syzbot


KCSAN: data-race in p9_conn_cancel / p9_poll_workfn (6)

Status: moderation: reported on 2024/06/17 12:28
Subsystems: v9fs
[Documentation on labels]
Reported-by: syzbot+b4d211ced36373fe2b84@syzkaller.appspotmail.com
First crash: 31d, last: 31d
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in p9_conn_cancel / p9_poll_workfn (4) v9fs 1 112d 112d 0/27 auto-obsoleted due to no activity on 2024/05/02 19:52
upstream KCSAN: data-race in p9_conn_cancel / p9_poll_workfn (2) v9fs 1 360d 360d 0/27 auto-obsoleted due to no activity on 2023/08/28 09:43
upstream KCSAN: data-race in p9_conn_cancel / p9_poll_workfn (5) v9fs 1 76d 76d 0/27 auto-obsoleted due to no activity on 2024/06/08 01:35
upstream KCSAN: data-race in p9_conn_cancel / p9_poll_workfn (3) v9fs 1 302d 302d 0/27 auto-obsoleted due to no activity on 2023/10/26 00:39
upstream KCSAN: data-race in p9_conn_cancel / p9_poll_workfn v9fs 1 1056d 1056d 0/27 auto-closed as invalid on 2021/10/01 19:17

Sample crash report:
==================================================================
BUG: KCSAN: data-race in p9_conn_cancel / p9_poll_workfn

write to 0xffff888116978028 of 4 bytes by task 3178 on cpu 0:
 p9_conn_cancel+0x89/0x400 net/9p/trans_fd.c:199
 p9_write_work+0x3ac/0x750 net/9p/trans_fd.c:522
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3312
 worker_thread+0x526/0x730 kernel/workqueue.c:3393
 kthread+0x1d1/0x210 kernel/kthread.c:389
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

read to 0xffff888116978028 of 4 bytes by task 7207 on cpu 1:
 p9_poll_mux net/9p/trans_fd.c:625 [inline]
 p9_poll_workfn+0xc0/0x420 net/9p/trans_fd.c:1177
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3312
 worker_thread+0x526/0x730 kernel/workqueue.c:3393
 kthread+0x1d1/0x210 kernel/kthread.c:389
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

value changed: 0x00000000 -> 0xffffff8f

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7207 Comm: kworker/1:12 Tainted: G        W          6.10.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Workqueue: events p9_poll_workfn
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/17 12:27 upstream 6ba59ff42279 1f11cfd7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in p9_conn_cancel / p9_poll_workfn
* Struck through repros no longer work on HEAD.