syzbot


WARNING: ODEBUG bug in handle_softirqs

Status: upstream: reported on 2026/02/04 17:13
Reported-by: syzbot+84f4fd5aada92779a9f1@syzkaller.appspotmail.com
First crash: 9d14h, last: 8d18h
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 WARNING: ODEBUG bug in handle_softirqs -1 2 16d 18d 0/2 upstream: reported on 2026/01/26 16:28
upstream WARNING: ODEBUG bug in handle_softirqs hams -1 C 1973 2h00m 170d 0/29 upstream: reported C repro on 2025/08/27 17:00

Sample crash report:
------------[ cut here ]------------
ODEBUG: free active (active state 0) object type: timer_list hint: br_ip6_multicast_port_query_expired+0x0/0x20
WARNING: CPU: 1 PID: 21 at lib/debugobjects.c:518 debug_print_object lib/debugobjects.c:515 [inline]
WARNING: CPU: 1 PID: 21 at lib/debugobjects.c:518 __debug_check_no_obj_freed lib/debugobjects.c:979 [inline]
WARNING: CPU: 1 PID: 21 at lib/debugobjects.c:518 debug_check_no_obj_freed+0x43c/0x530 lib/debugobjects.c:1009
Modules linked in:
CPU: 1 PID: 21 Comm: ksoftirqd/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:debug_print_object lib/debugobjects.c:515 [inline]
RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:979 [inline]
RIP: 0010:debug_check_no_obj_freed+0x43c/0x530 lib/debugobjects.c:1009
Code: ef e8 18 00 be fd 4c 8b 45 00 48 c7 c7 80 15 df 8a 48 c7 c6 40 12 df 8a 48 c7 c2 e0 16 df 8a 8b 0c 24 4d 89 e9 e8 54 87 38 fd <0f> 0b 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc ff df ff 05 85 9a 0a
RSP: 0018:ffffc900001b78b8 EFLAGS: 00010246
RAX: 1681990ca6784200 RBX: ffffffff96ea0e08 RCX: ffff888017751dc0
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffffffff8a8def40 R08: ffffc900001b7547 R09: 1ffff92000036ea8
R10: dffffc0000000000 R11: fffff52000036ea9 R12: ffff888054ba1c00
R13: ffffffff8913ce30 R14: ffff888054ba1000 R15: ffff888054ba1a78
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 0000000065042000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 slab_free_hook mm/slub.c:1704 [inline]
 slab_free_freelist_hook+0xd2/0x1a0 mm/slub.c:1755
 slab_free mm/slub.c:3687 [inline]
 __kmem_cache_free+0xb6/0x1f0 mm/slub.c:3700
 kobject_cleanup lib/kobject.c:681 [inline]
 kobject_release lib/kobject.c:712 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x21d/0x460 lib/kobject.c:729
 rcu_do_batch kernel/rcu/tree.c:2297 [inline]
 rcu_core+0xa99/0x1740 kernel/rcu/tree.c:2557
 handle_softirqs+0x2a1/0x930 kernel/softirq.c:596
 run_ksoftirqd+0xa4/0x100 kernel/softirq.c:968
 smpboot_thread_fn+0x64a/0xa40 kernel/smpboot.c:164
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/05 13:07 linux-6.1.y cd9b81672742 4936e85c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING: ODEBUG bug in handle_softirqs
2026/02/05 13:05 linux-6.1.y cd9b81672742 4936e85c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING: ODEBUG bug in handle_softirqs
2026/02/04 17:14 linux-6.1.y cd9b81672742 ea10c935 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING: ODEBUG bug in handle_softirqs
2026/02/04 17:12 linux-6.1.y cd9b81672742 ea10c935 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING: ODEBUG bug in handle_softirqs
* Struck through repros no longer work on HEAD.