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

From: syzbot <syzbot+e3ec01fd2d18c9264c3b@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_rawmidi_poll
Date: Fri, 13 Jan 2023 02:48:19 -0800	[thread overview]
Message-ID: <000000000000bb710c05f222f8e6@google.com> (raw)
In-Reply-To: <20230113102834.768-1-hdanton@sina.com>

Hello,

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

------------[ cut here ]------------
WARNING: CPU: 0 PID: 5602 at kernel/sched/wait.c:248 __wake_up_pollfree+0x44/0x60 kernel/sched/wait.c:249
Modules linked in:
CPU: 0 PID: 5602 Comm: syz-executor.0 Not tainted 6.2.0-rc3-next-20230112-syzkaller-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:__wake_up_pollfree+0x44/0x60 kernel/sched/wait.c:248
Code: 29 ff ff 48 8d 6b 40 48 b8 00 00 00 00 00 fc ff df 48 89 ea 48 c1 ea 03 80 3c 02 00 75 11 48 8b 43 40 48 39 c5 75 03 5b 5d c3 <0f> 0b 5b 5d c3 48 89 ef e8 ef d1 6d 00 eb e5 66 66 2e 0f 1f 84 00
RSP: 0018:ffffc90004fafab0 EFLAGS: 00010297
RAX: ffffc90004fbfcd8 RBX: ffff888075f56a50 RCX: 0000000000000000
RDX: 1ffff1100ebead52 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffff888075f56a90 R08: 0000000000000001 R09: ffffffff91353c67
R10: 0000000000000001 R11: 000000000009d400 R12: ffff888075f56a90
R13: 0000000000000001 R14: ffff88814a092100 R15: ffff88801c690050
FS:  00007f49e15dd700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005598bec2d000 CR3: 000000002b119000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 wake_up_pollfree include/linux/wait.h:271 [inline]
 snd_rawmidi_runtime_free sound/core/rawmidi.c:191 [inline]
 close_substream.part.0+0x229/0x8a0 sound/core/rawmidi.c:571
 close_substream sound/core/rawmidi.c:545 [inline]
 rawmidi_release_priv+0x192/0x270 sound/core/rawmidi.c:588
 snd_rawmidi_release+0x87/0x120 sound/core/rawmidi.c:625
 __fput+0x27c/0xa90 fs/file_table.c:321
 task_work_run+0x16f/0x270 kernel/task_work.c:179
 get_signal+0x1c7/0x24f0 kernel/signal.c:2635
 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306
 exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297
 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f49e228c0c9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f49e15dd218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f49e23ac058 RCX: 00007f49e228c0c9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f49e23ac058
RBP: 00007f49e23ac050 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f49e23ac05c
R13: 00007ffe4d1f3a2f R14: 00007f49e15dd300 R15: 0000000000022000
 </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=1498500e480000
kernel config:  https://syzkaller.appspot.com/x/.config?x=835f3591019836d5
dashboard link: https://syzkaller.appspot.com/bug?extid=e3ec01fd2d18c9264c3b
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=12a8ed16480000