WARNING: ODEBUG bug in vub300_disconnect

Status: upstream: reported on 2026/08/25 01:37
Subsystems: kernel
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+f4a0159ce6802a0a4774@syzkaller.appspotmail.com
First crash: 12d, last: 1d07h
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision
fb965b11 repro-c Reproduced: ✅ WARNING: ODEBUG bug in vub300_disconnect 2026/08/26 18:29 2026/08/26 20:52 2026/08/26 23:41 a2b77b9e
2e9da764 assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ WARNING: ODEBUG bug in vub300_disconnect 2026/08/18 00:08 2026/08/18 00:08 2026/08/18 00:11 1e72964b
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [kernel?] WARNING: ODEBUG bug in vub300_disconnect 0 (1) 2026/08/25 01:37
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING: ODEBUG bug in vub300_disconnect -1 1 11d 11d 0/3 upstream: reported on 2026/08/17 19:21
Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/08/27 07:33 59m nogikh@google.com git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 818bebeb63dd6bf5f4e07e145f6cdbace520a34c report job log log

Sample crash report:
------------[ cut here ]------------
ODEBUG: free active (active state 0) object: ffff8880330c1270 object type: timer_list hint: vub300_inactivity_timer_expired+0x0/0x3f0 include/linux/refcount.h:-1
WARNING: lib/debugobjects.c:632 at debug_print_object+0xec/0x230 lib/debugobjects.c:629, CPU#1: kworker/1:10/5891
Modules linked in:
CPU: 1 UID: 0 PID: 5891 Comm: kworker/1:10 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:debug_print_object+0x18a/0x230 lib/debugobjects.c:629
Code: f8 48 c1 e8 03 80 3c 18 00 74 08 4c 89 ff e8 1d 91 4e fd 4d 8b 0f 4c 89 ef 48 8b 74 24 08 48 89 ea 44 89 e1 4d 89 f0 ff 34 24 <67> 48 0f b9 3a 48 83 c4 08 ff 05 d3 8d 91 0b 48 83 c4 10 5b 41 5c
RSP: 0018:ffffc9000530f218 EFLAGS: 00010246
RAX: 1ffffffff181f01c RBX: dffffc0000000000 RCX: 0000000000000000
RDX: ffffffff8c6d9040 RSI: ffffffff8c6d8ac0 RDI: ffffffff90854f90
RBP: ffffffff8c6d9040 R08: ffff8880330c1270 R09: ffffffff8c0f9440
R10: dffffc0000000000 R11: ffffffff81b3a0c0 R12: 0000000000000000
R13: ffffffff90854f90 R14: ffff8880330c1270 R15: ffffffff8c0f80e0
FS:  0000000000000000(0000) GS:ffff888124de0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6cd17f7fe0 CR3: 00000000335ba000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000063235cd5
DR3: 0000000000007000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __debug_check_no_obj_freed lib/debugobjects.c:1171 [inline]
 debug_check_no_obj_freed+0x2e3/0x450 lib/debugobjects.c:1201
 slab_free_hook mm/slub.c:2679 [inline]
 slab_free mm/slub.c:6499 [inline]
 kfree+0x13e/0x650 mm/slub.c:6792
 device_release+0xc4/0x1f0 drivers/base/core.c:-1
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x222/0x550 lib/kobject.c:737
 vub300_delete drivers/mmc/host/vub300.c:379 [inline]
 kref_put include/linux/kref.h:65 [inline]
 vub300_disconnect+0x280/0x2f0 drivers/mmc/host/vub300.c:2388
 usb_unbind_interface+0x295/0x9f0 drivers/usb/core/driver.c:461
 device_remove drivers/base/dd.c:618 [inline]
 __device_release_driver drivers/base/dd.c:1349 [inline]
 device_release_driver_internal+0x4f5/0x880 drivers/base/dd.c:1372
 bus_remove_device+0x444/0x560 drivers/base/bus.c:664
 device_del+0x524/0x8f0 drivers/base/core.c:3965
 usb_disable_device+0x3d4/0x8d0 drivers/usb/core/message.c:1478
 usb_disconnect+0x346/0x9a0 drivers/usb/core/hub.c:2350
 hub_port_connect drivers/usb/core/hub.c:5420 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5720 [inline]
 port_event drivers/usb/core/hub.c:5884 [inline]
 hub_event+0x1bbb/0x4d30 drivers/usb/core/hub.c:5966
 process_one_work kernel/workqueue.c:3387 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3470
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3551
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
----------------
Code disassembly (best guess):
   0:	f8                   	clc
   1:	48 c1 e8 03          	shr    $0x3,%rax
   5:	80 3c 18 00          	cmpb   $0x0,(%rax,%rbx,1)
   9:	74 08                	je     0x13
   b:	4c 89 ff             	mov    %r15,%rdi
   e:	e8 1d 91 4e fd       	call   0xfd4e9130
  13:	4d 8b 0f             	mov    (%r15),%r9
  16:	4c 89 ef             	mov    %r13,%rdi
  19:	48 8b 74 24 08       	mov    0x8(%rsp),%rsi
  1e:	48 89 ea             	mov    %rbp,%rdx
  21:	44 89 e1             	mov    %r12d,%ecx
  24:	4d 89 f0             	mov    %r14,%r8
  27:	ff 34 24             	push   (%rsp)
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	48 83 c4 08          	add    $0x8,%rsp
  33:	ff 05 d3 8d 91 0b    	incl   0xb918dd3(%rip)        # 0xb918e0c
  39:	48 83 c4 10          	add    $0x10,%rsp
  3d:	5b                   	pop    %rbx
  3e:	41 5c                	pop    %r12

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/27 13:26 upstream 73e3f0710014 a2b77b9e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: ODEBUG bug in vub300_disconnect
2026/08/25 06:44 upstream 66498c75b4f8 23caa175 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING: ODEBUG bug in vub300_disconnect
2026/08/25 01:36 upstream 0a0d1d55dad5 23caa175 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: ODEBUG bug in vub300_disconnect
2026/08/19 05:47 upstream 0f23d56f17fd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: ODEBUG bug in vub300_disconnect
2026/08/18 13:32 upstream ff68e5f557f6 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING: ODEBUG bug in vub300_disconnect
2026/08/16 11:28 upstream 3eb40771c00a 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING: ODEBUG bug in vub300_disconnect
2026/08/16 07:57 upstream 3eb40771c00a 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING: ODEBUG bug in vub300_disconnect
* Struck through repros no longer work on HEAD.