syzbot
WARNING in usbg_make_tpg
Status:
upstream: reported on 2026/07/31 00:12
Subsystems:
usb
Labels:
prio:low
[Documentation on labels]
Reported-by: syzbot+2f343b3fdaa0a1c5d9c8@syzkaller.appspotmail.com
First crash: 21d, last: 5d23h
Sample crash report:
------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: kernel/locking/mutex.c:625 at __mutex_lock_common kernel/locking/mutex.c:625 [inline], CPU#0: syz.0.0/5316
WARNING: kernel/locking/mutex.c:625 at __mutex_lock+0x12d8/0x1550 kernel/locking/mutex.c:821, CPU#0: syz.0.0/5316
Modules linked in:
CPU: 0 UID: 0 PID: 5316 Comm: syz.0.0 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:__mutex_lock_common kernel/locking/mutex.c:625 [inline]
RIP: 0010:__mutex_lock+0x12df/0x1550 kernel/locking/mutex.c:821
Code: a0 57 90 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 47 02 00 00 83 3d 45 4e 83 04 00 75 13 48 8d 3d c8 9d 86 04 48 c7 c6 40 f7 ec 8b <67> 48 0f b9 3a 90 e9 75 ee ff ff 90 0f 0b 90 e9 48 f2 ff ff 90 0f
RSP: 0018:ffffc9000f207980 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000100000
RDX: ffffc9000e9ca000 RSI: ffffffff8becf740 RDI: ffffffff905aefd0
RBP: ffffc9000f207b10 R08: ffffffff9057a043 R09: 1ffffffff20af408
R10: dffffc0000000000 R11: fffffbfff20af409 R12: ffff88803ec96cb8
R13: 0000000000000000 R14: 1ffff92001e40f44 R15: 0000000000000000
FS: 00007fe7329916c0(0000) GS:ffff88808c549000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe731b87700 CR3: 000000004374a000 CR4: 0000000000352ef0
Call Trace:
<TASK>
usbg_make_tpg+0x147/0x590 drivers/usb/gadget/function/f_tcm.c:1678
target_fabric_make_tpg+0xa8/0x6d0 drivers/target/target_core_fabric_configfs.c:939
configfs_mkdir+0x4f6/0x9e0 fs/configfs/dir.c:1360
vfs_mkdir+0x406/0x620 fs/namei.c:5276
filename_mkdirat+0x285/0x510 fs/namei.c:5309
__do_sys_mkdir fs/namei.c:5336 [inline]
__se_sys_mkdir+0x34/0x150 fs/namei.c:5333
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe731b9e0d9
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:00007fe732990fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007fe731e25fa0 RCX: 00007fe731b9e0d9
RDX: 0000000000000000 RSI: 00000000000001ff RDI: 0000200000000600
RBP: 00007fe731c35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe731e26038 R14: 00007fe731e25fa0 R15: 00007ffe04766908
</TASK>
----------------
Code disassembly (best guess):
0: a0 57 90 48 c1 e8 03 movabs 0xb60f03e8c1489057,%al
7: 0f b6
9: 04 18 add $0x18,%al
b: 84 c0 test %al,%al
d: 0f 85 47 02 00 00 jne 0x25a
13: 83 3d 45 4e 83 04 00 cmpl $0x0,0x4834e45(%rip) # 0x4834e5f
1a: 75 13 jne 0x2f
1c: 48 8d 3d c8 9d 86 04 lea 0x4869dc8(%rip),%rdi # 0x4869deb
23: 48 c7 c6 40 f7 ec 8b mov $0xffffffff8becf740,%rsi
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: 90 nop
30: e9 75 ee ff ff jmp 0xffffeeaa
35: 90 nop
36: 0f 0b ud2
38: 90 nop
39: e9 48 f2 ff ff jmp 0xfffff286
3e: 90 nop
3f: 0f .byte 0xf
* Struck through repros no longer work on HEAD.