From: syzbot <syzbot+06ec7624018233e17113@syzkaller.appspotmail.com>
To: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: [syzbot] [kernel?] WARNING: kobject bug in goku_remove
Date: Thu, 13 Aug 2026 13:45:28 -0700 [thread overview]
Message-ID: <6a7e2ce8.f70deec7.2acc03.000c.GAE@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: 3aa1dcaa4f6f Revert "wifi: mt76: Disable napi when removin..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11e09c79580000
kernel config: https://syzkaller.appspot.com/x/.config?x=c44651ea7dd2f307
dashboard link: https://syzkaller.appspot.com/bug?extid=06ec7624018233e17113
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=160e4ac6580000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+06ec7624018233e17113@syzkaller.appspotmail.com
usb usb3: USB disconnect, device number 1
uhci_hcd 0000:00:1d.1: USB bus 3 deregistered
------------[ cut here ]------------
kobject: '(null)' (ffff8880281480d8): is not initialized, yet kobject_put() is being called.
WARNING: lib/kobject.c:734 at kobject_put+0x252/0x640 lib/kobject.c:734, CPU#2: syz-executor405/6027
Modules linked in:
CPU: 2 UID: 0 PID: 6027 Comm: syz-executor405 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:kobject_put+0x258/0x640 lib/kobject.c:734
Code: 59 f6 48 89 da 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 5e 03 00 00 48 8d 3d 9e 2d 83 05 48 8b 33 48 89 da <67> 48 0f b9 3a e9 0b fe ff ff e8 b9 88 59 f6 be 03 00 00 00 4c 89
RSP: 0018:ffffc90003437728 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff8880281480d8 RCX: ffffffff8bb0e8c4
RDX: ffff8880281480d8 RSI: 0000000000000000 RDI: ffffffff91341850
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888028148114
R13: dffffc0000000000 R14: ffff888028148834 R15: 0000000000000000
FS: 0000555585cdf400(0000) GS:ffff8880d5fe9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe6f14cda8 CR3: 0000000055370000 CR4: 0000000000352ef0
Call Trace:
<TASK>
put_device+0x1f/0x30 drivers/base/core.c:3880
goku_remove+0x47/0x470 drivers/usb/gadget/udc/goku_udc.c:1717
goku_probe+0x2f6/0x3c0 drivers/usb/gadget/udc/goku_udc.c:1830
local_pci_probe+0xdd/0x1b0 drivers/pci/pci-driver.c:332
pci_call_probe+0x176/0x800 drivers/pci/pci-driver.c:394
__pci_device_probe drivers/pci/pci-driver.c:455 [inline]
pci_device_probe+0x1cd/0x370 drivers/pci/pci-driver.c:489
call_driver_probe drivers/base/dd.c:628 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:706
__driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
__driver_attach+0x21f/0x5b0 drivers/base/dd.c:1292
bus_for_each_dev+0x13e/0x1d0 drivers/base/bus.c:383
pci_add_dynid+0x2b5/0x370 drivers/pci/pci-driver.c:77
new_id_store+0x2a9/0x5b0 drivers/pci/pci-driver.c:249
drv_attr_store+0x74/0xb0 drivers/base/bus.c:125
sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x6ac/0x1050 fs/read_write.c:687
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f370300ce37
Code: 48 89 fa 4c 89 df e8 98 1d 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007fff6fddcbc0 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000555585cdf400 RCX: 00007f370300ce37
RDX: 000000000000000d RSI: 00007fff6fddcc80 RDI: 0000000000000003
RBP: 00007fff6fddd400 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003
R13: 00007fff6fddcf20 R14: 00007fff6fddcd00 R15: 000000000000000a
</TASK>
----------------
Code disassembly (best guess):
0: 59 pop %rcx
1: f6 48 89 da testb $0xda,-0x77(%rax)
5: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
c: fc ff df
f: 48 c1 ea 03 shr $0x3,%rdx
13: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1)
17: 0f 85 5e 03 00 00 jne 0x37b
1d: 48 8d 3d 9e 2d 83 05 lea 0x5832d9e(%rip),%rdi # 0x5832dc2
24: 48 8b 33 mov (%rbx),%rsi
27: 48 89 da mov %rbx,%rdx
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: e9 0b fe ff ff jmp 0xfffffe3f
34: e8 b9 88 59 f6 call 0xf65988f2
39: be 03 00 00 00 mov $0x3,%esi
3e: 4c rex.WR
3f: 89 .byte 0x89
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
reply other threads:[~2026-08-13 20:45 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=6a7e2ce8.f70deec7.2acc03.000c.GAE@google.com \
--to=syzbot+06ec7624018233e17113@syzkaller.appspotmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=syzkaller-bugs@googlegroups.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.