[moderation] [fs?] WARNING in notify_change (9)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: cc3aa43b44bd Add linux-next specific files for 20251219
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=15908f92580000
kernel config: https://syzkaller.appspot.com/x/.config?x=da1bc82c6189c463
dashboard link: https://syzkaller.appspot.com/bug?extid=351b1ebed93668c52f52
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
CC: [bra...@kernel.org ja...@suse.cz linux-...@vger.kernel.org linux-...@vger.kernel.org vi...@zeniv.linux.org.uk]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/30bf539e6f28/disk-cc3aa43b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0e2f8b08e342/vmlinux-cc3aa43b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ec7ee6ece11f/bzImage-cc3aa43b.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+351b1e...@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: fs/attr.c:426 at notify_change+0xc80/0xf40 fs/attr.c:426, CPU#1: syz.4.544/8501
Modules linked in:
CPU: 1 UID: 0 PID: 8501 Comm: syz.4.544 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:notify_change+0xc80/0xf40 fs/attr.c:426
Code: 89 ff 4c 89 ee 89 ea e8 fe 3b fe 01 31 db 89 d8 48 83 c4 50 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 71 35 7f ff 90 <0f> 0b 90 e9 57 f4 ff ff 89 d9 80 e1 07 fe c1 38 c1 0f 8c da f3 ff
RSP: 0018:ffffc9000479fbd8 EFLAGS: 00010287
RAX: ffffffff824282ef RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000e7fa000 RSI: 0000000000001343 RDI: 0000000000001344
RBP: 0000000000000046 R08: ffff8880584c80df R09: 1ffff1100b09901b
R10: dffffc0000000000 R11: ffffed100b09901c R12: ffff8880584c80d8
R13: ffffc9000479fd00 R14: ffff888056874468 R15: dffffc0000000000
FS: 00007fde99d6b6c0(0000) GS:ffff888125d25000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f16903fc260 CR3: 000000007dc1c000 CR4: 00000000003526f0
Call Trace:
<TASK>
chown_common+0x441/0x670 fs/open.c:788
do_fchownat+0x161/0x270 fs/open.c:819
__do_sys_fchownat fs/open.c:834 [inline]
__se_sys_fchownat fs/open.c:831 [inline]
__x64_sys_fchownat+0xb5/0xd0 fs/open.c:831
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fde98f8f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fde99d6b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000104
RAX: ffffffffffffffda RBX: 00007fde991e6090 RCX: 00007fde98f8f749
RDX: 0000000000000000 RSI: 0000200000000100 RDI: ffffffffffffff9c
RBP: 00007fde99013f91 R08: 0000000000001000 R09: 0000000000000000
R10: 000000000000ee01 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fde991e6128 R14: 00007fde991e6090 R15: 00007fffbe97f428
</TASK>


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