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

[syzbot <syzbot+e29d28728f38190cecfc@syzkaller.appspotmail.com>]

Hello,

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

IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
------------[ cut here ]------------
ODEBUG: free active (active state 1) object: ffff88802a236ca8 object type: rcu_head hint: 0x0
WARNING: CPU: 0 PID: 899 at lib/debugobjects.c:509 debug_print_object+0x194/0x2c0 lib/debugobjects.c:509
Modules linked in:
CPU: 0 PID: 899 Comm: kworker/0:2 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
Workqueue: events io_fallback_req_func
RIP: 0010:debug_print_object+0x194/0x2c0 lib/debugobjects.c:509
Code: df 48 89 fe 48 c1 ee 03 80 3c 16 00 0f 85 c7 00 00 00 48 8b 14 dd c0 dc a6 8a 50 4c 89 ee 48 c7 c7 80 d0 a6 8a e8 40 76 ae 05 <0f> 0b 58 83 05 0e 25 66 0a 01 48 83 c4 20 5b 5d 41 5c 41 5d 41 5e
RSP: 0018:ffffc90004aef950 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000
RDX: ffff88801eba3a80 RSI: ffffffff8166972c RDI: fffff5200095df1c
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8a4dd0a0
R13: ffffffff8aa6d580 R14: ffff888070a92da8 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005639964dc950 CR3: 000000007dcca000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __debug_check_no_obj_freed lib/debugobjects.c:996 [inline]
 debug_check_no_obj_freed+0x305/0x420 lib/debugobjects.c:1027
 slab_free_hook mm/slub.c:1756 [inline]
 slab_free_freelist_hook+0xeb/0x1c0 mm/slub.c:1807
 slab_free mm/slub.c:3787 [inline]
 kmem_cache_free+0xec/0x4e0 mm/slub.c:3809
 put_task_struct_many include/linux/sched/task.h:125 [inline]
 __io_put_task+0x155/0x1e0 io_uring/io_uring.c:729
 io_put_task io_uring/io_uring.h:328 [inline]
 __io_req_complete_post+0x7ec/0xd20 io_uring/io_uring.c:982
 io_req_complete_post+0xf1/0x1a0 io_uring/io_uring.c:998
 io_req_task_complete+0x189/0x260 io_uring/io_uring.c:1636
 io_poll_task_func+0xa95/0x1220 io_uring/poll.c:347
 io_fallback_req_func+0xfd/0x204 io_uring/io_uring.c:252
 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=17a99c7a480000
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=1145447e480000