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KCSAN: data-race in isotp_sendmsg / isotp_sendmsg (8)

Status: moderation: reported on 2025/06/08 08:02
Subsystems: can
[Documentation on labels]
Reported-by: syzbot+22dd51a3caa6caf3dfc6@syzkaller.appspotmail.com
First crash: 3d19h, last: 3d19h
Similar bugs (7)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in isotp_sendmsg / isotp_sendmsg (6) can 2 388d 400d 0/28 auto-obsoleted due to no activity on 2024/06/23 13:44
upstream KCSAN: data-race in isotp_sendmsg / isotp_sendmsg (7) can 3 308d 332d 0/28 auto-obsoleted due to no activity on 2024/09/11 12:09
upstream KCSAN: data-race in isotp_sendmsg / isotp_sendmsg can 1 1308d 1308d 0/28 auto-closed as invalid on 2021/12/16 09:51
upstream KCSAN: data-race in isotp_sendmsg / isotp_sendmsg (5) can 3 581d 611d 0/28 auto-obsoleted due to no activity on 2023/12/13 23:05
upstream KCSAN: data-race in isotp_sendmsg / isotp_sendmsg (2) can 1 1186d 1186d 0/28 auto-closed as invalid on 2022/04/17 15:57
upstream KCSAN: data-race in isotp_sendmsg / isotp_sendmsg (4) can 1 675d 675d 0/28 auto-obsoleted due to no activity on 2023/09/10 09:53
upstream KCSAN: data-race in isotp_sendmsg / isotp_sendmsg (3) can 1 740d 740d 0/28 auto-obsoleted due to no activity on 2023/07/07 22:13

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

write to 0xffff888152db24b4 of 4 bytes by task 18892 on cpu 0:
 isotp_sendmsg+0x344/0xbf0 net/can/isotp.c:1117
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x142/0x180 net/socket.c:727
 ____sys_sendmsg+0x31e/0x4e0 net/socket.c:2566
 ___sys_sendmsg+0x17b/0x1d0 net/socket.c:2620
 __sys_sendmsg net/socket.c:2652 [inline]
 __do_sys_sendmsg net/socket.c:2657 [inline]
 __se_sys_sendmsg net/socket.c:2655 [inline]
 __x64_sys_sendmsg+0xd4/0x160 net/socket.c:2655
 x64_sys_call+0x2999/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888152db24b4 of 4 bytes by task 18884 on cpu 1:
 isotp_sendmsg+0x1d8/0xbf0 net/can/isotp.c:962
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x142/0x180 net/socket.c:727
 ____sys_sendmsg+0x345/0x4e0 net/socket.c:2566
 ___sys_sendmsg+0x17b/0x1d0 net/socket.c:2620
 __sys_sendmmsg+0x178/0x300 net/socket.c:2709
 __do_sys_sendmmsg net/socket.c:2736 [inline]
 __se_sys_sendmmsg net/socket.c:2733 [inline]
 __x64_sys_sendmmsg+0x57/0x70 net/socket.c:2733
 x64_sys_call+0x2f2f/0x2fb0 arch/x86/include/generated/asm/syscalls_64.h:308
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x00000001 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 18884 Comm: syz.8.4946 Not tainted 6.15.0-syzkaller-13743-g8630c59e9936 #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/08 08:01 upstream 8630c59e9936 4826c28e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in isotp_sendmsg / isotp_sendmsg
* Struck through repros no longer work on HEAD.