WARNING: still has locks held in io_ring_submit

WARNING: still has locks held in io_ring_submit_lock

Status: fixed on 2023/02/24 13:50
Subsystems: fs io-uring
[Documentation on labels]
Reported-by: syzbot+987d7bb19195ae45208c@syzkaller.appspotmail.com
Fix commit: e7637a492b9f io_uring: fix locking state for empty buffer group
First crash: 850d, last: 849d

Cause bisection: introduced by (bisect log) :
commit 6da69b1da130e7d96766042750cd9f902e890eba
Author: Xiaomeng Tong <xiam0nd.tong@gmail.com>
Date: Mon Mar 28 03:24:31 2022 +0000

net: dsa: bcm_sf2_cfp: fix an incorrect NULL check on list iterator

Crash: SYZFATAL: executor failed NUM times: executor NUM: failed to write control pipe: write |NUM: broken pipe (log)
Repro: C syz .config

▶ ▼ Discussions (2)

Title	Replies (including bot)	Last reply
[syzbot] WARNING: still has locks held in io_ring_submit_lock	2 (5)	2022/05/15 18:06
[PATCH] io_uring: fix locking state for empty buffer group	1 (1)	2022/05/15 17:24

▶ ▼ Last patch testing requests (2)


Created	Duration	User	Patch	Repo	Result
2022/05/15 17:45	17m	axboe@kernel.dk		git://git.kernel.dk/linux-block.git for-next	OK
2022/05/15 17:23	9m	axboe@kernel.dk		git://git.kernel.dk/linux-block.git for-next	report log

Sample crash report:

====================================
WARNING: iou-wrk-3613/3623 still has locks held!
5.18.0-rc6-next-20220513-syzkaller #0 Not tainted
------------------------------------
1 lock held by iou-wrk-3613/3623:
 #0: ffff888140bfe0a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_ring_submit_lock+0x75/0xc0 fs/io_uring.c:1494

stack backtrace:
CPU: 0 PID: 3623 Comm: iou-wrk-3613 Not tainted 5.18.0-rc6-next-20220513-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 try_to_freeze include/linux/freezer.h:66 [inline]
 get_signal+0x1424/0x2600 kernel/signal.c:2647
 io_wqe_worker+0x64b/0xdb0 fs/io-wq.c:663
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:297
 </TASK>

Crashes (3):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Manager	Title
2022/05/15 01:09	linux-next	1e1b28b936ae	744a39e2	.config	strace log	report	syz	C		ci-upstream-linux-next-kasan-gce-root	WARNING: still has locks held in io_ring_submit_lock
2022/05/15 19:31	linux-next	1e1b28b936ae	744a39e2	.config	console log	report			info	ci-upstream-linux-next-kasan-gce-root	WARNING: still has locks held in io_ring_submit_lock
2022/05/15 00:53	linux-next	1e1b28b936ae	744a39e2	.config	console log	report			info	ci-upstream-linux-next-kasan-gce-root	WARNING: still has locks held in io_ring_submit_lock

* ~~Struck through~~ repros no longer work on HEAD.