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KCSAN: data-race in p9_conn_cancel / p9_write_work (5)

Status: moderation: reported on 2024/04/07 07:31
Subsystems: v9fs
[Documentation on labels]
Reported-by: syzbot+ea89179830fc4c224e62@syzkaller.appspotmail.com
First crash: 51d, last: 10d
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in p9_conn_cancel / p9_write_work (4) v9fs 2 182d 205d 0/26 auto-obsoleted due to no activity on 2024/01/02 07:46
upstream KCSAN: data-race in p9_conn_cancel / p9_write_work v9fs 1 1280d 1263d 0/26 auto-closed as invalid on 2020/12/30 07:04
upstream KCSAN: data-race in p9_conn_cancel / p9_write_work (3) v9fs 1 769d 769d 0/26 auto-closed as invalid on 2022/05/24 19:24
upstream KCSAN: data-race in p9_conn_cancel / p9_write_work (2) v9fs 2 1211d 1223d 0/26 auto-closed as invalid on 2021/03/08 14:39

Sample crash report:
==================================================================
BUG: KCSAN: data-race in p9_conn_cancel / p9_write_work

write to 0xffff8881443bd828 of 4 bytes by task 19633 on cpu 0:
 p9_conn_cancel+0x89/0x400 net/9p/trans_fd.c:199
 p9_poll_mux net/9p/trans_fd.c:631 [inline]
 p9_poll_workfn+0x133/0x420 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

read to 0xffff8881443bd828 of 4 bytes by task 19705 on cpu 1:
 p9_write_work+0x26/0x750 net/9p/trans_fd.c:453
 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 -> 0xffffff98

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 19705 Comm: kworker/1:18 Tainted: G        W          6.9.0-syzkaller-08284-gea5f6ad9ad96 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Workqueue: events p9_write_work
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/17 12:43 upstream ea5f6ad9ad96 a12e99e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in p9_conn_cancel / p9_write_work
2024/05/02 06:50 upstream 0106679839f7 3ba885bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in p9_conn_cancel / p9_write_work
2024/04/07 07:30 upstream f2f80ac80987 ca620dd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in p9_conn_cancel / p9_write_work
* Struck through repros no longer work on HEAD.