[v5.15] WARNING: locking bug in dev_open

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 28c35638ec51 Linux 5.15.219
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17e73d79580000
kernel config: https://syzkaller.appspot.com/x/.config?x=21845b39f8fc6be8
dashboard link: https://syzkaller.appspot.com/bug?extid=08fb944ed90576ba6193
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/baa03a1911e6/disk-28c35638.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/fc932057f792/vmlinux-28c35638.xz
kernel image: https://storage.googleapis.com/syzbot-assets/2d0d901fc7bd/bzImage-28c35638.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+08fb94...@syzkaller.appspotmail.com

------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(!test_bit(class_idx, lock_classes_in_use))
WARNING: CPU: 1 PID: 6553 at kernel/locking/lockdep.c:4982 __lock_acquire+0x5a9d/0x7b50 kernel/locking/lockdep.c:4982
Modules linked in:
CPU: 1 PID: 6553 Comm: syz.3.591 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__lock_acquire+0x5a9d/0x7b50 kernel/locking/lockdep.c:4982
Code: 04 08 84 c0 0f 85 4e 1c 00 00 83 3d 24 f8 2d 0c 00 0f 85 bd b7 ff ff 48 c7 c7 80 2a 2b 8a 48 c7 c6 20 53 2b 8a e8 53 1f 58 08 <0f> 0b e9 a3 b7 ff ff 0f 0b e9 dd b8 ff ff 89 c1 84 c9 0f 85 aa b3
RSP: 0018:ffffc9000358f4a0 EFLAGS: 00010046
RAX: 76232b6753746d00 RBX: 0000000001eb0b3e RCX: 0000000000080000
RDX: ffffc90005761000 RSI: 00000000000032fa RDI: 00000000000032fb
RBP: ffffc9000358f6d0 R08: ffff8880b912795b R09: 1ffff11017224f2b
R10: dffffc0000000000 R11: ffffed1017224f2c R12: ffff888022e20b10
R13: ffff888022e20000 R14: 0000000000000000 R15: ffff888022e20af0
FS: 00007f446d1bb6c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32921ff8 CR3: 000000001fa31000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
_raw_spin_lock_irq+0xab/0xf0 kernel/locking/spinlock.c:170
spin_lock_irq include/linux/spinlock.h:389 [inline]
dev_open+0x47/0x1b0 drivers/usb/gadget/legacy/inode.c:1917
do_dentry_open+0x7f7/0xf90 fs/open.c:826
do_open fs/namei.c:3659 [inline]
path_openat+0x2718/0x2fb0 fs/namei.c:3793
do_filp_open+0x1df/0x400 fs/namei.c:3820
do_sys_openat2+0x14b/0x500 fs/open.c:1255
do_sys_open fs/open.c:1271 [inline]
__do_sys_openat fs/open.c:1287 [inline]
__se_sys_openat fs/open.c:1282 [inline]
__x64_sys_openat+0x135/0x160 fs/open.c:1282
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f446ef63159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f446d1bb028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f446f1eafa0 RCX: 00007f446ef63159
RDX: 0000000000000802 RSI: 0000200000000300 RDI: ffffffffffffff9c
RBP: 00007f446effa024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f446f1eb038 R14: 00007f446f1eafa0 R15: 00007ffe1647ce28
</TASK>


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