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: 21d, last: 2d02h
✨ 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 2 1d07h 19d 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: ffff888033c81270 object type: timer_list hint: vub300_inactivity_timer_expired+0x0/0x550 drivers/mmc/host/vub300.c:1447
WARNING: lib/debugobjects.c:629 at debug_print_object+0x198/0x2b0 lib/debugobjects.c:629, CPU#1: kworker/1:1/31
Modules linked in:
CPU: 1 UID: 0 PID: 31 Comm: kworker/1:1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:debug_print_object+0x1a5/0x2b0 lib/debugobjects.c:629
Code: b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 4f 48 8d 3d 78 19 1c 0c 41 56 48 8b 14 ed 40 20 62 8c 4c 89 e6 <67> 48 0f b9 3a 58 83 05 22 77 11 0c 01 48 83 c4 18 5b 5d 41 5c 41
RSP: 0018:ffffc90000a773c8 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffffc90000a774b0 RCX: 0000000000000000
RDX: ffffffff8c621f80 RSI: ffffffff8c621b20 RDI: ffffffff914fd650
RBP: 0000000000000003 R08: ffff888033c81270 R09: ffffffff8bf30fc0
R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff8c621b20
R13: ffffffff8bf31000 R14: ffffffff88c8ce70 R15: ffffc90000a774c8
FS:  0000000000000000(0000) GS:ffff888123c60000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000054c0 CR3: 000000005d5c1000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __debug_check_no_obj_freed lib/debugobjects.c:1171 [inline]
 debug_check_no_obj_freed+0x4da/0x630 lib/debugobjects.c:1201
 slab_free_hook mm/slub.c:2679 [inline]
 slab_free mm/slub.c:6499 [inline]
 kfree+0x3d6/0x6d0 mm/slub.c:6792
 device_release+0xd2/0x270 drivers/base/core.c:2640
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1f7/0x640 lib/kobject.c:737
 put_device+0x1f/0x30 drivers/base/core.c:3884
 vub300_delete drivers/mmc/host/vub300.c:379 [inline]
 kref_put.constprop.0.isra.0+0x159/0x1d0 include/linux/kref.h:65
 vub300_disconnect+0x136/0x170 drivers/mmc/host/vub300.c:2388
 usb_unbind_interface+0x1dd/0x9e0 drivers/usb/core/driver.c:461
 device_remove drivers/base/dd.c:618 [inline]
 device_remove+0x12a/0x180 drivers/base/dd.c:610
 __device_release_driver drivers/base/dd.c:1349 [inline]
 device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1372
 bus_remove_device+0x2bc/0x560 drivers/base/bus.c:664
 device_del+0x376/0x9b0 drivers/base/core.c:3965
 usb_disable_device+0x367/0x810 drivers/usb/core/message.c:1478
 usb_disconnect+0x2e2/0x9a0 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+0x1bb1/0x4420 drivers/usb/core/hub.c:5966
 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396
 process_scheduled_works kernel/workqueue.c:3479 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 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:	b8 00 00 00 00       	mov    $0x0,%eax
   5:	00 fc                	add    %bh,%ah
   7:	ff                   	lcall  (bad)
   8:	df 48 89             	fisttps -0x77(%rax)
   b:	fa                   	cli
   c:	48 c1 ea 03          	shr    $0x3,%rdx
  10:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
  14:	75 4f                	jne    0x65
  16:	48 8d 3d 78 19 1c 0c 	lea    0xc1c1978(%rip),%rdi        # 0xc1c1995
  1d:	41 56                	push   %r14
  1f:	48 8b 14 ed 40 20 62 	mov    -0x739ddfc0(,%rbp,8),%rdx
  26:	8c
  27:	4c 89 e6             	mov    %r12,%rsi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	58                   	pop    %rax
  30:	83 05 22 77 11 0c 01 	addl   $0x1,0xc117722(%rip)        # 0xc117759
  37:	48 83 c4 18          	add    $0x18,%rsp
  3b:	5b                   	pop    %rbx
  3c:	5d                   	pop    %rbp
  3d:	41 5c                	pop    %r12
  3f:	41                   	rex.B

Crashes (13):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/04 09:12 upstream 841e384b841a 801f0966 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING: ODEBUG bug in vub300_disconnect
2026/09/02 04:27 upstream 786262be6048 587f6b29 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING: ODEBUG bug in vub300_disconnect
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
2026/09/02 10:05 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing edc1518454f6 587f6b29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb WARNING: ODEBUG bug in vub300_disconnect
2026/08/30 05:28 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb WARNING: ODEBUG bug in vub300_disconnect
2026/08/30 00:08 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb WARNING: ODEBUG bug in vub300_disconnect
2026/08/29 15:44 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb WARNING: ODEBUG bug in vub300_disconnect
* Struck through repros no longer work on HEAD.