syzbot
INFO: trying to register non-static key in gadget_dev_open
Status:
upstream: reported on 2026/08/16 22:55
Subsystems:
usb
Labels:
prio:normal
[Documentation on labels]
Reported-by: syzbot+36c086b1f7dd613facf2@syzkaller.appspotmail.com
First crash: 4d20h, last: 4d20h
Sample crash report:
INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe
you didn't initialize this object before use?
turning off the locking correctness validator.
CPU: 2 UID: 0 PID: 6814 Comm: syz.1.321 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
assign_lock_key kernel/locking/lockdep.c:984 [inline]
register_lock_class+0x549/0x560 kernel/locking/lockdep.c:1299
__lock_acquire+0x3d7/0x1a40 kernel/locking/lockdep.c:5112
lock_acquire kernel/locking/lockdep.c:5868 [inline]
lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:142 [inline]
_raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:174
spin_lock_irq include/linux/spinlock.h:372 [inline]
gadget_dev_open+0x44/0x1b0 drivers/usb/gadget/legacy/inode.c:1919
do_dentry_open+0x6ab/0x14d0 fs/open.c:947
vfs_open+0x82/0x3f0 fs/open.c:1052
do_open fs/namei.c:4700 [inline]
path_openat+0x2873/0x4280 fs/namei.c:4863
do_file_open+0x20e/0x430 fs/namei.c:4892
do_sys_openat2+0x10f/0x1e0 fs/open.c:1368
do_sys_open fs/open.c:1374 [inline]
__do_sys_openat fs/open.c:1390 [inline]
__se_sys_openat fs/open.c:1385 [inline]
__x64_sys_openat+0x12d/0x210 fs/open.c:1385
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fac6bd9e0d9
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:00007fac6cbdb028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fac6c025fa0 RCX: 00007fac6bd9e0d9
RDX: 0000000000000002 RSI: 00002000000001c0 RDI: ffffffffffffff9c
RBP: 00007fac6be35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fac6c026038 R14: 00007fac6c025fa0 R15: 00007fffa5b7a408
</TASK>
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: lib/refcount.c:25 at refcount_warn_saturate+0x111/0x130 lib/refcount.c:25, CPU#2: syz.1.321/6814
Modules linked in:
CPU: 2 UID: 0 PID: 6814 Comm: syz.1.321 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:refcount_warn_saturate+0x111/0x130 lib/refcount.c:25
Code: 06 e8 f3 92 ec fc 48 8d 3d fc bd 0e 0c 67 48 0f b9 3a e8 e2 92 ec fc 5b 5d c3 cc cc cc cc e8 d6 92 ec fc 48 8d 3d ef bd 0e 0c <67> 48 0f b9 3a e8 c5 92 ec fc 5b 5d c3 cc cc cc cc 48 89 df e8 36
RSP: 0018:ffffc9000c607980 EFLAGS: 00010087
RAX: 0000000000013641 RBX: ffff888057f44040 RCX: ffffc90007002000
RDX: 0000000000080000 RSI: ffffffff851de0aa RDI: ffffffff912c9ea0
RBP: 0000000000000002 R08: 0000000000000005 R09: 0000000000000004
R10: 0000000000000002 R11: ffff888057f44018 R12: ffff888057f44040
R13: ffff88803986aac0 R14: ffff88803986ab08 R15: ffff88803986aae8
FS: 00007fac6cbdb6c0(0000) GS:ffff8880d5fec000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3ae428 CR3: 000000002b4e3000 CR4: 0000000000352ef0
Call Trace:
<TASK>
__refcount_add include/linux/refcount.h:289 [inline]
__refcount_inc include/linux/refcount.h:366 [inline]
refcount_inc include/linux/refcount.h:383 [inline]
get_dev drivers/usb/gadget/legacy/inode.c:160 [inline]
gadget_dev_open+0x170/0x1b0 drivers/usb/gadget/legacy/inode.c:1924
do_dentry_open+0x6ab/0x14d0 fs/open.c:947
vfs_open+0x82/0x3f0 fs/open.c:1052
do_open fs/namei.c:4700 [inline]
path_openat+0x2873/0x4280 fs/namei.c:4863
do_file_open+0x20e/0x430 fs/namei.c:4892
do_sys_openat2+0x10f/0x1e0 fs/open.c:1368
do_sys_open fs/open.c:1374 [inline]
__do_sys_openat fs/open.c:1390 [inline]
__se_sys_openat fs/open.c:1385 [inline]
__x64_sys_openat+0x12d/0x210 fs/open.c:1385
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fac6bd9e0d9
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:00007fac6cbdb028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fac6c025fa0 RCX: 00007fac6bd9e0d9
RDX: 0000000000000002 RSI: 00002000000001c0 RDI: ffffffffffffff9c
RBP: 00007fac6be35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fac6c026038 R14: 00007fac6c025fa0 R15: 00007fffa5b7a408
</TASK>
----------------
Code disassembly (best guess), 1 bytes skipped:
0: e8 f3 92 ec fc call 0xfcec92f8
5: 48 8d 3d fc bd 0e 0c lea 0xc0ebdfc(%rip),%rdi # 0xc0ebe08
c: 67 48 0f b9 3a ud1 (%edx),%rdi
11: e8 e2 92 ec fc call 0xfcec92f8
16: 5b pop %rbx
17: 5d pop %rbp
18: c3 ret
19: cc int3
1a: cc int3
1b: cc int3
1c: cc int3
1d: e8 d6 92 ec fc call 0xfcec92f8
22: 48 8d 3d ef bd 0e 0c lea 0xc0ebdef(%rip),%rdi # 0xc0ebe18
* 29: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2e: e8 c5 92 ec fc call 0xfcec92f8
33: 5b pop %rbx
34: 5d pop %rbp
35: c3 ret
36: cc int3
37: cc int3
38: cc int3
39: cc int3
3a: 48 89 df mov %rbx,%rdi
3d: e8 .byte 0xe8
3e: 36 ss
Struck through repros no longer work on HEAD.