WARNING: ODEBUG bug in get

WARNING: ODEBUG bug in get_signal
Status: upstream: reported on 2020/09/05 14:38
Reported-by: syzbot+e16c01cde30a5e26f712@syzkaller.appspotmail.com
First crash: 53d, last: 53d

similar bugs (2):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	WARNING: ODEBUG bug in get_signal	syz	done	unreliable	9	54d	62d	0/17	upstream: reported syz repro on 2020/08/27 07:58
linux-4.19	WARNING: ODEBUG bug in get_signal	syz		done	3	52d	62d	1/1	fixed on 2020/10/07 06:25

Sample crash report:

ODEBUG: free active (active state 1) object type: rcu_head hint:           (null)
------------[ cut here ]------------
WARNING: CPU: 0 PID: 16189 at lib/debugobjects.c:287 debug_print_object.cold+0xa7/0xdb lib/debugobjects.c:287
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 16189 Comm: syz-executor.4 Not tainted 4.14.196-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x283 lib/dump_stack.c:58
 panic+0x1f9/0x42d kernel/panic.c:183
 __warn.cold+0x20/0x4b kernel/panic.c:547
 report_bug+0x208/0x249 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 fixup_bug arch/x86/kernel/traps.c:172 [inline]
 do_error_trap+0x195/0x2d0 arch/x86/kernel/traps.c:295
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:964
RIP: 0010:debug_print_object.cold+0xa7/0xdb lib/debugobjects.c:287
RSP: 0018:ffff88805138fab0 EFLAGS: 00010086
RAX: 0000000000000051 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 000000000002acdf RSI: ffffffff814a4600 RDI: ffffed100a271f4c
RBP: ffffffff86ab6440 R08: 0000000000000051 R09: 0000000000000000
R10: 0000000000000000 R11: ffff888046a7c080 R12: 0000000000000000
R13: 0000000000000001 R14: ffff888096fe2c80 R15: ffff88809209e738
 __debug_check_no_obj_freed lib/debugobjects.c:747 [inline]
 debug_check_no_obj_freed+0x3b7/0x674 lib/debugobjects.c:776
 kmem_cache_free+0x156/0x2b0 mm/slab.c:3757
 task_work_run+0x11f/0x190 kernel/task_work.c:113
 get_signal+0x18a3/0x1ca0 kernel/signal.c:2234
 do_signal+0x7c/0x1550 arch/x86/kernel/signal.c:814
 exit_to_usermode_loop+0x160/0x200 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45d5b9
RSP: 002b:00007f53721a1c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000e9
RAX: 0000000000000000 RBX: 0000000000002ac0 RCX: 000000000045d5b9
RDX: 0000000000000005 RSI: 0000000000000001 RDI: 0000000000000006
RBP: 000000000118d028 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020000340 R11: 0000000000000246 R12: 000000000118cfec
R13: 00007ffcfa81465f R14: 00007f53721a29c0 R15: 000000000118cfec

======================================================

Crashes (1):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Maintainers
ci2-linux-4-14	2020/09/05 14:37	linux-4.14.y	2f166cdc	abf9ba4f	.config	log	report				akpm@linux-foundation.org, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, mingo@kernel.org, oleg@redhat.com, viro@zeniv.linux.org.uk