0 kernel/sched/core.c:5804 update_process_times+0x15e/0x190 kernel/time/timer.c:2480 tick_sched_handle kernel/time/tick-sched.c:296 [inline] tick_nohz_handler+0x227/0x380 kernel/time/tick-sched.c:317 __run_hrtimer kernel/time/hrtimer.c:2032 [inline] __hrtimer_run_queues+0x1f8/0x510 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x257/0x810 kernel/time/hrtimer.c:2215 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x5f/0x1c0 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x32/0x80 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 should_watch kernel/kcsan/core.c:280 [inline] check_access kernel/kcsan/core.c:752 [inline] __tsan_read8+0x117/0x190 kernel/kcsan/core.c:1025 net_generic include/net/netns/generic.h:47 [inline] is_vlan_arp net/bridge/br_netfilter_hooks.c:110 [inline] br_nf_forward_finish+0x124/0x780 net/bridge/br_netfilter_hooks.c:644 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_forward_ip+0x5fa/0x610 net/bridge/br_netfilter_hooks.c:721 br_nf_forward+0x5ba/0xee0 net/bridge/br_netfilter_hooks.c:778 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0x78/0x180 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK include/linux/netfilter.h:316 [inline] __br_forward+0x282/0x360 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver net/bridge/br_forward.c:191 [inline] br_flood+0x4de/0x760 net/bridge/br_forward.c:245 br_handle_frame_finish+0xaa3/0xdf0 net/bridge/br_input.c:229 br_nf_hook_thresh+0x233/0x270 net/bridge/br_netfilter_hooks.c:-1 br_nf_pre_routing_finish_ipv6+0x503/0x530 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x1fa/0x2e0 net/bridge/br_netfilter_ipv6.c:183 br_nf_pre_routing+0x577/0xc00 net/bridge/br_netfilter_hooks.c:513 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0x83b/0xa40 net/bridge/br_input.c:442 __netif_receive_skb_core+0x5b1/0x1950 net/core/dev.c:6093 __netif_receive_skb_one_core net/core/dev.c:6204 [inline] __netif_receive_skb net/core/dev.c:6319 [inline] process_backlog+0x25d/0x680 net/core/dev.c:6670 __napi_poll+0x61/0x300 net/core/dev.c:7729 napi_poll net/core/dev.c:7792 [inline] net_rx_action+0x456/0x930 net/core/dev.c:7949 handle_softirqs+0xb9/0x280 kernel/softirq.c:622 do_softirq+0x45/0x60 kernel/softirq.c:523 __local_bh_enable_ip+0x70/0x80 kernel/softirq.c:450 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:196 [inline] _raw_spin_unlock_bh+0x18/0x20 kernel/locking/spinlock.c:214 spin_unlock_bh include/linux/spinlock.h:396 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:891 [inline] nsim_dev_trap_report_work+0x521/0x630 drivers/net/netdevsim/dev.c:922 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0x4d4/0x9a0 kernel/workqueue.c:3405 worker_thread+0x569/0x750 kernel/workqueue.c:3486 kthread+0x221/0x270 kernel/kthread.c:436 ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 value changed: 0x0000000006cd5540 -> 0x0000000006cd7c50 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 15692 Comm: kworker/u8:14 Tainted: G W syzkaller #0 PREEMPT(lazy) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: events_unbound nsim_dev_trap_report_work ================================================================== net_ratelimit: 79343 callbacks suppressed bridge0: received packet on veth1_to_bridge with own address as source address (addr:a2:89:b0:1e:7b:d5, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) net_ratelimit: 85038 callbacks suppressed bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_1 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth1_to_bridge with own address as source address (addr:a2:89:b0:1e:7b:d5, vlan:0)