syzbot


WARNING: ODEBUG bug in rtl_usb_disconnect

Status: upstream: reported syz repro on 2026/01/04 12:28
Subsystems: usb
[Documentation on labels]
Reported-by: syzbot+7dfaac96168cbf5e949b@syzkaller.appspotmail.com
First crash: 124d, last: 5d17h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [usb?] WARNING: ODEBUG bug in rtl_usb_disconnect 0 (1) 2026/01/04 12:28

Sample crash report:
usb 2-1: USB disconnect, device number 15
------------[ cut here ]------------
ODEBUG: free active (active state 0) object: ffff888125383810 object type: timer_list hint: rtl_ips_nic_off_wq_callback+0x0/0x680 include/linux/etherdevice.h:384
WARNING: lib/debugobjects.c:612 at debug_print_object+0x18e/0x2a0 lib/debugobjects.c:612, CPU#0: kworker/0:6/5947
Modules linked in:
CPU: 0 UID: 0 PID: 5947 Comm: kworker/0:6 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: usb_hub_wq hub_event

RIP: 0010:debug_print_object+0x19b/0x2a0 lib/debugobjects.c:612
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 d2 19 14 08 41 56 48 8b 14 dd e0 84 8a 87 4c 89 e6 <67> 48 0f b9 3a 58 83 05 8c 37 10 08 01 48 83 c4 18 5b 5d 41 5c 41
RSP: 0018:ffffc9000324f3e8 EFLAGS: 00010246

RAX: dffffc0000000000 RBX: 0000000000000003 RCX: 0000000000000000
RDX: ffffffff878a8420 RSI: ffffffff878a8000 RDI: ffffffff8aa880b0
RBP: 0000000000000001 R08: ffff888125383810 R09: ffffffff876b9180
R10: ffffffff8aa491d7 R11: ffff888106f04528 R12: ffffffff878a8000
R13: ffffffff876b91c0 R14: ffffffff845c7cf0 R15: ffffc9000324f4e8
FS:  0000000000000000(0000) GS:ffff888268bf4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055acea04b3e1 CR3: 0000000105f78000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 __debug_check_no_obj_freed lib/debugobjects.c:1099 [inline]
 debug_check_no_obj_freed+0x4b7/0x600 lib/debugobjects.c:1129
 free_pages_prepare mm/page_alloc.c:1402 [inline]
 __free_pages_ok+0x376/0xe10 mm/page_alloc.c:1571
 device_release+0xa4/0x240 drivers/base/core.c:2565
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1ef/0x6f0 lib/kobject.c:737
 put_device+0x1f/0x30 drivers/base/core.c:3797
 rtl_usb_disconnect+0x2b3/0x3a0 drivers/net/wireless/realtek/rtlwifi/usb.c:1077
 usb_unbind_interface+0x1dd/0x9e0 drivers/usb/core/driver.c:458
 device_remove drivers/base/dd.c:571 [inline]
 device_remove+0x125/0x170 drivers/base/dd.c:563
 __device_release_driver drivers/base/dd.c:1282 [inline]
 device_release_driver_internal+0x44b/0x620 drivers/base/dd.c:1305
 bus_remove_device+0x22f/0x450 drivers/base/bus.c:616
 device_del+0x396/0x9f0 drivers/base/core.c:3878
 usb_disable_device+0x355/0x820 drivers/usb/core/message.c:1418
 usb_disconnect+0x2e1/0x9e0 drivers/usb/core/hub.c:2345
 hub_port_connect drivers/usb/core/hub.c:5407 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x1b50/0x5420 drivers/usb/core/hub.c:5953
 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
----------------
Code disassembly (best guess):
   0:	b8 00 00 00 00       	mov    $0x0,%eax
   5:	00 fc                	add    %bh,%ah
   7:	ff                   	(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 d2 19 14 08 	lea    0x81419d2(%rip),%rdi        # 0x81419ef
  1d:	41 56                	push   %r14
  1f:	48 8b 14 dd e0 84 8a 	mov    -0x78757b20(,%rbx,8),%rdx
  26:	87
  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 8c 37 10 08 01 	addl   $0x1,0x810378c(%rip)        # 0x81037c3
  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 (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/04 12:27 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing e46bcc4e856e d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-upstream-usb WARNING: ODEBUG bug in rtl_usb_disconnect
2025/11/29 21:39 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 2585973c7f9e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb WARNING: ODEBUG bug in rtl_usb_disconnect
2025/09/07 22:35 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 6f9871b3e8c3 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb WARNING: ODEBUG bug in rtl_usb_disconnect
* Struck through repros no longer work on HEAD.