[moderation] [can?] KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv (6)
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syzbot
Oct 20, 2026, 9:24:40 PM (24 hours ago) Oct 20
to syzkaller-upst...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 4cbdd58dfa7a Merge tag 'perf-core-2026-10-18' of git://git..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12a42831580000
kernel config: https://syzkaller.appspot.com/x/.config?x=5bcb9f6dd9a9fcf8
dashboard link: https://syzkaller.appspot.com/bug?extid=a6205fafcbfe69a5fd67
compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8
CC: [linu...@vger.kernel.org linux-...@vger.kernel.org m...@pengutronix.de sock...@hartkopp.net]
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/97c4fcf130fa/disk-4cbdd58d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/250292e90399/vmlinux-4cbdd58d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/75bee3bc2fa8/bzImage-4cbdd58d.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a6205f...@syzkaller.appspotmail.com
IN= OUT=eth0 SRC=10.128.1.152 DST=10.128.0.163 LEN=52 TOS=0x00 PREC=0x00 TTL=64 ID=48410 DF PROTO=TCP SPT=43180 DPT=30036 WINDOW=2872 RES=0x00 ACK URGP=0
==================================================================
BUG: KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
read-write to 0xffff88811ca21620 of 4 bytes by interrupt on cpu 1:
can_can_gw_rcv+0x858/0x860 net/can/gw.c:575
deliver net/can/af_can.c:575 [inline]
can_rcv_filter+0xc3/0x480 net/can/af_can.c:602
can_receive+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
__do_softirq kernel/softirq.c:679 [inline]
invoke_softirq kernel/softirq.c:519 [inline]
__irq_exit_rcu+0x44/0xe0 kernel/softirq.c:758
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
constant_test_bit arch/x86/include/asm/bitops.h:202 [inline]
arch_test_bit arch/x86/include/asm/bitops.h:232 [inline]
_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline]
folio_test_swapbacked include/linux/page-flags.h:572 [inline]
mm_counter_file include/linux/mm.h:3489 [inline]
mm_counter include/linux/mm.h:3498 [inline]
zap_present_folio_ptes mm/memory.c:1789 [inline]
zap_present_ptes mm/memory.c:1861 [inline]
do_zap_pte_range mm/memory.c:1963 [inline]
zap_pte_range mm/memory.c:2065 [inline]
zap_pmd_range mm/memory.c:2151 [inline]
zap_pud_range mm/memory.c:2179 [inline]
zap_p4d_range mm/memory.c:2200 [inline]
__zap_vma_range+0x144c/0x2c50 mm/memory.c:2240
unmap_vmas+0x1fb/0x2e0 mm/memory.c:2309
exit_mmap+0x1a2/0x5e0 mm/mmap.c:1315
__mmput+0x28/0x1c0 kernel/fork.c:1193
mmput+0x3b/0x50 kernel/fork.c:1216
exit_mm+0x11b/0x1b0 kernel/exit.c:592
do_exit+0x445/0x14f0 kernel/exit.c:974
do_group_exit+0xfe/0x140 kernel/exit.c:1130
get_signal+0xe02/0xf00 kernel/signal.c:3112
arch_do_signal_or_restart+0x96/0x480 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x15d/0x8c0 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
do_syscall_64+0x212/0x360 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
read-write to 0xffff88811ca21620 of 4 bytes by interrupt on cpu 0:
can_can_gw_rcv+0x858/0x860 net/can/gw.c:575
deliver net/can/af_can.c:575 [inline]
can_rcv_filter+0xc3/0x480 net/can/af_can.c:602
can_receive+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
__do_softirq kernel/softirq.c:679 [inline]
invoke_softirq kernel/softirq.c:519 [inline]
__irq_exit_rcu+0x44/0xe0 kernel/softirq.c:758
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
kcsan_setup_watchpoint+0x42b/0x4a0 kernel/kcsan/core.c:713
io_nop+0x21f/0x2c0 io_uring/nop.c:-1
__io_issue_sqe+0xfd/0x2e0 io_uring/io_uring.c:1388
io_issue_sqe+0x1e7/0xb80 io_uring/io_uring.c:1411
io_queue_sqe io_uring/io_uring.c:1642 [inline]
io_submit_sqe io_uring/io_uring.c:1927 [inline]
io_submit_sqes+0x7e1/0x1180 io_uring/io_uring.c:2050
__do_sys_io_uring_enter io_uring/io_uring.c:2640 [inline]
__se_sys_io_uring_enter+0x25c/0xf90 io_uring/io_uring.c:2589
__x64_sys_io_uring_enter+0x78/0x90 io_uring/io_uring.c:2589
x64_sys_call+0x1780/0x2550 arch/x86/include/generated/asm/syscalls_64.h:427
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
value changed: 0x000015b6 -> 0x000015b7
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 18058 Comm: syz.1.6046 Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
==================================================================
IN= OUT=eth0 SRC=10.128.1.152 DST=10.128.0.163 LEN=52 TOS=0x00 PREC=0x00 TTL=64 ID=48411 DF PROTO=TCP SPT=43180 DPT=30036 WINDOW=2872 RES=0x00 ACK URGP=0
ip6_tunnel: ip6gretap0: Local routing loop detected!
==================================================================
BUG: KCSAN: data-race in vxcan_xmit / vxcan_xmit
read-write to 0xffff88811b0b8230 of 8 bytes by interrupt on cpu 1:
vxcan_xmit+0x2d0/0x380 drivers/net/can/vxcan.c:91
__netdev_start_xmit include/linux/netdevice.h:5432 [inline]
netdev_start_xmit include/linux/netdevice.h:5441 [inline]
xmit_one net/core/dev.c:3953 [inline]
dev_hard_start_xmit+0x10c/0x380 net/core/dev.c:3969
__dev_queue_xmit+0xbfd/0x1ec0 net/core/dev.c:4958
dev_queue_xmit include/linux/netdevice.h:3464 [inline]
can_send+0x584/0x720 net/can/af_can.c:279
can_can_gw_rcv+0x80c/0x860 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+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
__do_softirq kernel/softirq.c:679 [inline]
invoke_softirq kernel/softirq.c:519 [inline]
__irq_exit_rcu+0x44/0xe0 kernel/softirq.c:758
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:123 [inline]
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:211 [inline]
_raw_spin_unlock_irqrestore+0x1a/0x30 kernel/locking/spinlock.c:221
spin_unlock_irqrestore include/linux/spinlock.h:425 [inline]
__uart_port_unlock_irqrestore include/linux/serial_core.h:622 [inline]
univ8250_console_device_unlock+0x36/0x40 drivers/tty/serial/8250/8250_core.c:420
nbcon_emit_one kernel/printk/nbcon.c:1165 [inline]
nbcon_kthread_func+0x5e0/0x6d0 kernel/printk/nbcon.c:1271
kthread+0x223/0x270 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 0xffff88811b0b8230 of 8 bytes by interrupt on cpu 0:
vxcan_xmit+0x2d0/0x380 drivers/net/can/vxcan.c:91
__netdev_start_xmit include/linux/netdevice.h:5432 [inline]
netdev_start_xmit include/linux/netdevice.h:5441 [inline]
xmit_one net/core/dev.c:3953 [inline]
dev_hard_start_xmit+0x10c/0x380 net/core/dev.c:3969
__dev_queue_xmit+0xbfd/0x1ec0 net/core/dev.c:4958
dev_queue_xmit include/linux/netdevice.h:3464 [inline]
can_send+0x584/0x720 net/can/af_can.c:279
can_can_gw_rcv+0x80c/0x860 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+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
do_softirq+0x46/0x60 kernel/softirq.c:546
__local_bh_enable_ip+0x79/0x80 kernel/softirq.c:473
local_bh_enable include/linux/bottom_half.h:33 [inline]
__alloc_skb+0x6b6/0x6f0 net/core/skbuff.c:699
alloc_skb include/linux/skbuff.h:1384 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:744 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:801 [inline]
nsim_dev_trap_report_work+0x18b/0x620 drivers/net/netdevsim/dev.c:847
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0x53f/0xa10 kernel/workqueue.c:3479
worker_thread+0x569/0x750 kernel/workqueue.c:3560
kthread+0x223/0x270 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: 0x00000000000052ee -> 0x00000000000052ef
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 743 Comm: kworker/u8:11 Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Workqueue: events_unbound nsim_dev_trap_report_work
==================================================================
==================================================================
BUG: KCSAN: data-race in vxcan_xmit / vxcan_xmit
read-write to 0xffff88811b0b8230 of 8 bytes by interrupt on cpu 1:
vxcan_xmit+0x2d0/0x380 drivers/net/can/vxcan.c:91
__netdev_start_xmit include/linux/netdevice.h:5432 [inline]
netdev_start_xmit include/linux/netdevice.h:5441 [inline]
xmit_one net/core/dev.c:3953 [inline]
dev_hard_start_xmit+0x10c/0x380 net/core/dev.c:3969
__dev_queue_xmit+0xbfd/0x1ec0 net/core/dev.c:4958
dev_queue_xmit include/linux/netdevice.h:3464 [inline]
can_send+0x584/0x720 net/can/af_can.c:279
can_can_gw_rcv+0x80c/0x860 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+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
do_softirq+0x46/0x60 kernel/softirq.c:546
__local_bh_enable_ip+0x79/0x80 kernel/softirq.c:473
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:237 [inline]
_raw_spin_unlock_bh+0x17/0x20 kernel/locking/spinlock.c:245
spin_unlock_bh include/linux/spinlock.h:407 [inline]
neigh_periodic_work+0x5e2/0x690 net/core/neighbour.c:1035
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0x53f/0xa10 kernel/workqueue.c:3479
worker_thread+0x569/0x750 kernel/workqueue.c:3560
kthread+0x223/0x270 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 0xffff88811b0b8230 of 8 bytes by interrupt on cpu 0:
vxcan_xmit+0x2d0/0x380 drivers/net/can/vxcan.c:91
__netdev_start_xmit include/linux/netdevice.h:5432 [inline]
netdev_start_xmit include/linux/netdevice.h:5441 [inline]
xmit_one net/core/dev.c:3953 [inline]
dev_hard_start_xmit+0x10c/0x380 net/core/dev.c:3969
__dev_queue_xmit+0xbfd/0x1ec0 net/core/dev.c:4958
dev_queue_xmit include/linux/netdevice.h:3464 [inline]
can_send+0x584/0x720 net/can/af_can.c:279
can_can_gw_rcv+0x80c/0x860 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+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
run_ksoftirqd+0x1c/0x30 kernel/softirq.c:1099
smpboot_thread_fn+0x372/0x560 kernel/smpboot.c:162
kthread+0x223/0x270 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: 0x000000000004b746 -> 0x000000000004b747
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 14 Comm: ksoftirqd/0 Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
==================================================================
==================================================================
BUG: KCSAN: data-race in vxcan_xmit / vxcan_xmit
read-write to 0xffff88811b0c0228 of 8 bytes by interrupt on cpu 1:
vxcan_xmit+0x30d/0x380 drivers/net/can/vxcan.c:94
__netdev_start_xmit include/linux/netdevice.h:5432 [inline]
netdev_start_xmit include/linux/netdevice.h:5441 [inline]
xmit_one net/core/dev.c:3953 [inline]
dev_hard_start_xmit+0x10c/0x380 net/core/dev.c:3969
__dev_queue_xmit+0xbfd/0x1ec0 net/core/dev.c:4958
dev_queue_xmit include/linux/netdevice.h:3464 [inline]
can_send+0x584/0x720 net/can/af_can.c:279
can_can_gw_rcv+0x80c/0x860 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+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
do_softirq+0x46/0x60 kernel/softirq.c:546
__local_bh_enable_ip+0x79/0x80 kernel/softirq.c:473
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:237 [inline]
_raw_spin_unlock_bh+0x17/0x20 kernel/locking/spinlock.c:245
spin_unlock_bh include/linux/spinlock.h:407 [inline]
neigh_periodic_work+0x5e2/0x690 net/core/neighbour.c:1035
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0x53f/0xa10 kernel/workqueue.c:3479
worker_thread+0x569/0x750 kernel/workqueue.c:3560
kthread+0x223/0x270 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 0xffff88811b0c0228 of 8 bytes by interrupt on cpu 0:
vxcan_xmit+0x30d/0x380 drivers/net/can/vxcan.c:94
__netdev_start_xmit include/linux/netdevice.h:5432 [inline]
netdev_start_xmit include/linux/netdevice.h:5441 [inline]
xmit_one net/core/dev.c:3953 [inline]
dev_hard_start_xmit+0x10c/0x380 net/core/dev.c:3969
__dev_queue_xmit+0xbfd/0x1ec0 net/core/dev.c:4958
dev_queue_xmit include/linux/netdevice.h:3464 [inline]
can_send+0x584/0x720 net/can/af_can.c:279
can_can_gw_rcv+0x80c/0x860 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+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
run_ksoftirqd+0x1c/0x30 kernel/softirq.c:1099
smpboot_thread_fn+0x372/0x560 kernel/smpboot.c:162
kthread+0x223/0x270 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: 0x00000000000566f0 -> 0x00000000000566f1
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 14 Comm: ksoftirqd/0 Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
==================================================================
==================================================================
BUG: KCSAN: data-race in vxcan_xmit / vxcan_xmit
read-write to 0xffff88811b0c0228 of 8 bytes by interrupt on cpu 1:
vxcan_xmit+0x30d/0x380 drivers/net/can/vxcan.c:94
__netdev_start_xmit include/linux/netdevice.h:5432 [inline]
netdev_start_xmit include/linux/netdevice.h:5441 [inline]
xmit_one net/core/dev.c:3953 [inline]
dev_hard_start_xmit+0x10c/0x380 net/core/dev.c:3969
__dev_queue_xmit+0xbfd/0x1ec0 net/core/dev.c:4958
dev_queue_xmit include/linux/netdevice.h:3464 [inline]
can_send+0x584/0x720 net/can/af_can.c:279
can_can_gw_rcv+0x80c/0x860 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+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
do_softirq+0x46/0x60 kernel/softirq.c:546
__local_bh_enable_ip+0x79/0x80 kernel/softirq.c:473
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:237 [inline]
_raw_spin_unlock_bh+0x17/0x20 kernel/locking/spinlock.c:245
spin_unlock_bh include/linux/spinlock.h:407 [inline]
neigh_periodic_work+0x5e2/0x690 net/core/neighbour.c:1035
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0x53f/0xa10 kernel/workqueue.c:3479
worker_thread+0x569/0x750 kernel/workqueue.c:3560
kthread+0x223/0x270 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 0xffff88811b0c0228 of 8 bytes by interrupt on cpu 0:
vxcan_xmit+0x30d/0x380 drivers/net/can/vxcan.c:94
__netdev_start_xmit include/linux/netdevice.h:5432 [inline]
netdev_start_xmit include/linux/netdevice.h:5441 [inline]
xmit_one net/core/dev.c:3953 [inline]
dev_hard_start_xmit+0x10c/0x380 net/core/dev.c:3969
__dev_queue_xmit+0xbfd/0x1ec0 net/core/dev.c:4958
dev_queue_xmit include/linux/netdevice.h:3464 [inline]
can_send+0x584/0x720 net/can/af_can.c:279
can_can_gw_rcv+0x80c/0x860 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+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
do_softirq+0x46/0x60 kernel/softirq.c:546
__local_bh_enable_ip+0x79/0x80 kernel/softirq.c:473
local_bh_enable include/linux/bottom_half.h:33 [inline]
__alloc_skb+0x6b6/0x6f0 net/core/skbuff.c:699
alloc_skb include/linux/skbuff.h:1384 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:744 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:801 [inline]
nsim_dev_trap_report_work+0x18b/0x620 drivers/net/netdevsim/dev.c:847
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0x53f/0xa10 kernel/workqueue.c:3479
worker_thread+0x569/0x750 kernel/workqueue.c:3560
kthread+0x223/0x270 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: 0x00000000000a1884 -> 0x00000000000a1885
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 4193 Comm: kworker/u8:18 Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Workqueue: events_unbound nsim_dev_trap_report_work
==================================================================
==================================================================
BUG: KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
read-write to 0xffff88811ca21620 of 4 bytes by interrupt on cpu 1:
can_can_gw_rcv+0x858/0x860 net/can/gw.c:575
deliver net/can/af_can.c:575 [inline]
can_rcv_filter+0xc3/0x480 net/can/af_can.c:602
can_receive+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
do_softirq+0x46/0x60 kernel/softirq.c:546
__local_bh_enable_ip+0x79/0x80 kernel/softirq.c:473
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:237 [inline]
_raw_spin_unlock_bh+0x17/0x20 kernel/locking/spinlock.c:245
spin_unlock_bh include/linux/spinlock.h:407 [inline]
release_sock+0x10c/0x180 net/core/sock.c:3907
tcp_recvmsg+0x140/0x4b0 net/ipv4/tcp.c:2947
inet_recvmsg+0x8d/0x210 net/ipv4/af_inet.c:894
sock_recvmsg_nosec net/socket.c:1153 [inline]
sock_recvmsg+0xda/0x120 net/socket.c:1173
sock_read_iter+0x146/0x190 net/socket.c:1242
new_sync_read fs/read_write.c:493 [inline]
vfs_read+0x699/0x7c0 fs/read_write.c:574
ksys_read+0xdc/0x1a0 fs/read_write.c:716
__do_sys_read fs/read_write.c:725 [inline]
__se_sys_read fs/read_write.c:723 [inline]
__x64_sys_read+0x40/0x50 fs/read_write.c:723
x64_sys_call+0x2135/0x2550 arch/x86/include/generated/asm/syscalls_64.h:1
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
---
This report is generated by a bot. It may contain errors.
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#syz undup
syzbot found the following issue on:
HEAD commit: 4cbdd58dfa7a Merge tag 'perf-core-2026-10-18' of git://git..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12a42831580000
kernel config: https://syzkaller.appspot.com/x/.config?x=5bcb9f6dd9a9fcf8
dashboard link: https://syzkaller.appspot.com/bug?extid=a6205fafcbfe69a5fd67
compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8
CC: [linu...@vger.kernel.org linux-...@vger.kernel.org m...@pengutronix.de sock...@hartkopp.net]
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/97c4fcf130fa/disk-4cbdd58d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/250292e90399/vmlinux-4cbdd58d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/75bee3bc2fa8/bzImage-4cbdd58d.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a6205f...@syzkaller.appspotmail.com
IN= OUT=eth0 SRC=10.128.1.152 DST=10.128.0.163 LEN=52 TOS=0x00 PREC=0x00 TTL=64 ID=48410 DF PROTO=TCP SPT=43180 DPT=30036 WINDOW=2872 RES=0x00 ACK URGP=0
==================================================================
BUG: KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
read-write to 0xffff88811ca21620 of 4 bytes by interrupt on cpu 1:
can_can_gw_rcv+0x858/0x860 net/can/gw.c:575
deliver net/can/af_can.c:575 [inline]
can_rcv_filter+0xc3/0x480 net/can/af_can.c:602
can_receive+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
__do_softirq kernel/softirq.c:679 [inline]
invoke_softirq kernel/softirq.c:519 [inline]
__irq_exit_rcu+0x44/0xe0 kernel/softirq.c:758
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
constant_test_bit arch/x86/include/asm/bitops.h:202 [inline]
arch_test_bit arch/x86/include/asm/bitops.h:232 [inline]
_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline]
folio_test_swapbacked include/linux/page-flags.h:572 [inline]
mm_counter_file include/linux/mm.h:3489 [inline]
mm_counter include/linux/mm.h:3498 [inline]
zap_present_folio_ptes mm/memory.c:1789 [inline]
zap_present_ptes mm/memory.c:1861 [inline]
do_zap_pte_range mm/memory.c:1963 [inline]
zap_pte_range mm/memory.c:2065 [inline]
zap_pmd_range mm/memory.c:2151 [inline]
zap_pud_range mm/memory.c:2179 [inline]
zap_p4d_range mm/memory.c:2200 [inline]
__zap_vma_range+0x144c/0x2c50 mm/memory.c:2240
unmap_vmas+0x1fb/0x2e0 mm/memory.c:2309
exit_mmap+0x1a2/0x5e0 mm/mmap.c:1315
__mmput+0x28/0x1c0 kernel/fork.c:1193
mmput+0x3b/0x50 kernel/fork.c:1216
exit_mm+0x11b/0x1b0 kernel/exit.c:592
do_exit+0x445/0x14f0 kernel/exit.c:974
do_group_exit+0xfe/0x140 kernel/exit.c:1130
get_signal+0xe02/0xf00 kernel/signal.c:3112
arch_do_signal_or_restart+0x96/0x480 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x15d/0x8c0 kernel/entry/common.c:101
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
do_syscall_64+0x212/0x360 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
read-write to 0xffff88811ca21620 of 4 bytes by interrupt on cpu 0:
can_can_gw_rcv+0x858/0x860 net/can/gw.c:575
deliver net/can/af_can.c:575 [inline]
can_rcv_filter+0xc3/0x480 net/can/af_can.c:602
can_receive+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
__do_softirq kernel/softirq.c:679 [inline]
invoke_softirq kernel/softirq.c:519 [inline]
__irq_exit_rcu+0x44/0xe0 kernel/softirq.c:758
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
kcsan_setup_watchpoint+0x42b/0x4a0 kernel/kcsan/core.c:713
io_nop+0x21f/0x2c0 io_uring/nop.c:-1
__io_issue_sqe+0xfd/0x2e0 io_uring/io_uring.c:1388
io_issue_sqe+0x1e7/0xb80 io_uring/io_uring.c:1411
io_queue_sqe io_uring/io_uring.c:1642 [inline]
io_submit_sqe io_uring/io_uring.c:1927 [inline]
io_submit_sqes+0x7e1/0x1180 io_uring/io_uring.c:2050
__do_sys_io_uring_enter io_uring/io_uring.c:2640 [inline]
__se_sys_io_uring_enter+0x25c/0xf90 io_uring/io_uring.c:2589
__x64_sys_io_uring_enter+0x78/0x90 io_uring/io_uring.c:2589
x64_sys_call+0x1780/0x2550 arch/x86/include/generated/asm/syscalls_64.h:427
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
value changed: 0x000015b6 -> 0x000015b7
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 18058 Comm: syz.1.6046 Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
==================================================================
IN= OUT=eth0 SRC=10.128.1.152 DST=10.128.0.163 LEN=52 TOS=0x00 PREC=0x00 TTL=64 ID=48411 DF PROTO=TCP SPT=43180 DPT=30036 WINDOW=2872 RES=0x00 ACK URGP=0
ip6_tunnel: ip6gretap0: Local routing loop detected!
==================================================================
BUG: KCSAN: data-race in vxcan_xmit / vxcan_xmit
read-write to 0xffff88811b0b8230 of 8 bytes by interrupt on cpu 1:
vxcan_xmit+0x2d0/0x380 drivers/net/can/vxcan.c:91
__netdev_start_xmit include/linux/netdevice.h:5432 [inline]
netdev_start_xmit include/linux/netdevice.h:5441 [inline]
xmit_one net/core/dev.c:3953 [inline]
dev_hard_start_xmit+0x10c/0x380 net/core/dev.c:3969
__dev_queue_xmit+0xbfd/0x1ec0 net/core/dev.c:4958
dev_queue_xmit include/linux/netdevice.h:3464 [inline]
can_send+0x584/0x720 net/can/af_can.c:279
can_can_gw_rcv+0x80c/0x860 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+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
__do_softirq kernel/softirq.c:679 [inline]
invoke_softirq kernel/softirq.c:519 [inline]
__irq_exit_rcu+0x44/0xe0 kernel/softirq.c:758
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:123 [inline]
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:211 [inline]
_raw_spin_unlock_irqrestore+0x1a/0x30 kernel/locking/spinlock.c:221
spin_unlock_irqrestore include/linux/spinlock.h:425 [inline]
__uart_port_unlock_irqrestore include/linux/serial_core.h:622 [inline]
univ8250_console_device_unlock+0x36/0x40 drivers/tty/serial/8250/8250_core.c:420
nbcon_emit_one kernel/printk/nbcon.c:1165 [inline]
nbcon_kthread_func+0x5e0/0x6d0 kernel/printk/nbcon.c:1271
kthread+0x223/0x270 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 0xffff88811b0b8230 of 8 bytes by interrupt on cpu 0:
vxcan_xmit+0x2d0/0x380 drivers/net/can/vxcan.c:91
__netdev_start_xmit include/linux/netdevice.h:5432 [inline]
netdev_start_xmit include/linux/netdevice.h:5441 [inline]
xmit_one net/core/dev.c:3953 [inline]
dev_hard_start_xmit+0x10c/0x380 net/core/dev.c:3969
__dev_queue_xmit+0xbfd/0x1ec0 net/core/dev.c:4958
dev_queue_xmit include/linux/netdevice.h:3464 [inline]
can_send+0x584/0x720 net/can/af_can.c:279
can_can_gw_rcv+0x80c/0x860 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+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
do_softirq+0x46/0x60 kernel/softirq.c:546
__local_bh_enable_ip+0x79/0x80 kernel/softirq.c:473
local_bh_enable include/linux/bottom_half.h:33 [inline]
__alloc_skb+0x6b6/0x6f0 net/core/skbuff.c:699
alloc_skb include/linux/skbuff.h:1384 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:744 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:801 [inline]
nsim_dev_trap_report_work+0x18b/0x620 drivers/net/netdevsim/dev.c:847
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0x53f/0xa10 kernel/workqueue.c:3479
worker_thread+0x569/0x750 kernel/workqueue.c:3560
kthread+0x223/0x270 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: 0x00000000000052ee -> 0x00000000000052ef
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 743 Comm: kworker/u8:11 Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Workqueue: events_unbound nsim_dev_trap_report_work
==================================================================
==================================================================
BUG: KCSAN: data-race in vxcan_xmit / vxcan_xmit
read-write to 0xffff88811b0b8230 of 8 bytes by interrupt on cpu 1:
vxcan_xmit+0x2d0/0x380 drivers/net/can/vxcan.c:91
__netdev_start_xmit include/linux/netdevice.h:5432 [inline]
netdev_start_xmit include/linux/netdevice.h:5441 [inline]
xmit_one net/core/dev.c:3953 [inline]
dev_hard_start_xmit+0x10c/0x380 net/core/dev.c:3969
__dev_queue_xmit+0xbfd/0x1ec0 net/core/dev.c:4958
dev_queue_xmit include/linux/netdevice.h:3464 [inline]
can_send+0x584/0x720 net/can/af_can.c:279
can_can_gw_rcv+0x80c/0x860 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+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
do_softirq+0x46/0x60 kernel/softirq.c:546
__local_bh_enable_ip+0x79/0x80 kernel/softirq.c:473
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:237 [inline]
_raw_spin_unlock_bh+0x17/0x20 kernel/locking/spinlock.c:245
spin_unlock_bh include/linux/spinlock.h:407 [inline]
neigh_periodic_work+0x5e2/0x690 net/core/neighbour.c:1035
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0x53f/0xa10 kernel/workqueue.c:3479
worker_thread+0x569/0x750 kernel/workqueue.c:3560
kthread+0x223/0x270 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 0xffff88811b0b8230 of 8 bytes by interrupt on cpu 0:
vxcan_xmit+0x2d0/0x380 drivers/net/can/vxcan.c:91
__netdev_start_xmit include/linux/netdevice.h:5432 [inline]
netdev_start_xmit include/linux/netdevice.h:5441 [inline]
xmit_one net/core/dev.c:3953 [inline]
dev_hard_start_xmit+0x10c/0x380 net/core/dev.c:3969
__dev_queue_xmit+0xbfd/0x1ec0 net/core/dev.c:4958
dev_queue_xmit include/linux/netdevice.h:3464 [inline]
can_send+0x584/0x720 net/can/af_can.c:279
can_can_gw_rcv+0x80c/0x860 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+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
run_ksoftirqd+0x1c/0x30 kernel/softirq.c:1099
smpboot_thread_fn+0x372/0x560 kernel/smpboot.c:162
kthread+0x223/0x270 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: 0x000000000004b746 -> 0x000000000004b747
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 14 Comm: ksoftirqd/0 Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
==================================================================
==================================================================
BUG: KCSAN: data-race in vxcan_xmit / vxcan_xmit
read-write to 0xffff88811b0c0228 of 8 bytes by interrupt on cpu 1:
vxcan_xmit+0x30d/0x380 drivers/net/can/vxcan.c:94
__netdev_start_xmit include/linux/netdevice.h:5432 [inline]
netdev_start_xmit include/linux/netdevice.h:5441 [inline]
xmit_one net/core/dev.c:3953 [inline]
dev_hard_start_xmit+0x10c/0x380 net/core/dev.c:3969
__dev_queue_xmit+0xbfd/0x1ec0 net/core/dev.c:4958
dev_queue_xmit include/linux/netdevice.h:3464 [inline]
can_send+0x584/0x720 net/can/af_can.c:279
can_can_gw_rcv+0x80c/0x860 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+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
do_softirq+0x46/0x60 kernel/softirq.c:546
__local_bh_enable_ip+0x79/0x80 kernel/softirq.c:473
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:237 [inline]
_raw_spin_unlock_bh+0x17/0x20 kernel/locking/spinlock.c:245
spin_unlock_bh include/linux/spinlock.h:407 [inline]
neigh_periodic_work+0x5e2/0x690 net/core/neighbour.c:1035
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0x53f/0xa10 kernel/workqueue.c:3479
worker_thread+0x569/0x750 kernel/workqueue.c:3560
kthread+0x223/0x270 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 0xffff88811b0c0228 of 8 bytes by interrupt on cpu 0:
vxcan_xmit+0x30d/0x380 drivers/net/can/vxcan.c:94
__netdev_start_xmit include/linux/netdevice.h:5432 [inline]
netdev_start_xmit include/linux/netdevice.h:5441 [inline]
xmit_one net/core/dev.c:3953 [inline]
dev_hard_start_xmit+0x10c/0x380 net/core/dev.c:3969
__dev_queue_xmit+0xbfd/0x1ec0 net/core/dev.c:4958
dev_queue_xmit include/linux/netdevice.h:3464 [inline]
can_send+0x584/0x720 net/can/af_can.c:279
can_can_gw_rcv+0x80c/0x860 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+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
run_ksoftirqd+0x1c/0x30 kernel/softirq.c:1099
smpboot_thread_fn+0x372/0x560 kernel/smpboot.c:162
kthread+0x223/0x270 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: 0x00000000000566f0 -> 0x00000000000566f1
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 14 Comm: ksoftirqd/0 Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
==================================================================
==================================================================
BUG: KCSAN: data-race in vxcan_xmit / vxcan_xmit
read-write to 0xffff88811b0c0228 of 8 bytes by interrupt on cpu 1:
vxcan_xmit+0x30d/0x380 drivers/net/can/vxcan.c:94
__netdev_start_xmit include/linux/netdevice.h:5432 [inline]
netdev_start_xmit include/linux/netdevice.h:5441 [inline]
xmit_one net/core/dev.c:3953 [inline]
dev_hard_start_xmit+0x10c/0x380 net/core/dev.c:3969
__dev_queue_xmit+0xbfd/0x1ec0 net/core/dev.c:4958
dev_queue_xmit include/linux/netdevice.h:3464 [inline]
can_send+0x584/0x720 net/can/af_can.c:279
can_can_gw_rcv+0x80c/0x860 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+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
do_softirq+0x46/0x60 kernel/softirq.c:546
__local_bh_enable_ip+0x79/0x80 kernel/softirq.c:473
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:237 [inline]
_raw_spin_unlock_bh+0x17/0x20 kernel/locking/spinlock.c:245
spin_unlock_bh include/linux/spinlock.h:407 [inline]
neigh_periodic_work+0x5e2/0x690 net/core/neighbour.c:1035
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0x53f/0xa10 kernel/workqueue.c:3479
worker_thread+0x569/0x750 kernel/workqueue.c:3560
kthread+0x223/0x270 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 0xffff88811b0c0228 of 8 bytes by interrupt on cpu 0:
vxcan_xmit+0x30d/0x380 drivers/net/can/vxcan.c:94
__netdev_start_xmit include/linux/netdevice.h:5432 [inline]
netdev_start_xmit include/linux/netdevice.h:5441 [inline]
xmit_one net/core/dev.c:3953 [inline]
dev_hard_start_xmit+0x10c/0x380 net/core/dev.c:3969
__dev_queue_xmit+0xbfd/0x1ec0 net/core/dev.c:4958
dev_queue_xmit include/linux/netdevice.h:3464 [inline]
can_send+0x584/0x720 net/can/af_can.c:279
can_can_gw_rcv+0x80c/0x860 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+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
do_softirq+0x46/0x60 kernel/softirq.c:546
__local_bh_enable_ip+0x79/0x80 kernel/softirq.c:473
local_bh_enable include/linux/bottom_half.h:33 [inline]
__alloc_skb+0x6b6/0x6f0 net/core/skbuff.c:699
alloc_skb include/linux/skbuff.h:1384 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:744 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:801 [inline]
nsim_dev_trap_report_work+0x18b/0x620 drivers/net/netdevsim/dev.c:847
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0x53f/0xa10 kernel/workqueue.c:3479
worker_thread+0x569/0x750 kernel/workqueue.c:3560
kthread+0x223/0x270 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: 0x00000000000a1884 -> 0x00000000000a1885
Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 4193 Comm: kworker/u8:18 Not tainted syzkaller #0 PREEMPT(lazy)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Workqueue: events_unbound nsim_dev_trap_report_work
==================================================================
==================================================================
BUG: KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
read-write to 0xffff88811ca21620 of 4 bytes by interrupt on cpu 1:
can_can_gw_rcv+0x858/0x860 net/can/gw.c:575
deliver net/can/af_can.c:575 [inline]
can_rcv_filter+0xc3/0x480 net/can/af_can.c:602
can_receive+0xd2/0x120 net/can/af_can.c:669
canfd_rcv+0x1b6/0x270 net/can/af_can.c:730
__netif_receive_skb_one_core net/core/dev.c:6297 [inline]
__netif_receive_skb net/core/dev.c:6410 [inline]
process_backlog+0x354/0x680 net/core/dev.c:6761
__napi_poll+0x61/0x300 net/core/dev.c:7830
napi_poll net/core/dev.c:7893 [inline]
net_rx_action+0x456/0x930 net/core/dev.c:8050
handle_softirqs+0xcc/0x2a0 kernel/softirq.c:645
do_softirq+0x46/0x60 kernel/softirq.c:546
__local_bh_enable_ip+0x79/0x80 kernel/softirq.c:473
__raw_spin_unlock_bh include/linux/spinlock_api_smp.h:237 [inline]
_raw_spin_unlock_bh+0x17/0x20 kernel/locking/spinlock.c:245
spin_unlock_bh include/linux/spinlock.h:407 [inline]
release_sock+0x10c/0x180 net/core/sock.c:3907
tcp_recvmsg+0x140/0x4b0 net/ipv4/tcp.c:2947
inet_recvmsg+0x8d/0x210 net/ipv4/af_inet.c:894
sock_recvmsg_nosec net/socket.c:1153 [inline]
sock_recvmsg+0xda/0x120 net/socket.c:1173
sock_read_iter+0x146/0x190 net/socket.c:1242
new_sync_read fs/read_write.c:493 [inline]
vfs_read+0x699/0x7c0 fs/read_write.c:574
ksys_read+0xdc/0x1a0 fs/read_write.c:716
__do_sys_read fs/read_write.c:725 [inline]
__se_sys_read fs/read_write.c:723 [inline]
__x64_sys_read+0x40/0x50 fs/read_write.c:723
x64_sys_call+0x2135/0x2550 arch/x86/include/generated/asm/syscalls_64.h:1
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
---
This report is generated by a bot. It may contain errors.
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