bridge0: received packet on veth0_to_bridge with own address as source address (addr:42:d9:6b:74:f0:f9, vlan:0) ================================================================== BUG: KCSAN: data-race in wq_worker_tick / wq_worker_tick read-write to 0xffff8881000c5ed8 of 8 bytes by interrupt on cpu 0: wq_worker_tick+0x64/0x240 kernel/workqueue.c:1493 sched_tick+0xda/0x210 kernel/sched/core.c:5588 update_process_times+0x15e/0x190 kernel/time/timer.c:2479 tick_sched_handle kernel/time/tick-sched.c:298 [inline] tick_nohz_handler+0x275/0x3d0 kernel/time/tick-sched.c:319 __run_hrtimer kernel/time/hrtimer.c:1785 [inline] __hrtimer_run_queues+0x218/0x4f0 kernel/time/hrtimer.c:1849 hrtimer_interrupt+0x269/0x810 kernel/time/hrtimer.c:1911 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x5f/0x1f0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0x32/0x80 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 preempt_count arch/x86/include/asm/preempt.h:27 [inline] get_ctx kernel/kcsan/core.c:206 [inline] check_access kernel/kcsan/core.c:750 [inline] __tsan_read8+0xbe/0x190 kernel/kcsan/core.c:1025 skb_nfct include/linux/skbuff.h:4962 [inline] ipv6_defrag+0x26/0x260 net/ipv6/netfilter/nf_defrag_ipv6_hooks.c:60 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0x78/0x180 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK include/linux/netfilter.h:316 [inline] ipv6_rcv+0x12f/0x170 net/ipv6/ip6_input.c:311 __netif_receive_skb_one_core net/core/dev.c:6181 [inline] __netif_receive_skb net/core/dev.c:6294 [inline] process_backlog+0x2a5/0x670 net/core/dev.c:6645 __napi_poll+0x61/0x330 net/core/dev.c:7709 napi_poll net/core/dev.c:7772 [inline] net_rx_action+0x452/0x930 net/core/dev.c:7929 handle_softirqs+0xb9/0x2a0 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+0x658/0x690 net/core/skbuff.c:697 alloc_skb include/linux/skbuff.h:1383 [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+0x18a/0x630 drivers/net/netdevsim/dev.c:922 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0x513/0xa10 kernel/workqueue.c:3359 worker_thread+0x58a/0x780 kernel/workqueue.c:3440 kthread+0x22a/0x280 kernel/kthread.c:436 ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 read-write to 0xffff8881000c5ed8 of 8 bytes by interrupt on cpu 1: wq_worker_tick+0x64/0x240 kernel/workqueue.c:1493 sched_tick+0xda/0x210 kernel/sched/core.c:5588 update_process_times+0x15e/0x190 kernel/time/timer.c:2479 tick_sched_handle kernel/time/tick-sched.c:298 [inline] tick_nohz_handler+0x275/0x3d0 kernel/time/tick-sched.c:319 __run_hrtimer kernel/time/hrtimer.c:1785 [inline] __hrtimer_run_queues+0x218/0x4f0 kernel/time/hrtimer.c:1849 hrtimer_interrupt+0x269/0x810 kernel/time/hrtimer.c:1911 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x5f/0x1f0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0x32/0x80 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 preempt_count arch/x86/include/asm/preempt.h:27 [inline] get_ctx kernel/kcsan/core.c:206 [inline] check_access kernel/kcsan/core.c:750 [inline] __tsan_read1+0xba/0x180 kernel/kcsan/core.c:1022 selinux_parse_skb_ipv6 security/selinux/hooks.c:-1 [inline] selinux_parse_skb+0x1bf/0xba0 security/selinux/hooks.c:4682 selinux_ip_forward+0x26f/0x500 security/selinux/hooks.c:5877 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0x78/0x180 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK include/linux/netfilter.h:316 [inline] br_nf_forward_ip+0x5c8/0x620 net/bridge/br_netfilter_hooks.c:716 br_nf_forward+0x5a2/0xec0 net/bridge/br_netfilter_hooks.c:773 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0x78/0x180 net/netfilter/core.c:623 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+0x451/0x6d0 net/bridge/br_forward.c:238 br_handle_frame_finish+0xdd2/0xff0 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+0x550/0x580 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:184 br_nf_pre_routing+0x56a/0xbe0 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:291 [inline] br_handle_frame+0x85f/0xa60 net/bridge/br_input.c:442 __netif_receive_skb_core+0x5b1/0x1980 net/core/dev.c:6068 __netif_receive_skb_one_core net/core/dev.c:6179 [inline] __netif_receive_skb net/core/dev.c:6294 [inline] process_backlog+0x25b/0x670 net/core/dev.c:6645 __napi_poll+0x61/0x330 net/core/dev.c:7709 napi_poll net/core/dev.c:7772 [inline] net_rx_action+0x452/0x930 net/core/dev.c:7929 handle_softirqs+0xb9/0x2a0 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+0x658/0x690 net/core/skbuff.c:697 alloc_skb include/linux/skbuff.h:1383 [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+0x18a/0x630 drivers/net/netdevsim/dev.c:922 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0x513/0xa10 kernel/workqueue.c:3359 worker_thread+0x58a/0x780 kernel/workqueue.c:3440 kthread+0x22a/0x280 kernel/kthread.c:436 ret_from_fork+0x150/0x360 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 value changed: 0x00000000009bcad0 -> 0x00000000009bf1e0 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 18415 Comm: kworker/u8:11 Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: events_unbound nsim_dev_trap_report_work ================================================================== bridge0: received packet on veth0_to_bridge with own address as source address (addr:42:d9:6b:74:f0:f9, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:42:d9:6b:74:f0:f9, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:42:d9:6b:74:f0:f9, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:42:d9:6b:74:f0:f9, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:42:d9:6b:74:f0:f9, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:42:d9:6b:74:f0:f9, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:42:d9:6b:74:f0:f9, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:42:d9:6b:74:f0:f9, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:42:d9:6b:74:f0:f9, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:42:d9:6b:74:f0:f9, vlan:0)