Re: [syzbot] kernel BUG in dnotify_free_mark

[syzbot]

Hello,

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

------------[ cut here ]------------
WARNING: CPU: 0 PID: 4068 at fs/notify/mark.c:336 fsnotify_put_mark+0x8b6/0x9c0
Modules linked in:
CPU: 0 PID: 4068 Comm: syz-executor.0 Not tainted 6.1.0-rc2-syzkaller-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
RIP: 0010:fsnotify_put_mark+0x8b6/0x9c0 fs/notify/mark.c:336
Code: 0c b9 01 00 00 00 bf 08 00 00 00 48 c7 c2 e0 9b c4 8c 48 83 c4 40 5b 41 5c 41 5d 41 5e 41 5f 5d e9 2f c7 58 ff e8 fa 34 8a ff <0f> 0b e9 02 ff ff ff e8 ee 34 8a ff 0f 0b e9 24 f9 ff ff e8 e2 34
RSP: 0018:ffffc90004d1fb48 EFLAGS: 00010293
RAX: ffffffff81fd9a26 RBX: 0000000000000001 RCX: ffff888020cd9d40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff88806eda6000 R08: ffffffff81fd991b R09: fffffbfff1c1b5e6
R10: fffffbfff1c1b5e6 R11: 1ffffffff1c1b5e5 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff88807efa7900 R15: 1ffff1100ddb4c0e
FS:  0000555556a00400(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056399dba2950 CR3: 000000006d41b000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 fsnotify_destroy_marks+0x57d/0x6f0 fs/notify/mark.c:868
 fsnotify_clear_marks_by_inode fs/notify/fsnotify.h:60 [inline]
 __fsnotify_inode_delete fs/notify/fsnotify.c:22 [inline]
 fsnotify_inode_delete include/linux/fsnotify.h:176 [inline]
 fsnotify_unmount_inodes fs/notify/fsnotify.c:78 [inline]
 fsnotify_sb_delete+0x287/0x4e0 fs/notify/fsnotify.c:92
 generic_shutdown_super+0x9c/0x310 fs/super.c:481
 kill_block_super+0x79/0xd0 fs/super.c:1427
 deactivate_locked_super+0xa7/0xf0 fs/super.c:331
 cleanup_mnt+0x494/0x520 fs/namespace.c:1186
 task_work_run+0x243/0x300 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0x124/0x150 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0xb2/0x140 kernel/entry/common.c:203
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:296
 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f7892a8ca67
Code: ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 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 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe3a5680c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f7892a8ca67
RDX: 00007ffe3a568199 RSI: 000000000000000a RDI: 00007ffe3a568190
RBP: 00007ffe3a568190 R08: 00000000ffffffff R09: 00007ffe3a567f60
R10: 0000555556a018b3 R11: 0000000000000246 R12: 00007f7892ae5826
R13: 00007ffe3a569250 R14: 0000555556a01810 R15: 00007ffe3a569290
 </TASK>


Tested on:

commit:         247f34f7 Linux 6.1-rc2
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=1479cab6880000
kernel config:  https://syzkaller.appspot.com/x/.config?x=1d3548a4365ba17d
dashboard link: https://syzkaller.appspot.com/bug?extid=06cc05ddc896f12b7ec5
compiler:       Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
patch:          https://syzkaller.appspot.com/x/patch.diff?x=11cb6f5e880000