syzbot


WARNING: refcount bug in p9_tag_lookup

Status: moderation: reported on 2022/04/12 15:13
Reported-by: syzbot+0a99744ed856bf4580fa@syzkaller.appspotmail.com
First crash: 178d, last: 69d

Sample crash report:
------------[ cut here ]------------
refcount_t: saturated; leaking memory.
WARNING: CPU: 0 PID: 3701 at lib/refcount.c:19 refcount_warn_saturate+0xf4/0x1e0 lib/refcount.c:19
Modules linked in:
CPU: 0 PID: 3701 Comm: kworker/0:7 Not tainted 5.19.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
Workqueue: events p9_read_work
RIP: 0010:refcount_warn_saturate+0xf4/0x1e0 lib/refcount.c:19
Code: 1d 7d f9 a9 09 31 ff 89 de e8 18 4e 7d fd 84 db 75 ab e8 0f 52 7d fd 48 c7 c7 a0 03 28 8a c6 05 5d f9 a9 09 01 e8 28 fe 35 05 <0f> 0b eb 8f e8 f3 51 7d fd 0f b6 1d 47 f9 a9 09 31 ff 89 de e8 e3
RSP: 0018:ffffc9000353fb78 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888046a7a140 RSI: ffffffff815ffd38 RDI: fffff520006a7f61
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000001 R12: ffff88823bd94f48
R13: dffffc0000000000 R14: 0000000000000000 R15: 00000000a9a8abaa
FS:  0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555555cc3848 CR3: 000000004a8ec000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __refcount_add_not_zero include/linux/refcount.h:163 [inline]
 __refcount_inc_not_zero include/linux/refcount.h:227 [inline]
 refcount_inc_not_zero include/linux/refcount.h:245 [inline]
 kref_get_unless_zero include/linux/kref.h:111 [inline]
 p9_req_try_get include/net/9p/client.h:235 [inline]
 p9_tag_lookup+0x2b3/0x570 net/9p/client.c:341
 p9_read_work+0x759/0x1020 net/9p/trans_fd.c:334
 process_one_work+0x996/0x1610 kernel/workqueue.c:2289
 worker_thread+0x665/0x1080 kernel/workqueue.c:2436
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-selinux-root 2022/07/26 03:24 upstream e0dccc3b76fb 34795c51 .config log report info WARNING: refcount bug in p9_tag_lookup
ci-upstream-kasan-gce-root 2022/05/05 06:08 upstream a7391ad35724 dc9e5259 .config log report info WARNING: refcount bug in p9_tag_lookup
ci-upstream-linux-next-kasan-gce-root 2022/04/08 15:11 linux-next ff511c1c68a5 15be3cba .config log report info WARNING: refcount bug in p9_tag_lookup
* Struck through repros no longer work on HEAD.