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: 5d08h, last: 1d15h
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
5047a518 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ WARNING in usbg_make_tpg 2026/07/28 00:00 2026/07/28 00:00 2026/07/28 00:40 4cb2b096

			
		
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [usb?] WARNING in usbg_make_tpg 0 (1) 2026/07/31 00:12

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.0.0/5324
WARNING: kernel/locking/mutex.c:625 at __mutex_lock+0x12d8/0x1550 kernel/locking/mutex.c:821, CPU#0: syz.0.0/5324
Modules linked in:
CPU: 0 UID: 0 PID: 5324 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: ea 57 90 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 47 02 00 00 83 3d a5 58 83 04 00 75 13 48 8d 3d 08 a8 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:ffffc9000dc97980 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000100000
RDX: ffffc90020001000 RSI: ffffffff8becf740 RDI: ffffffff905b39b0
RBP: ffffc9000dc97b10 R08: ffffffff9057ea43 R09: 1ffffffff20afd48
R10: dffffc0000000000 R11: fffffbfff20afd49 R12: ffff88803fd8e0b8
R13: 0000000000000000 R14: 1ffff92001b92f44 R15: 0000000000000000
FS:  00007f84c61dd6c0(0000) GS:ffff88808c543000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f84c55f26b8 CR3: 000000001fa0b000 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: 0033:0x7f84c539df99
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:00007f84c61dcfe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f84c5626090 RCX: 00007f84c539df99
RDX: 0000000000000000 RSI: 00000000000001ff RDI: 0000200000000600
RBP: 00007f84c5434ec4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f84c5626128 R14: 00007f84c5626090 R15: 00007ffe8ee4d1e8
 </TASK>
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	57                   	push   %rdi
   1:	90                   	nop
   2:	48 c1 e8 03          	shr    $0x3,%rax
   6:	0f b6 04 18          	movzbl (%rax,%rbx,1),%eax
   a:	84 c0                	test   %al,%al
   c:	0f 85 47 02 00 00    	jne    0x259
  12:	83 3d a5 58 83 04 00 	cmpl   $0x0,0x48358a5(%rip)        # 0x48358be
  19:	75 13                	jne    0x2e
  1b:	48 8d 3d 08 a8 86 04 	lea    0x486a808(%rip),%rdi        # 0x486a82a
  22:	48 c7 c6 40 f7 ec 8b 	mov    $0xffffffff8becf740,%rsi
* 29:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2e:	90                   	nop
  2f:	e9 75 ee ff ff       	jmp    0xffffeea9
  34:	90                   	nop
  35:	0f 0b                	ud2
  37:	90                   	nop
  38:	e9 48 f2 ff ff       	jmp    0xfffff285
  3d:	90                   	nop
  3e:	0f                   	.byte 0xf

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/30 14:06 upstream 11028ab62899 0a1bc234 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in usbg_make_tpg
2026/07/26 20:34 upstream 3dab139d4795 492bab15 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING in usbg_make_tpg
* Struck through repros no longer work on HEAD.