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KCSAN: data-race in p9_poll_workfn / p9_write_work (6)

Status: moderation: reported on 2024/05/19 05:09
Subsystems: v9fs
[Documentation on labels]
Reported-by: syzbot+b5b4f96f34012706c09e@syzkaller.appspotmail.com
First crash: 26d, last: 9d22h
Similar bugs (5)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in p9_poll_workfn / p9_write_work (2) v9fs 1 1133d 1133d 0/27 auto-closed as invalid on 2021/06/12 15:05
upstream KCSAN: data-race in p9_poll_workfn / p9_write_work (5) v9fs 2 71d 79d 0/27 auto-obsoleted due to no activity on 2024/05/09 10:29
upstream KCSAN: data-race in p9_poll_workfn / p9_write_work (4) v9fs 1 640d 640d 0/27 auto-obsoleted due to no activity on 2022/10/18 20:14
upstream KCSAN: data-race in p9_poll_workfn / p9_write_work (3) v9fs 1 1059d 1059d 0/27 auto-closed as invalid on 2021/08/25 10:41
upstream KCSAN: data-race in p9_poll_workfn / p9_write_work v9fs 43 1651d 1695d 0/27 auto-closed as invalid on 2020/02/15 21:46

Sample crash report:
==================================================================
BUG: KCSAN: data-race in p9_poll_workfn / p9_write_work

write to 0xffff88811e999e9c of 4 bytes by task 3183 on cpu 1:
 p9_write_work+0x42c/0x750 net/9p/trans_fd.c:498
 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 0xffff88811e999e9c of 4 bytes by task 3169 on cpu 0:
 p9_poll_mux net/9p/trans_fd.c:646 [inline]
 p9_poll_workfn+0x2bf/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: 0x00000015 -> 0x00000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 3169 Comm: kworker/0:2 Not tainted 6.10.0-rc2-syzkaller-00022-g32f88d65f01b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Workqueue: events p9_poll_workfn
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/05 06:14 upstream 32f88d65f01b e1e2c66e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in p9_poll_workfn / p9_write_work
2024/05/28 19:06 upstream e0cce98fe279 34889ee3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in p9_poll_workfn / p9_write_work
2024/05/19 05:09 upstream 0450d2083be6 c0f1611a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in p9_poll_workfn / p9_write_work
* Struck through repros no longer work on HEAD.