syzbot


KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv (5)

Status: moderation: reported on 2025/12/15 04:17
Subsystems: can
Labels: prio:normal
[Documentation on labels]
Reported-by: syzbot+a34b5a7b2a9e0fa0cf77@syzkaller.appspotmail.com
First crash: 191d, last: 6h44m
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision Error
c1d111e8-0d6a-4f4d-a8b7-80d5ab20283d assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv (5) 2026/05/24 12:46 2026/05/24 12:46 2026/05/24 13:26 c69befb30ac10e158cc9d1557b508ee3f0eca1de

			
		
15b877cf-65aa-4ab6-aff6-801c328ece03 assessment-kcsan Benign: ✅ Confident: ✅ KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv (5) 2026/01/15 13:04 2026/01/15 13:04 2026/01/15 13:08 a9d6a79219801d2130df3b1a792c57f0e5428e9f

			
		
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv can 6 4 774d 819d 0/29 auto-obsoleted due to no activity on 2024/06/14 15:49
upstream KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv (4) can 6 9 290d 383d 0/29 auto-obsoleted due to no activity on 2025/11/02 07:50
upstream KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv (3) can 6 4 486d 471d 0/29 auto-obsoleted due to no activity on 2025/04/19 08:20
upstream KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv (2) can 6 1 596d 596d 0/29 auto-obsoleted due to no activity on 2024/12/30 16:15

Sample crash report:
==================================================================
BUG: KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv

read-write to 0xffff8881001753e0 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 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+0x37/0x80 arch/x86/kernel/apic/apic.c:1062
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674

read-write to 0xffff8881001753e0 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:1384 [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: 0x00ad1648 -> 0x00ad1649

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 22533 Comm: kworker/u8:36 Tainted: G        W           syzkaller #0 PREEMPT(lazy) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events_unbound nsim_dev_trap_report_work
==================================================================
ip6_tunnel: ip6tnl3 xmit: Local address not yet configured!

Crashes (36):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/24 01:31 upstream 558ef39aeb9a 042555ff .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/06/24 01:29 upstream 558ef39aeb9a 042555ff .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/06/17 23:43 upstream 66affa37cfac b62b3ded .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/06/13 00:10 upstream 1dadb7e7eb5a 1d2f3589 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/06/11 09:26 upstream 9716c086c8e8 b754d2d8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/06/02 04:11 upstream 6f3ed7fec72f 1095583b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/06/01 15:22 upstream e43ffb69e043 8d8eeb3a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/05/29 05:08 upstream 8fde5d1d47f6 4624854e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/05/12 22:54 upstream c21b90f77687 a0949470 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/05/08 02:16 upstream fcee7d82f27d 5633175a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/05/05 11:12 upstream a293ec25d59d 06e69a27 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/05/05 01:10 upstream c7e4e4d5f7dc a898ba9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/05/05 01:10 upstream c7e4e4d5f7dc a898ba9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/05/02 06:58 upstream 6fe0be6dc7fa 753c55b9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/05/01 05:41 upstream 26fd6bff2c05 753c55b9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/04/30 10:35 upstream e75a43c7cec4 005438fc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/04/30 10:34 upstream e75a43c7cec4 005438fc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/04/28 08:47 upstream 3b3bea6d4b9c ce741359 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/04/28 00:45 upstream 3b3bea6d4b9c ce741359 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/04/27 18:18 upstream 254f49634ee1 0f700595 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/04/24 14:32 upstream dd6c438c3e64 1c2b9291 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/04/21 21:43 upstream 4ee64205ffaa 0b6ab7ec .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/04/21 16:27 upstream b4e07588e743 0b6ab7ec .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/04/15 18:18 upstream 1f5ffc672165 c441f497 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/04/09 23:37 upstream 8b02520ec5f7 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/03/31 15:19 upstream d0c3bcd5b897 aeea1c72 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/02/24 23:52 upstream 7dff99b35460 787dfb7c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/02/21 11:31 upstream d79526b89571 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/02/20 12:09 upstream 8bf22c33e7a1 17d780d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/02/19 20:10 upstream 2b7a25df823d c8d8c52d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/02/08 18:46 upstream e98f34af6116 4c131dc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/01/26 13:03 upstream 63804fed149a a4c52dd6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/01/21 19:55 upstream cf38b2340c0e 8fc37797 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/01/21 15:41 upstream 6c790212c588 6f1aa2f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2026/01/20 16:01 upstream 24d479d26b25 06648d9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
2025/12/15 04:16 upstream 8f0b4cce4481 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in can_can_gw_rcv / can_can_gw_rcv
* Struck through repros no longer work on HEAD.