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KCSAN: data-race in p9_conn_cancel / p9_read_work (2)

Status: moderation: reported on 2024/06/08 05:58
Subsystems: v9fs
[Documentation on labels]
Reported-by: syzbot+a93db7f68817fbc637f8@syzkaller.appspotmail.com
First crash: 14d, last: 14d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in p9_conn_cancel / p9_read_work v9fs 1 97d 97d 0/27 auto-obsoleted due to no activity on 2024/04/21 04:20

Sample crash report:
==================================================================
BUG: KCSAN: data-race in p9_conn_cancel / p9_read_work

write to 0xffff888148981428 of 4 bytes by task 4813 on cpu 1:
 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 0xffff888148981428 of 4 bytes by task 4823 on cpu 0:
 p9_read_work+0x34/0x8d0 net/9p/trans_fd.c:286
 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 -> 0xffffffe0

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 4823 Comm: kworker/0:8 Not tainted 6.10.0-rc2-syzkaller-00269-g96e09b8f8166 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Workqueue: events p9_read_work
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/08 05:57 upstream 96e09b8f8166 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in p9_conn_cancel / p9_read_work
* Struck through repros no longer work on HEAD.