WARNING: ODEBUG bug in snd_rawmidi_free

Status: auto-obsoleted due to no activity on 2026/08/14 00:35
Reported-by: syzbot+0d3945394228cf36bcd6@syzkaller.appspotmail.com
First crash: 289d, last: 118d
Fix bisection: the issue occurs on the latest tested release (bisect log)
Crash: WARNING: ODEBUG bug in corrupted (log)
Repro: C syz .config
  
Bug presence (1)
Date Name Commit Repro Result
2026/08/01 upstream (ToT) 02dc699f83d0 C Failed due to an error; will retry later
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING: ODEBUG bug in snd_rawmidi_free sound usb -1 syz, C error 1 470d 466d 29/29 fixed on 2025/07/08 00:33
Last patch testing requests (5)
Created Duration User Patch Repo Result
2026/08/13 23:21 34m retest repro linux-5.15.y no crash job log log
2026/08/13 23:21 18m retest repro linux-5.15.y no crash job log log
2026/08/13 23:21 19m retest repro linux-5.15.y no crash job log log
2026/07/25 10:02 26m retest repro linux-5.15.y no crash log
2026/06/10 17:42 28m retest repro linux-5.15.y no crash log
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2025/12/05 23:16 2h07m fix candidate upstream OK (0) job log
2025/12/04 13:53 1h58m bisect fix linux-5.15.y OK (0) job log log

Sample crash report:
------------[ cut here ]------------
ODEBUG: free active (active state 0) object type: timer_list hint: snd_usbmidi_error_timer+0x0/0x660
WARNING: CPU: 1 PID: 23 at lib/debugobjects.c:521 debug_print_object lib/debugobjects.c:518 [inline]
WARNING: CPU: 1 PID: 23 at lib/debugobjects.c:521 __debug_check_no_obj_freed lib/debugobjects.c:973 [inline]
WARNING: CPU: 1 PID: 23 at lib/debugobjects.c:521 debug_check_no_obj_freed+0x43c/0x530 lib/debugobjects.c:1003
Modules linked in:
CPU: 1 PID: 23 Comm: kworker/1:1 Not tainted syzkaller #0
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:518 [inline]
RIP: 0010:__debug_check_no_obj_freed lib/debugobjects.c:973 [inline]
RIP: 0010:debug_check_no_obj_freed+0x43c/0x530 lib/debugobjects.c:1003
Code: ef e8 d8 d1 d5 fd 4c 8b 45 00 48 c7 c7 60 07 7a 8a 48 c7 c6 20 04 7a 8a 48 c7 c2 c0 08 7a 8a 8b 0c 24 4d 89 e9 e8 b4 67 c9 05 <0f> 0b 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc ff df ff 05 65 a2 a1
RSP: 0018:ffffc90000ddea18 EFLAGS: 00010246

RAX: 7c188e405a580500 RBX: ffffffff964a5b78 RCX: 0000000000100000
RDX: ffffc900147d9000 RSI: 000000000004e5a7 RDI: 000000000004e5a8
RBP: ffffffff8a2ca8e0 R08: ffff8880b9133d7f R09: 1ffff110172267af
R10: dffffc0000000000 R11: ffffed10172267b0 R12: ffff888020e84400
R13: ffffffff87d09170 R14: ffff888020e84000 R15: ffff888020e84040
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd5b92b3f00 CR3: 00000000255db000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 slab_free_hook mm/slub.c:1685 [inline]
 slab_free_freelist_hook+0x8b/0x170 mm/slub.c:1736
 slab_free mm/slub.c:3504 [inline]
 kfree+0xef/0x2a0 mm/slub.c:4564
 snd_rawmidi_free+0x3b7/0x3e0 sound/core/rawmidi.c:1844
 snd_rawmidi_dev_free+0x34/0x40 sound/core/rawmidi.c:1853
 __snd_device_free+0x1cd/0x2e0 sound/core/device.c:76
 snd_device_free_all+0xcb/0x180 sound/core/device.c:233
 snd_card_do_free sound/core/init.c:588 [inline]
 release_card_device+0x6d/0x1f0 sound/core/init.c:145
 device_release+0x92/0x1c0 drivers/base/core.c:-1
 kobject_cleanup lib/kobject.c:713 [inline]
 kobject_release lib/kobject.c:744 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x21d/0x460 lib/kobject.c:761
 snd_card_free_when_closed sound/core/init.c:620 [inline]
 snd_card_free+0x14b/0x1e0 sound/core/init.c:653
 usb_audio_probe+0x18bd/0x1d90 sound/usb/card.c:939
 usb_probe_interface+0x5c5/0xb20 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x284/0xc80 drivers/base/dd.c:595
 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:785
 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907

Crashes (11):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/21 16:24 linux-5.15.y b9d57c40a767 0b6ab7ec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: ODEBUG bug in snd_rawmidi_free
2026/04/02 10:21 linux-5.15.y 91d48252ad4b 91bc79b0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: ODEBUG bug in snd_rawmidi_free
2026/03/31 21:30 linux-5.15.y 91d48252ad4b fb8b2c26 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: ODEBUG bug in snd_rawmidi_free
2025/12/13 10:30 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: ODEBUG bug in snd_rawmidi_free
2025/12/13 07:58 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: ODEBUG bug in snd_rawmidi_free
2025/12/13 00:44 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: ODEBUG bug in snd_rawmidi_free
2025/12/12 18:46 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: ODEBUG bug in snd_rawmidi_free
2025/12/12 15:08 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: ODEBUG bug in snd_rawmidi_free
2025/12/12 11:20 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: ODEBUG bug in snd_rawmidi_free
2025/12/12 08:40 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: ODEBUG bug in snd_rawmidi_free
2025/11/01 23:03 linux-5.15.y cc5ec8769306 2c50b6a9 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: ODEBUG bug in snd_rawmidi_free
* Struck through repros no longer work on HEAD.