Re: [syzbot] [kernel] WARNING: locking bug in try_to_wake_up

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
VFS: Busy inodes after unmount (use-after-free)

VFS: Busy inodes after unmount of loop0 (btrfs)
------------[ cut here ]------------
kernel BUG at fs/super.c:652!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 0 UID: 0 PID: 5883 Comm: syz-executor Not tainted 6.12.0-rc1-syzkaller-00031-ge32cde8d2bd7-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:generic_shutdown_super+0x2ca/0x2d0 fs/super.c:650
Code: 1b 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 39 28 ed ff 48 8b 13 48 c7 c7 40 bd 18 8c 4c 89 e6 e8 f7 65 ab 09 90 <0f> 0b 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90004217d10 EFLAGS: 00010246
RAX: 000000000000002f RBX: ffffffff8ee96c40 RCX: 5f1cd68d4a54fd00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 1ffff1100dde90f0 R08: ffffffff81749d9c R09: 1ffff92000842f3c
R10: dffffc0000000000 R11: fffff52000842f3d R12: ffff88806ef48668
R13: dffffc0000000000 R14: ffffffff8c4bc158 R15: ffff88806ef48780
FS:  0000555593b76500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f019f6ff866 CR3: 000000003235e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 kill_anon_super+0x3b/0x70 fs/super.c:1237
 btrfs_kill_super+0x41/0x50 fs/btrfs/super.c:2121
 deactivate_locked_super+0xc4/0x130 fs/super.c:473
 cleanup_mnt+0x41f/0x4b0 fs/namespace.c:1373
 task_work_run+0x24f/0x310 kernel/task_work.c:228
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9ce297f327
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffedd46b3d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f9ce297f327
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffedd46b490
RBP: 00007ffedd46b490 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffedd46c510
R13: 00007f9ce29f0134 R14: 000000000001a3f1 R15: 00007ffedd46c550
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:generic_shutdown_super+0x2ca/0x2d0 fs/super.c:650
Code: 1b 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 39 28 ed ff 48 8b 13 48 c7 c7 40 bd 18 8c 4c 89 e6 e8 f7 65 ab 09 90 <0f> 0b 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90004217d10 EFLAGS: 00010246
RAX: 000000000000002f RBX: ffffffff8ee96c40 RCX: 5f1cd68d4a54fd00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 1ffff1100dde90f0 R08: ffffffff81749d9c R09: 1ffff92000842f3c
R10: dffffc0000000000 R11: fffff52000842f3d R12: ffff88806ef48668
R13: dffffc0000000000 R14: ffffffff8c4bc158 R15: ffff88806ef48780
FS:  0000555593b76500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f019f6ff866 CR3: 000000003235e000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


Tested on:

commit:         e32cde8d Merge tag 'sched_ext-for-6.12-rc1-fixes-1' of..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13b03dd0580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=1f009dd80b3799c2
dashboard link: https://syzkaller.appspot.com/bug?extid=8aaf2df2ef0164ffe1fb
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=10a3c777980000