[syzbot] [i2c?] [usb?] WARNING: ODEBUG bug in i2c_device_remove (2)

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Apr 20, 2026, 5:36:22 PM (9 hours ago) Apr 20
to linu...@vger.kernel.org, linux-...@vger.kernel.org, linu...@vger.kernel.org, syzkall...@googlegroups.com, wsa+r...@sang-engineering.com
Hello,

syzbot found the following issue on:

HEAD commit: c7275b05bc42 Add linux-next specific files for 20260417
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1782f4ce580000
kernel config: https://syzkaller.appspot.com/x/.config?x=10db2bdce6adb49e
dashboard link: https://syzkaller.appspot.com/bug?extid=019ced393ab913002b75
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10b79906580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16688cf2580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ffefe34549f8/disk-c7275b05.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f679e5d59c0c/vmlinux-c7275b05.xz
kernel image: https://storage.googleapis.com/syzbot-assets/714f96953b57/bzImage-c7275b05.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+019ced...@syzkaller.appspotmail.com

usb 1-1: DVB: registering adapter 1 frontend 0 (Realtek RTL2832 (DVB-T))...
dvbdev: dvb_create_media_entity: media entity 'Realtek RTL2832 (DVB-T)' registered.
DVB: Unable to find symbol r820t_attach()
------------[ cut here ]------------
ODEBUG: free active (active state 0) object: ffff8880258626e8 object type: timer_list hint: rtl2832_i2c_gate_work+0x0/0x100 drivers/media/dvb-frontends/rtl2832.c:-1
WARNING: lib/debugobjects.c:632 at debug_print_object lib/debugobjects.c:629 [inline], CPU#1: kworker/1:2/821
WARNING: lib/debugobjects.c:632 at __debug_check_no_obj_freed lib/debugobjects.c:1116 [inline], CPU#1: kworker/1:2/821
WARNING: lib/debugobjects.c:632 at debug_check_no_obj_freed+0x405/0x550 lib/debugobjects.c:1146, CPU#1: kworker/1:2/821
Modules linked in:
CPU: 1 UID: 0 PID: 821 Comm: kworker/1:2 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:debug_print_object lib/debugobjects.c:629 [inline]
RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:1116 [inline]
RIP: 0010:debug_check_no_obj_freed+0x44a/0x550 lib/debugobjects.c:1146
Code: 89 44 24 20 e8 87 40 6f fd 48 8b 44 24 20 4c 8b 4d 00 4c 89 ef 48 c7 c6 a0 61 ca 8b 48 c7 c2 20 67 ca 8b 8b 0c 24 4d 89 f8 50 <67> 48 0f b9 3a 48 83 c4 08 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc
RSP: 0018:ffffc90004fa67b8 EFLAGS: 00010246
RAX: ffffffff8767dab0 RBX: ffffffff99edac98 RCX: 0000000000000000
RDX: ffffffff8bca6720 RSI: ffffffff8bca61a0 RDI: ffffffff8fd9d990
RBP: ffffffff8b6f5560 R08: ffff8880258626e8 R09: ffffffff8b6f68e0
R10: dffffc0000000000 R11: ffffffff81b15270 R12: ffff888025862800
R13: ffffffff8fd9d990 R14: ffff888025862000 R15: ffff8880258626e8
FS: 0000000000000000(0000) GS:ffff888125b62000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2ec609ae9c CR3: 000000003956c000 CR4: 00000000003526f0
Call Trace:
<TASK>
slab_free_hook mm/slub.c:2620 [inline]
slab_free mm/slub.c:6246 [inline]
kfree+0x13e/0x6c0 mm/slub.c:6561
i2c_device_remove+0x88/0x220 drivers/i2c/i2c-core-base.c:631
device_remove drivers/base/dd.c:619 [inline]
__device_release_driver drivers/base/dd.c:1352 [inline]
device_release_driver_internal+0x46f/0x870 drivers/base/dd.c:1375
bus_remove_device+0x45a/0x570 drivers/base/bus.c:657
device_del+0x52b/0x900 drivers/base/core.c:3895
device_unregister+0x21/0xf0 drivers/base/core.c:3936
rtl28xxu_frontend_detach+0x168/0x210 drivers/media/usb/dvb-usb-v2/rtl28xxu.c:1105
dvb_usbv2_adapter_frontend_exit drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:733 [inline]
dvb_usbv2_adapter_exit drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:830 [inline]
dvb_usbv2_exit+0x44c/0xb80 drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:844
dvb_usbv2_probe+0x4c0/0x3c20 drivers/media/usb/dvb-usb-v2/dvb_usb_core.c:994
usb_probe_interface+0x659/0xc70 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x267/0xaf0 drivers/base/dd.c:709
__driver_probe_device+0x1ef/0x380 drivers/base/dd.c:871
driver_probe_device+0x4f/0x240 drivers/base/dd.c:901
__device_attach_driver+0x279/0x430 drivers/base/dd.c:1029
bus_for_each_drv+0x25b/0x2f0 drivers/base/bus.c:500
__device_attach+0x2c8/0x450 drivers/base/dd.c:1101
device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1156
bus_probe_device+0x12d/0x220 drivers/base/bus.c:613
device_add+0x7e9/0xbb0 drivers/base/core.c:3706
usb_set_configuration+0x1a87/0x2110 drivers/usb/core/message.c:2268
usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
usb_probe_device+0x1c4/0x3b0 drivers/usb/core/driver.c:291
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x267/0xaf0 drivers/base/dd.c:709
__driver_probe_device+0x1ef/0x380 drivers/base/dd.c:871
driver_probe_device+0x4f/0x240 drivers/base/dd.c:901
__device_attach_driver+0x279/0x430 drivers/base/dd.c:1029
bus_for_each_drv+0x25b/0x2f0 drivers/base/bus.c:500
__device_attach+0x2c8/0x450 drivers/base/dd.c:1101
device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1156
bus_probe_device+0x12d/0x220 drivers/base/bus.c:613
device_add+0x7e9/0xbb0 drivers/base/core.c:3706
usb_new_device+0x9f8/0x16e0 drivers/usb/core/hub.c:2695
hub_port_connect drivers/usb/core/hub.c:5567 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x2a49/0x4f60 drivers/usb/core/hub.c:5953
process_one_work+0x9a3/0x1710 kernel/workqueue.c:3312
process_scheduled_works kernel/workqueue.c:3403 [inline]
worker_thread+0xba8/0x11e0 kernel/workqueue.c:3489
kthread+0x388/0x470 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: 89 44 24 20 mov %eax,0x20(%rsp)
4: e8 87 40 6f fd call 0xfd6f4090
9: 48 8b 44 24 20 mov 0x20(%rsp),%rax
e: 4c 8b 4d 00 mov 0x0(%rbp),%r9
12: 4c 89 ef mov %r13,%rdi
15: 48 c7 c6 a0 61 ca 8b mov $0xffffffff8bca61a0,%rsi
1c: 48 c7 c2 20 67 ca 8b mov $0xffffffff8bca6720,%rdx
23: 8b 0c 24 mov (%rsp),%ecx
26: 4d 89 f8 mov %r15,%r8
29: 50 push %rax
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: 48 83 c4 08 add $0x8,%rsp
33: 4c 8b 6c 24 18 mov 0x18(%rsp),%r13
38: 48 rex.W
39: b9 00 00 00 00 mov $0x0,%ecx
3e: 00 fc add %bh,%ah


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