general protection fault in _

general protection fault in __bfs
Status: upstream: reported on 2020/10/19 10:38
Reported-by: syzbot+801cbece6e387313f191@syzkaller.appspotmail.com
First crash: 140d, last: 25d

similar bugs (2):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	general protection fault in __bfs	C			4	789d	817d	0/21	closed as dup on 2018/12/12 11:02
upstream	general protection fault in __bfs (2)	C	done	done	16	296d	776d	0/21	upstream: reported C repro on 2019/01/22 18:23

Sample crash report:

RBP: 00007fdc23bd91d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff8bd9831f R14: 00007fdc23bd9300 R15: 0000000000022000
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 23 Comm: kworker/1:1 Not tainted 4.14.218-syzkaller #0
overlayfs: fs on 'file0' does not support file handles, falling back to index=off.
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events l2cap_chan_timeout
task: ffff8880b5602600 task.stack: ffff8880b5608000
RIP: 0010:lock_accessed syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:979 [inline]
RIP: 0010:__bfs.part.0+0x20e/0x470 syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:1045
RSP: 0018:ffff8880b560f808 EFLAGS: 00010007
RAX: 0000000001d0e3d7 RBX: ffffffff8bb05860 RCX: 0000000000000000
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000010
overlayfs: unrecognized mount option "lowerd" or missing value
RBP: ffff8880b560f8c0 R08: 0000000000000000 R09: 000000000000349a
R10: 0000000000145f85 R11: 0000000000066071 R12: ffffffff8140da10
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe16f333f80 CR3: 000000005c2cf000 CR4: 00000000001426e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
overlayfs: fs on 'file0' does not support file handles, falling back to index=off.
 __bfs syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:1424 [inline]
 __bfs_backwards syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:1082 [inline]
 find_usage_backwards syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:1424 [inline]
 check_usage_backwards+0x167/0x2c0 syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:2713
overlayfs: unrecognized mount option "lowerd" or missing value
 mark_lock_irq syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:2804 [inline]
 mark_lock+0x3c7/0x1050 syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:3194
 mark_irqflags syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:3086 [inline]
 __lock_acquire+0xcf9/0x3f20 syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:3448
 lock_acquire+0x170/0x3f0 syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:3998
 __raw_spin_lock_bh syzkaller/managers/linux-4-14/kernel/./include/linux/spinlock_api_smp.h:135 [inline]
 _raw_spin_lock_bh+0x2f/0x40 syzkaller/managers/linux-4-14/kernel/kernel/locking/spinlock.c:176
 spin_lock_bh syzkaller/managers/linux-4-14/kernel/./include/linux/spinlock.h:322 [inline]
 lock_sock_nested+0x39/0x100 syzkaller/managers/linux-4-14/kernel/net/core/sock.c:2788
 l2cap_sock_teardown_cb+0x93/0x650 syzkaller/managers/linux-4-14/kernel/net/bluetooth/l2cap_sock.c:1341
 l2cap_chan_del+0xaf/0x950 syzkaller/managers/linux-4-14/kernel/net/bluetooth/l2cap_core.c:599
 l2cap_chan_close+0x103/0x870 syzkaller/managers/linux-4-14/kernel/net/bluetooth/l2cap_core.c:757
 l2cap_chan_timeout+0x143/0x2a0 syzkaller/managers/linux-4-14/kernel/net/bluetooth/l2cap_core.c:430
 process_one_work+0x793/0x14a0 syzkaller/managers/linux-4-14/kernel/kernel/workqueue.c:2116
 worker_thread+0x5cc/0xff0 syzkaller/managers/linux-4-14/kernel/kernel/workqueue.c:2250
 kthread+0x30d/0x420 syzkaller/managers/linux-4-14/kernel/kernel/kthread.c:232
 ret_from_fork+0x24/0x30 syzkaller/managers/linux-4-14/kernel/arch/x86/entry/entry_64.S:404
Code: 78 01 00 00 4d 8b 36 4c 39 f3 74 78 49 8d 7e 10 4c 89 f0 4c 8b 0d c3 f3 a5 0a 48 89 fa 48 2d 20 0a c7 8b 48 c1 ea 03 48 c1 f8 06 <42> 80 3c 3a 00 0f 85 28 01 00 00 49 8b 4e 10 4c 8d 41 2c 4c 89 
RIP: lock_accessed syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:979 [inline] RSP: ffff8880b560f808
RIP: __bfs.part.0+0x20e/0x470 syzkaller/managers/linux-4-14/kernel/kernel/locking/lockdep.c:1045 RSP: ffff8880b560f808
---[ end trace 464163dd9b9ff7f7 ]---

Crashes (3):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci2-linux-4-14	2021/02/11 21:32	linux-4.14.y	2c8a3fce	a5f86b15	.config	log	report	info	general protection fault in __bfs
ci2-linux-4-14	2020/10/31 00:14	linux-4.14.y	2b791501	18e33098	.config	log	report	info
ci2-linux-4-14	2020/10/19 10:38	linux-4.14.y	cbfa1702	ff4a3345	.config	log	report	info