syzbot


WARNING: ODEBUG bug in __sk_destruct

Status: upstream: reported C repro on 2025/08/02 18:15
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+49b2d54a43d3c362f038@syzkaller.appspotmail.com
First crash: 34d, last: 32d
Bug presence (1)
Date Name Commit Repro Result
2025/08/03 upstream (ToT) 186f3edfdd41 C [report] KASAN: slab-use-after-free Read in __lock_sock
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING: ODEBUG bug in __sk_destruct origin:upstream -1 C 2 7d18h 44d 0/3 upstream: reported C repro on 2025/07/23 20:40
upstream WARNING: ODEBUG bug in __sk_destruct smc -1 C 2855 2221d 2686d 12/29 fixed on 2019/08/27 17:15
linux-6.6 WARNING: ODEBUG bug in __sk_destruct origin:upstream missing-backport -1 C 3 21h42m 48d 0/2 upstream: reported C repro on 2025/07/19 04:11
upstream WARNING: ODEBUG bug in __sk_destruct (3) net -1 C error 12 12d 28d 26/29 upstream: reported C repro on 2025/08/08 11:24
upstream WARNING: ODEBUG bug in __sk_destruct (2) can -1 C done done 62 1405d 1603d 20/29 fixed on 2021/11/10 00:50

Sample crash report:
------------[ cut here ]------------
ODEBUG: free active (active state 0) object type: work_struct hint: kcm_tx_work+0x0/0x180
WARNING: CPU: 0 PID: 4547 at lib/debugobjects.c:518 debug_print_object lib/debugobjects.c:515 [inline]
WARNING: CPU: 0 PID: 4547 at lib/debugobjects.c:518 __debug_check_no_obj_freed lib/debugobjects.c:979 [inline]
WARNING: CPU: 0 PID: 4547 at lib/debugobjects.c:518 debug_check_no_obj_freed+0x43c/0x530 lib/debugobjects.c:1009
Modules linked in:
CPU: 0 PID: 4547 Comm: syz.3.27 Not tainted 6.1.147-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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 e8 fd c5 fd 4c 8b 45 00 48 c7 c7 80 fc de 8a 48 c7 c6 40 f9 de 8a 48 c7 c2 e0 fd de 8a 8b 0c 24 4d 89 e9 e8 84 03 42 fd <0f> 0b 4c 8b 6c 24 18 48 b9 00 00 00 00 00 fc ff df ff 05 d5 9a 14
RSP: 0018:ffffc90003897b50 EFLAGS: 00010246
RAX: eac82f45b1d62300 RBX: ffffffff96ea6cd0 RCX: ffff888030a85940
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffffffff8a8b3700 R08: dffffc0000000000 R09: fffffbfff215ba5c
R10: fffffbfff215ba5c R11: 1ffffffff215ba5b R12: ffff88805b033238
R13: ffffffff894df300 R14: ffff88805b033000 R15: ffff88805b033120
FS:  00007f2c0b1d36c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3d20e71d58 CR3: 000000007a444000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 slab_free_hook mm/slub.c:1699 [inline]
 slab_free_freelist_hook+0xd2/0x1a0 mm/slub.c:1750
 slab_free mm/slub.c:3661 [inline]
 kmem_cache_free+0xf7/0x290 mm/slub.c:3683
 sk_prot_free net/core/sock.c:2084 [inline]
 __sk_destruct+0x48d/0x630 net/core/sock.c:2172
 kcm_release+0x520/0x5b0 net/kcm/kcmsock.c:1860
 __sock_release net/socket.c:654 [inline]
 sock_close+0xd5/0x240 net/socket.c:1400
 __fput+0x22c/0x920 fs/file_table.c:320
 task_work_run+0x1ca/0x250 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2c0a38eb69
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2c0b1d3038 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 00007f2c0a5b6160 RCX: 00007f2c0a38eb69
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 00007f2c0a411df1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f2c0a5b6160 R15: 00007fff7ddcad68
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/04 00:38 linux-6.1.y 3594f306da12 7368264b .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING: ODEBUG bug in __sk_destruct
2025/08/03 14:30 linux-6.1.y 3594f306da12 7368264b .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING: ODEBUG bug in __sk_destruct
2025/08/02 18:15 linux-6.1.y 3594f306da12 7368264b .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING: ODEBUG bug in __sk_destruct
* Struck through repros no longer work on HEAD.