WARNING in hci_conn

WARNING in hci_conn_timeout
Status: upstream: reported C repro on 2020/08/01 18:55
Reported-by: syzbot+2446dd3cb07277388db6@syzkaller.appspotmail.com
First crash: 262d, last: 12d

Cause bisection: introduced by (bisect log) :
commit 3d30311c0e4d834c94e6a27d6242a942d6a76b85
Author: Varsha Rao <rvarsha016@gmail.com>
Date: Sun Oct 9 11:13:56 2016 +0000

staging: vt6655: Removes unnecessary blank lines.

Crash: WARNING in nf_unregister_net_hook (log)
Repro: C syz .config

similar bugs (2):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-4.14	WARNING in hci_conn_timeout	C			18	21d	264d	0/1	upstream: reported C repro on 2020/07/31 02:13
linux-4.19	WARNING in hci_conn_timeout	C			11	28d	262d	0/1	upstream: reported C repro on 2020/08/01 17:09

Sample crash report:

------------[ cut here ]------------
WARNING: CPU: 1 PID: 1542 at net/bluetooth/hci_conn.c:412 hci_conn_timeout+0x248/0x2a0 net/bluetooth/hci_conn.c:412
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 1542 Comm: kworker/u5:0 Not tainted 5.9.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: hci0 hci_conn_timeout
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x198/0x1fd lib/dump_stack.c:118
 panic+0x347/0x7c0 kernel/panic.c:231
 __warn.cold+0x20/0x46 kernel/panic.c:600
 report_bug+0x1bd/0x210 lib/bug.c:198
 handle_bug+0x38/0x90 arch/x86/kernel/traps.c:234
 exc_invalid_op+0x14/0x40 arch/x86/kernel/traps.c:254
 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536
RIP: 0010:hci_conn_timeout+0x248/0x2a0 net/bluetooth/hci_conn.c:412
Code: 93 a0 02 00 00 48 c1 e8 03 80 3c 08 00 75 50 48 8b 35 9c 38 8e 03 bf 40 00 00 00 e8 82 f3 27 fa e9 21 ff ff ff e8 b8 19 50 fa <0f> 0b e9 2c fe ff ff 48 89 ef e8 99 1f 90 fa e9 f2 fd ff ff e8 6f
RSP: 0018:ffffc900056b7ce8 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff88809b664130 RCX: ffffffff872431dd
RDX: ffff8880a405a1c0 RSI: ffffffff872433c8 RDI: 0000000000000005
RBP: 00000000ffff6ba3 R08: 0000000000000000 R09: ffff88809b664013
R10: 0000000000000000 R11: 1ffffffff18367c0 R12: 0000000000000001
R13: ffff88809b664140 R14: ffff8880a62c2f00 R15: ffff8880a447f800
 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Kernel Offset: disabled
Rebooting in 86400 seconds..

Fix bisection attempts:
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro
ci-upstream-kasan-gce-selinux-root	2021/04/08 09:57	upstream	454859c5	79fb24e2	.config	log	report	syz	C
ci-upstream-kasan-gce-selinux-root	2021/03/03 17:31	upstream	f69d02e3	79fb24e2	.config	log	report	syz	C
ci-upstream-kasan-gce-selinux-root	2021/01/25 22:58	upstream	f8ad8187	79fb24e2	.config	log	report	syz	C

Crashes (31):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci-upstream-kasan-gce-selinux-root	2020/09/12 06:32	upstream	e8878ab8	79fb24e2	.config	log	report	syz	C
ci-upstream-kasan-gce-root	2020/09/11 04:54	upstream	7fe10096	409809d8	.config	log	report	syz	C
ci-upstream-kasan-gce-smack-root	2020/09/07 06:25	upstream	a8205e31	abf9ba4f	.config	log	report	syz	C
ci-upstream-kasan-gce	2020/09/06 17:53	upstream	dd9fb9bb	abf9ba4f	.config	log	report	syz	C
ci-upstream-kasan-gce	2020/08/14 03:03	upstream	990f2273	54ce1ed6	.config	log	report	syz	C
ci-upstream-kasan-gce-smack-root	2020/08/01 16:24	upstream	7dc6fd0f	d895b3be	.config	log	report	syz	C
ci-upstream-kasan-gce-386	2020/09/06 21:42	upstream	dd9fb9bb	abf9ba4f	.config	log	report	syz	C
ci-upstream-linux-next-kasan-gce-root	2020/09/24 21:57	linux-next	d1d2220c	54289b08	.config	log	report	syz	C
ci-upstream-linux-next-kasan-gce-root	2020/08/05 18:50	linux-next	01830e6c	b7129355	.config	log	report	syz	C
ci-qemu2-arm64-mte	2021/03/08 16:56	upstream	144c79ef	09fbf400	.config	log	report			info	WARNING in hci_conn_timeout
ci-upstream-kasan-gce	2020/12/26 22:20	upstream	40f78232	821e0b09	.config	log	report			info
ci-upstream-kasan-gce	2020/12/15 18:56	upstream	148842c9	97183ed7	.config	log	report			info
ci-upstream-kasan-gce-smack-root	2020/11/28 08:15	upstream	99c710c4	486f93ef	.config	log	report			info
ci-upstream-kasan-gce	2020/11/06 17:07	upstream	521b619a	64069d48	.config	log	report			info
ci-upstream-kasan-gce	2020/10/10 10:07	upstream	6f2f486d	93817d89	.config	log	report			info
ci-upstream-kasan-gce-root	2020/09/29 10:01	upstream	fb0155a0	1b88c6d5	.config	log	report			info
ci-upstream-kasan-gce-root	2020/09/24 13:49	upstream	c9c9e6a4	54289b08	.config	log	report			info
ci-upstream-kasan-gce-root	2020/09/24 12:03	upstream	c9c9e6a4	54289b08	.config	log	report			info
ci-upstream-kasan-gce	2020/08/31 14:24	upstream	dcc5c6f0	d5a3ae1f	.config	log	report
ci-upstream-kasan-gce-smack-root	2020/08/21 18:00	upstream	da2968ff	6436ce4b	.config	log	report
ci-upstream-kasan-gce-root	2020/08/13 05:29	upstream	fb893de3	bc15f7db	.config	log	report
ci-upstream-kasan-gce-selinux-root	2020/08/08 05:35	upstream	5631c5e0	ff51e522	.config	log	report
ci-upstream-kasan-gce-root	2020/08/08 05:28	upstream	5631c5e0	ff51e522	.config	log	report
ci-upstream-kasan-gce-root	2020/08/06 06:14	upstream	fffe3ae0	0487ea6f	.config	log	report
ci-upstream-kasan-gce-selinux-root	2020/08/02 10:47	upstream	ac3a0c84	63a73341	.config	log	report
ci-upstream-kasan-gce-selinux-root	2020/08/02 10:42	upstream	ac3a0c84	63a73341	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/11/11 23:05	linux-next	6dd65e60	cca87986	.config	log	report			info
ci-upstream-linux-next-kasan-gce-root	2020/08/08 05:26	linux-next	01830e6c	ff51e522	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/08/05 19:13	linux-next	01830e6c	b7129355	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/08/02 12:18	linux-next	01830e6c	63a73341	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/08/02 12:17	linux-next	01830e6c	63a73341	.config	log	report