[syzbot] [net?] WARNING: ODEBUG bug in lane_ioctl (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: e728258debd5 Merge tag 'net-7.1-rc1' of git://git.kernel.o..
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1752f702580000
kernel config: https://syzkaller.appspot.com/x/.config?x=ca77bfc4078c8193
dashboard link: https://syzkaller.appspot.com/bug?extid=ca9d5686d06994c6547c
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=16811c36580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=128c52d2580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/24195bde5d1d/disk-e728258d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/78131d1b0e14/vmlinux-e728258d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/836d0dd78c10/bzImage-e728258d.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ca9d56...@syzkaller.appspotmail.com

------------[ cut here ]------------
ODEBUG: init active (active state 0) object: ffff888077a60f78 object type: timer_list hint: lec_arp_check_expire+0x0/0xc90 net/atm/lec.c:-1
WARNING: lib/debugobjects.c:632 at debug_print_object lib/debugobjects.c:629 [inline], CPU#0: syz-executor253/5933
WARNING: lib/debugobjects.c:632 at __debug_object_init+0x2b1/0x4e0 lib/debugobjects.c:780, CPU#0: syz-executor253/5933
Modules linked in:
CPU: 0 UID: 0 PID: 5933 Comm: syz-executor253 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:debug_print_object lib/debugobjects.c:629 [inline]
RIP: 0010:__debug_object_init+0x30f/0x4e0 lib/debugobjects.c:780
Code: 3c 38 00 74 08 4c 89 ef e8 0e df 74 fd 4d 8b 4d 00 4c 89 f7 48 c7 c6 20 a7 28 8c 4c 89 e2 8b 4c 24 08 4c 8b 04 24 ff 74 24 10 <67> 48 0f b9 3a 48 83 c4 08 ff 05 8e 8c 77 0b 83 fd 03 75 3f 4c 8b
RSP: 0018:ffffc90003e278f8 EFLAGS: 00010246
RAX: 1ffffffff179e734 RBX: ffff888077a60f78 RCX: 0000000000000000
RDX: ffffffff8c28ab20 RSI: ffffffff8c28a720 RDI: ffffffff903e69a0
RBP: 0000000000000003 R08: ffff888077a60f78 R09: ffffffff8bcf4d00
R10: dffffc0000000000 R11: ffffffff81b236d0 R12: ffffffff8c28ab20
R13: ffffffff8bcf39a0 R14: ffffffff903e69a0 R15: dffffc0000000000
FS: 00007f3e1e8976c0(0000) GS:ffff888125213000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a602110fd8 CR3: 00000000753ea000 CR4: 00000000003526f0
Call Trace:
<TASK>
debug_timer_init kernel/time/timer.c:788 [inline]
debug_init kernel/time/timer.c:836 [inline]
timer_init_key+0x41/0x2c0 kernel/time/timer.c:880
lec_arp_init net/atm/lec.c:1274 [inline]
lecd_attach net/atm/lec.c:781 [inline]
lane_ioctl+0x1579/0x2220 net/atm/lec.c:1037
do_vcc_ioctl+0x36d/0x9d0 net/atm/ioctl.c:159
svc_ioctl+0x1f6/0x7d0 net/atm/svc.c:611
sock_do_ioctl+0x101/0x320 net/socket.c:1313
sock_ioctl+0x5c6/0x7f0 net/socket.c:1434
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3e1e8bf0d9
Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 d0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3e1e897158 EFLAGS: 00000246
ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f3e1e96fb48 RCX: 00007f3e1e8bf0d9
RDX: 0000000000000000 RSI: 00000000000061d0 RDI: 0000000000000005
RBP: 00007f3e1e96fb40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3e1e9413b0
R13: 0000000000000000 R14: 0000200000000040 R15: b635773f07ebbeef
</TASK>
----------------
Code disassembly (best guess):
0: 3c 38 cmp $0x38,%al
2: 00 74 08 4c add %dh,0x4c(%rax,%rcx,1)
6: 89 ef mov %ebp,%edi
8: e8 0e df 74 fd call 0xfd74df1b
d: 4d 8b 4d 00 mov 0x0(%r13),%r9
11: 4c 89 f7 mov %r14,%rdi
14: 48 c7 c6 20 a7 28 8c mov $0xffffffff8c28a720,%rsi
1b: 4c 89 e2 mov %r12,%rdx
1e: 8b 4c 24 08 mov 0x8(%rsp),%ecx
22: 4c 8b 04 24 mov (%rsp),%r8
26: ff 74 24 10 push 0x10(%rsp)
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: 48 83 c4 08 add $0x8,%rsp
33: ff 05 8e 8c 77 0b incl 0xb778c8e(%rip) # 0xb778cc7
39: 83 fd 03 cmp $0x3,%ebp
3c: 75 3f jne 0x7d
3e: 4c rex.WR
3f: 8b .byte 0x8b


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