Re: [syzbot] KASAN: use-after-free Read in snd_pcm_post_stop

From: syzbot <syzbot+e29d28728f38190cecfc@syzkaller.appspotmail.com>
To: hdanton@sina.com, linux-kernel@vger.kernel.org,
	syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] KASAN: use-after-free Read in snd_pcm_post_stop
Date: Wed, 18 Jan 2023 06:07:20 -0800	[thread overview]
Message-ID: <000000000000b1150f05f28a55fd@google.com> (raw)
In-Reply-To: <20230118094915.2906-1-hdanton@sina.com>

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in io_ring_exit_work

------------[ cut here ]------------
WARNING: CPU: 0 PID: 11 at io_uring/io_uring.c:2977 io_ring_exit_work+0x320/0xc80 io_uring/io_uring.c:2977
Modules linked in:
CPU: 0 PID: 11 Comm: kworker/u4:1 Not tainted 6.2.0-rc3-next-20230112-syzkaller-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
Workqueue: events_unbound io_ring_exit_work
RIP: 0010:io_ring_exit_work+0x320/0xc80 io_uring/io_uring.c:2977
Code: 40 8c e8 57 f4 02 f8 48 8b 05 f0 59 74 02 31 ff 4c 8b 74 24 10 49 29 c6 4c 89 f6 e8 8e 21 b5 f7 4d 85 f6 79 10 e8 b4 24 b5 f7 <0f> 0b 48 c7 44 24 08 70 17 00 00 e8 a4 24 b5 f7 48 8b 74 24 08 48
RSP: 0018:ffffc90000107bd0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff88807969a838 RCX: 0000000000000000
RDX: ffff88813fe4ba80 RSI: ffffffff89cc982c RDI: 0000000000000007
RBP: ffff88807969a000 R08: 0000000000000007 R09: 0000000000000000
R10: fffffffffffffffe R11: 0000000000000000 R12: dffffc0000000000
R13: ffff88807969a040 R14: fffffffffffffffe R15: ffff88807969a3c8
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555568ee708 CR3: 0000000029c9e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 process_one_work+0x9bf/0x1750 kernel/workqueue.c:2293
 worker_thread+0x669/0x1090 kernel/workqueue.c:2440
 kthread+0x2e8/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>

Tested on:

commit:         0a093b28 Add linux-next specific files for 20230112
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
console output: https://syzkaller.appspot.com/x/log.txt?x=118c8241480000
kernel config:  https://syzkaller.appspot.com/x/.config?x=835f3591019836d5
dashboard link: https://syzkaller.appspot.com/bug?extid=e29d28728f38190cecfc
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
patch:          https://syzkaller.appspot.com/x/patch.diff?x=15607d19480000