================================================================== 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 fib_rule_match net/core/fib_rules.c:285 [inline] fib_rules_lookup+0xdd/0x7e0 net/core/fib_rules.c:323 __fib_lookup+0xb4/0x140 net/ipv4/fib_rules.c:96 fib_lookup include/net/ip_fib.h:382 [inline] __fib_validate_source net/ipv4/fib_frontend.c:380 [inline] fib_validate_source+0x56d/0xb00 net/ipv4/fib_frontend.c:459 fib_validate_source_reason include/net/ip_fib.h:462 [inline] ip_mc_validate_source net/ipv4/route.c:1732 [inline] ip_route_input_mc net/ipv4/route.c:1751 [inline] ip_route_input_rcu+0xb06/0x1c10 net/ipv4/route.c:2537 ip_route_input_noref+0x5f/0x90 net/ipv4/route.c:2554 ip_rcv_finish_core+0x312/0xb60 net/ipv4/ip_input.c:368 ip_rcv_finish+0x100/0x1a0 net/ipv4/ip_input.c:451 ip_sabotage_in+0x13f/0x160 net/bridge/br_netfilter_hooks.c:990 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] ip_rcv+0x11f/0x160 net/ipv4/ip_input.c:573 __netif_receive_skb_one_core net/core/dev.c:6181 [inline] __netif_receive_skb net/core/dev.c:6294 [inline] netif_receive_skb_internal net/core/dev.c:6380 [inline] netif_receive_skb+0x137/0x530 net/core/dev.c:6439 br_netif_receive_skb net/bridge/br_input.c:30 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] br_pass_frame_up+0x23b/0x330 net/bridge/br_input.c:70 br_handle_frame_finish+0xdf1/0xff0 net/bridge/br_input.c:-1 br_nf_hook_thresh net/bridge/br_netfilter_hooks.c:-1 [inline] br_nf_pre_routing_finish+0x8af/0xbe0 net/bridge/br_netfilter_hooks.c:425 rcu_read_unlock include/linux/rcupdate.h:883 [inline] nf_hook include/linux/netfilter.h:275 [inline] NF_HOOK+0x1ec/0x230 include/linux/netfilter.h:316 br_nf_pre_routing+0xaea/0xbe0 net/bridge/br_netfilter_hooks.c:534 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 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:196 [inline] _raw_spin_unlock_bh+0x18/0x20 kernel/locking/spinlock.c:210 spin_unlock_bh include/linux/spinlock.h:395 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:891 [inline] nsim_dev_trap_report_work+0x52b/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 write_comp_data kernel/kcov.c:270 [inline] __sanitizer_cov_trace_const_cmp1+0x82/0x90 kernel/kcov.c:300 __br_multicast_querier_exists net/bridge/br_private.h:1165 [inline] br_multicast_querier_exists net/bridge/br_private.h:1188 [inline] br_handle_frame_finish+0xb19/0xff0 net/bridge/br_input.c:190 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 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:196 [inline] _raw_spin_unlock_bh+0x18/0x20 kernel/locking/spinlock.c:210 spin_unlock_bh include/linux/spinlock.h:395 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:891 [inline] nsim_dev_trap_report_work+0x52b/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: 0x000000001301e010 -> 0x0000000013020720 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 20589 Comm: kworker/u8:2 Tainted: G W syzkaller #0 PREEMPT(full) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: events_unbound nsim_dev_trap_report_work ================================================================== audit: audit_backlog=65 > audit_backlog_limit=64 audit: audit_lost=91092 audit_rate_limit=0 audit_backlog_limit=64