syzbot


KCSAN: data-race in p9_conn_cancel / p9_poll_workfn (7)

Status: moderation: reported on 2024/08/31 06:59
Subsystems: v9fs
[Documentation on labels]
Reported-by: syzbot+202c94fe394d4b15e348@syzkaller.appspotmail.com
First crash: 34d, last: 19d
Similar bugs (6)
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 189d 189d 0/28 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 437d 437d 0/28 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 153d 153d 0/28 auto-obsoleted due to no activity on 2024/06/08 01:35
upstream KCSAN: data-race in p9_conn_cancel / p9_poll_workfn (6) v9fs 1 108d 108d 0/28 auto-obsoleted due to no activity on 2024/07/22 12:28
upstream KCSAN: data-race in p9_conn_cancel / p9_poll_workfn (3) v9fs 1 379d 379d 0/28 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 1133d 1133d 0/28 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 0xffff8881152eae28 of 4 bytes by task 3335 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+0x51d/0x6f0 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 0xffff8881152eae28 of 4 bytes by task 3338 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+0x51d/0x6f0 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 -> 0xffffffe0

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3338 Comm: kworker/1:4 Not tainted 6.11.0-rc7-syzkaller-00135-gb7718454f937 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Workqueue: events p9_poll_workfn
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/09/14 18:14 upstream b7718454f937 c7e35043 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in p9_conn_cancel / p9_poll_workfn
2024/08/31 06:58 upstream 20371ba12063 1eda0d14 .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.