================================================================== BUG: KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv read-write to 0xffff88811e12ef80 of 4 bytes by interrupt on cpu 0: can_can_gw_rcv+0x812/0x820 net/can/gw.c:572 deliver net/can/af_can.c:575 [inline] can_rcv_filter+0xc3/0x480 net/can/af_can.c:602 can_receive+0x13e/0x190 net/can/af_can.c:674 can_rcv+0x17d/0x1f0 net/can/af_can.c:699 __netif_receive_skb_one_core net/core/dev.c:6206 [inline] __netif_receive_skb net/core/dev.c:6319 [inline] process_backlog+0x354/0x680 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] rt6_uncached_list_add net/ipv6/route.c:146 [inline] icmp6_dst_alloc+0x2d8/0x340 net/ipv6/route.c:3364 mld_sendpack+0x337/0x7c0 net/ipv6/mcast.c:1842 mld_send_cr net/ipv6/mcast.c:2154 [inline] mld_ifc_work+0x55a/0x840 net/ipv6/mcast.c:2694 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 0xffff88811e12ef80 of 4 bytes by interrupt on cpu 1: can_can_gw_rcv+0x812/0x820 net/can/gw.c:572 deliver net/can/af_can.c:575 [inline] can_rcv_filter+0xc3/0x480 net/can/af_can.c:602 can_receive+0x13e/0x190 net/can/af_can.c:674 can_rcv+0x17d/0x1f0 net/can/af_can.c:699 __netif_receive_skb_one_core net/core/dev.c:6206 [inline] __netif_receive_skb net/core/dev.c:6319 [inline] process_backlog+0x354/0x680 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 kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x42/0xd0 kernel/softirq.c:735 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x74/0x80 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:95 [inline] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] _raw_spin_unlock_irqrestore+0x1a/0x30 kernel/locking/spinlock.c:198 spin_unlock_irqrestore include/linux/spinlock.h:408 [inline] __skb_try_recv_datagram+0xd0/0x2b0 net/core/datagram.c:267 __unix_dgram_recvmsg+0x257/0x860 net/unix/af_unix.c:2582 unix_dgram_recvmsg+0x7e/0x90 net/unix/af_unix.c:2681 sock_recvmsg_nosec+0xc2/0xf0 net/socket.c:1126 ____sys_recvmsg+0x26f/0x280 net/socket.c:2902 ___sys_recvmsg+0x11f/0x3a0 net/socket.c:2946 do_recvmmsg+0x1e5/0x560 net/socket.c:3041 __sys_recvmmsg net/socket.c:3115 [inline] __do_sys_recvmmsg net/socket.c:3138 [inline] __se_sys_recvmmsg net/socket.c:3131 [inline] __x64_sys_recvmmsg+0xe5/0x170 net/socket.c:3131 x64_sys_call+0x80f/0x3020 arch/x86/include/generated/asm/syscalls_64.h:300 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f value changed: 0x00008ab8 -> 0x00008ab9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 6824 Comm: syz.2.1031 Not tainted syzkaller #0 PREEMPT(lazy) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 ================================================================== ================================================================== BUG: KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv read-write to 0xffff88811e12ef80 of 4 bytes by interrupt on cpu 0: can_can_gw_rcv+0x812/0x820 net/can/gw.c:572 deliver net/can/af_can.c:575 [inline] can_rcv_filter+0xc3/0x480 net/can/af_can.c:602 can_receive+0x13e/0x190 net/can/af_can.c:674 can_rcv+0x17d/0x1f0 net/can/af_can.c:699 __netif_receive_skb_one_core net/core/dev.c:6206 [inline] __netif_receive_skb net/core/dev.c:6319 [inline] process_backlog+0x354/0x680 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:1386 [inline] mld_newpack+0xa7/0x510 net/ipv6/mcast.c:1773 add_grhead net/ipv6/mcast.c:1884 [inline] add_grec+0xa39/0xc00 net/ipv6/mcast.c:2023 mld_send_cr net/ipv6/mcast.c:2148 [inline] mld_ifc_work+0x503/0x840 net/ipv6/mcast.c:2694 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 0xffff88811e12ef80 of 4 bytes by interrupt on cpu 1: can_can_gw_rcv+0x812/0x820 net/can/gw.c:572 deliver net/can/af_can.c:575 [inline] can_rcv_filter+0xc3/0x480 net/can/af_can.c:602 can_receive+0x13e/0x190 net/can/af_can.c:674 can_rcv+0x17d/0x1f0 net/can/af_can.c:699 __netif_receive_skb_one_core net/core/dev.c:6206 [inline] __netif_receive_skb net/core/dev.c:6319 [inline] process_backlog+0x354/0x680 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:1386 [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 value changed: 0x000d5add -> 0x000d5ade Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 54 Comm: kworker/u8:4 Not tainted syzkaller #0 PREEMPT(lazy) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: events_unbound nsim_dev_trap_report_work ==================================================================