syzbot


KCSAN: data-race in bcm_can_tx / bcm_tx_setup

Status: moderation: reported on 2022/06/11 01:13
Reported-by: syzbot+2f413a9780513109f6c9@syzkaller.appspotmail.com
First crash: 23d, last: 8d21h

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

read to 0xffff888137974d00 of 4 bytes by interrupt on cpu 0:
 bcm_can_tx+0x4e/0x3e0 net/can/bcm.c:275
 bcm_tx_timeout_handler+0xce/0x250
 __run_hrtimer+0x132/0x420 kernel/time/hrtimer.c:1685
 __hrtimer_run_queues kernel/time/hrtimer.c:1749 [inline]
 hrtimer_run_softirq+0x1e9/0x480 kernel/time/hrtimer.c:1766
 __do_softirq+0x158/0x2e3 kernel/softirq.c:571
 run_ksoftirqd+0x1f/0x30 kernel/softirq.c:934
 smpboot_thread_fn+0x308/0x4a0 kernel/smpboot.c:164
 kthread+0x1a9/0x1e0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30

write to 0xffff888137974d00 of 4 bytes by task 16172 on cpu 1:
 bcm_tx_setup+0x73f/0xde0 net/can/bcm.c:981
 bcm_sendmsg+0x17f/0x400 net/can/bcm.c:1335
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg net/socket.c:734 [inline]
 ____sys_sendmsg+0x38f/0x500 net/socket.c:2492
 ___sys_sendmsg net/socket.c:2546 [inline]
 __sys_sendmsg+0x197/0x230 net/socket.c:2575
 __do_sys_sendmsg net/socket.c:2584 [inline]
 __se_sys_sendmsg net/socket.c:2582 [inline]
 __x64_sys_sendmsg+0x42/0x50 net/socket.c:2582
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

value changed: 0x0000000e -> 0x00000010

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 16172 Comm: syz-executor.2 Not tainted 5.19.0-rc2-syzkaller-00060-g30306f6194ca-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/06/16 13:20 upstream 30306f6194ca 1719ee24 .config log report info KCSAN: data-race in bcm_can_tx / bcm_tx_setup
ci2-upstream-kcsan-gce 2022/06/01 20:13 upstream 8eca6b0a647a b4bc6a3d .config log report info KCSAN: data-race in bcm_can_tx / bcm_tx_setup