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:aa:aa:aa:aa:aa:0c, 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 kcsan_setup_watchpoint+0x404/0x410 kernel/kcsan/core.c:705 qdisc_pkt_len_segs_init+0x7d/0x3c0 net/core/dev.c:4112 __dev_queue_xmit+0x18e/0x1f20 net/core/dev.c:4782 dev_queue_xmit include/linux/netdevice.h:3385 [inline] br_dev_queue_push_xmit+0x233/0x2a0 net/bridge/br_forward.c:53 NF_HOOK include/linux/netfilter.h:318 [inline] br_forward_finish+0x89/0x190 net/bridge/br_forward.c:66 NF_HOOK include/linux/netfilter.h:318 [inline] __br_forward+0x2b8/0x360 net/bridge/br_forward.c:115 br_flood+0x588/0x6d0 net/bridge/br_forward.c:-1 br_handle_frame_finish+0xdd2/0xff0 net/bridge/br_input.c:229 nf_hook_bridge_pre net/bridge/br_input.c:313 [inline] br_handle_frame+0x452/0xa60 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 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 is_atomic kernel/kcsan/core.c:249 [inline] should_watch kernel/kcsan/core.c:277 [inline] check_access kernel/kcsan/core.c:752 [inline] __tsan_read8+0xe8/0x190 kernel/kcsan/core.c:1025 skb_transport_header+0x47/0x80 include/linux/skbuff.h:3073 skb_transport_offset include/linux/skbuff.h:3223 [inline] ip6_multipath_l3_keys+0x188/0x250 net/ipv6/route.c:2371 rt6_multipath_hash+0x597/0xfb0 net/ipv6/route.c:-1 ip6_route_input+0x5e3/0x620 net/ipv6/route.c:2653 ip6_rcv_finish_core net/ipv6/ip6_input.c:66 [inline] ip6_rcv_finish+0x1be/0x330 net/ipv6/ip6_input.c:77 NF_HOOK include/linux/netfilter.h:318 [inline] ipv6_rcv+0x72/0x170 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] netif_receive_skb_internal net/core/dev.c:6380 [inline] netif_receive_skb+0xc5/0x530 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 nf_hook_bridge_pre net/bridge/br_input.c:313 [inline] br_handle_frame+0x452/0xa60 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: 0x00000000030306d0 -> 0x0000000003032de0 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 5730 Comm: kworker/u8:20 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Workqueue: events_unbound nsim_dev_trap_report_work ================================================================== net_ratelimit: 186805 callbacks suppressed 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 bridge_slave_1 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 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 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)