WARNING: ODEBUG bug in gb_operation_sync_timeout

Status: moderation: reported on 2026/10/12 10:02
Subsystems: greybus
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+3412f9f9cd6340803fce@syzkaller.appspotmail.com
First crash: 4d02h, last: 4d02h
▶ ▼ ✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision
d460caa6 repro-c 💥 WARNING: ODEBUG bug in gb_operation_sync_timeout 2026/10/11 04:02 2026/10/11 04:02 2026/10/11 06:18 4f92358f
ea6863f4 assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ WARNING: ODEBUG bug in gb_operation_sync_timeout 2026/10/10 00:00 2026/10/10 00:00 2026/10/10 00:36 549ef7e3

Sample crash report:
greybus greybus1: 0/0:0: synchronous operation id 0x0002 of type 0x10 failed: -71
------------[ cut here ]------------
ODEBUG: free active (active state 0) object: ffff888051a686f0 object type: timer_list hint: gb_operation_timeout+0x0/0x110 drivers/greybus/operation.c:1265
WARNING: lib/debugobjects.c:632 at debug_print_object+0xec/0x230 lib/debugobjects.c:629, CPU#0: kworker/u4:5/77
Modules linked in:
CPU: 0 UID: 0 PID: 77 Comm: kworker/u4:5 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
Workqueue: greybus1:svc gb_svc_process_deferred_request
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 4d af 4c 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 33 d0 8c 0c 48 83 c4 10 5b 41 5c
RSP: 0018:ffffc90000e677e0 EFLAGS: 00010246
RAX: 1ffffffff181f08c RBX: dffffc0000000000 RCX: 0000000000000000
RDX: ffffffff8c6df440 RSI: ffffffff8c6deec0 RDI: ffffffff9185bb80
RBP: ffffffff8c6df440 R08: ffff888051a686f0 R09: ffffffff8c0f97c0
R10: dffffc0000000000 R11: ffffffff81b3f620 R12: 0000000000000000
R13: ffffffff9185bb80 R14: ffff888051a686f0 R15: ffffffff8c0f8460
FS:  0000000000000000(0000) GS:ffff88808b0b4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe02e3f3f98 CR3: 0000000040cb8000 CR4: 0000000000352ef0
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:2679 [inline]
 slab_free mm/slub.c:6509 [inline]
 kmem_cache_free+0xfd/0x650 mm/slub.c:6636
 gb_operation_sync_timeout+0x1c7/0x270 drivers/greybus/operation.c:1172
 gb_operation_sync include/linux/greybus/operation.h:203 [inline]
 gb_svc_intf_set_power_mode drivers/greybus/svc.c:584 [inline]
 gb_svc_process_hello_deferred drivers/greybus/svc.c:936 [inline]
 gb_svc_process_deferred_request+0x5f3/0x1150 drivers/greybus/svc.c:1102
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
 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 4d af 4c fd       	call   0xfd4caf60
  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 33 d0 8c 0c    	incl   0xc8cd033(%rip)        # 0xc8cd06c
  39:	48 83 c4 10          	add    $0x10,%rsp
  3d:	5b                   	pop    %rbx
  3e:	41 5c                	pop    %r12

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/08 09:55 upstream 7b63ef2d55f2 4f6a9fcf .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING: ODEBUG bug in gb_operation_sync_timeout
* Struck through repros no longer work on HEAD.