[syzbot] [kernel?] WARNING: ODEBUG bug in vub300_disconnect
From: syzbot
Date: Mon Aug 24 2026 - 21:39:21 EST
Hello,
syzbot found the following issue on:
HEAD commit: 0a0d1d55dad5 Merge tag 'scftorture.2026.08.18a' of git://g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=126be415580000
kernel config: https://syzkaller.appspot.com/x/.config?x=335632b21d0ce540
dashboard link: https://syzkaller.appspot.com/bug?extid=f4a0159ce6802a0a4774
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b00b3ccadcaf/disk-0a0d1d55.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0e672b557a64/vmlinux-0a0d1d55.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b5c1ac823fac/bzImage-0a0d1d55.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f4a0159ce6802a0a4774@xxxxxxxxxxxxxxxxxxxxxxxxx
------------[ cut here ]------------
ODEBUG: free active (active state 0) object: ffff888077279270 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#0: kworker/0:1/10
Modules linked in:
CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
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 5d 6f 4f 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 53 75 92 0b 48 83 c4 10 5b 41 5c
RSP: 0018:ffffc900000f7218 EFLAGS: 00010246
RAX: 1ffffffff181ede4 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: ffffffff8c6d6340 RSI: ffffffff8c6d5dc0 RDI: ffffffff9084da30
RBP: ffffffff8c6d6340 R08: ffff888077279270 R09: ffffffff8c0f8280
R10: dffffc0000000000 R11: ffffffff81b32b80 R12: 0000000000000000
R13: ffffffff9084da30 R14: ffff888077279270 R15: ffffffff8c0f6f20
FS: 0000000000000000(0000) GS:ffff888124cf3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5b6cbceff8 CR3: 000000000eb46000 CR4: 0000000000350ef0
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:2609 [inline]
slab_free mm/slub.c:6372 [inline]
kfree+0x13e/0x640 mm/slub.c:6687
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:458
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:2345
hub_port_connect drivers/usb/core/hub.c:5415 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5715 [inline]
port_event drivers/usb/core/hub.c:5879 [inline]
hub_event+0x1bbb/0x4d30 drivers/usb/core/hub.c:5961
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 5d 6f 4f fd call 0xfd4f6f70
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 53 75 92 0b incl 0xb927553(%rip) # 0xb92758c
39: 48 83 c4 10 add $0x10,%rsp
3d: 5b pop %rbx
3e: 41 5c pop %r12
---
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