kernel BUG at fs/notify/dnotify/dnotify.c:LINE!

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 31acccdc Linux 4.19.157
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=11f01342500000
kernel config: https://syzkaller.appspot.com/x/.config?x=1f604e014c43fe09
dashboard link: https://syzkaller.appspot.com/bug?extid=088c3d7e2b0d25603e00
compiler: gcc (GCC) 10.1.0-syz 20200507
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15b7574a500000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=150d2f4a500000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+088c3d...@syzkaller.appspotmail.com

IPVS: ftp: loaded support on port[0] = 21
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kernel BUG at fs/notify/dnotify/dnotify.c:132!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 198 Comm: kworker/u4:3 Not tainted 4.19.157-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound fsnotify_mark_destroy_workfn
RIP: 0010:dnotify_free_mark fs/notify/dnotify/dnotify.c:132 [inline]
RIP: 0010:dnotify_free_mark+0x45/0x50 fs/notify/dnotify/dnotify.c:126
Code: c1 ea 03 80 3c 02 00 75 23 48 83 7d 78 00 75 15 e8 c0 fd ad ff 48 89 ee 48 8b 3d ce 08 70 09 5d e9 50 e9 e3 ff e8 ab fd ad ff <0f> 0b e8 14 25 e4 ff eb d6 66 90 41 55 49 89 fd 41 54 55 49 8d 6d
RSP: 0018:ffff8880b4e0fc58 EFLAGS: 00010293
RAX: ffff8880b4e00680 RBX: ffffffff88754900 RCX: 1ffff110169c1f99
RDX: 0000000000000000 RSI: ffffffff81b6d1b5 RDI: ffff8880abfefbb8
RBP: ffff8880abfefb40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff8880b15e3840
R13: ffff8880abfeff00 R14: ffff8880abfefb50 R15: ffff8880abfefb58
FS: 0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b8060051d8 CR3: 00000000998c6000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
fsnotify_final_mark_destroy+0x71/0xb0 fs/notify/mark.c:213
fsnotify_mark_destroy_workfn+0x1eb/0x340 fs/notify/mark.c:799
process_one_work+0x864/0x1570 kernel/workqueue.c:2155
worker_thread+0x64c/0x1130 kernel/workqueue.c:2298
kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Modules linked in:
---[ end trace db6f90bdbbff4ff1 ]---


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