INFO: task hung in nbd

INFO: task hung in nbd_ioctl (2)
Status: upstream: reported on 2020/07/06 15:22
Reported-by: syzbot+e36f41d207137b5d12f7@syzkaller.appspotmail.com
First crash: 250d, last: 5d21h

similar bugs (4):
Kernel	Title	Repro	Bisected	Count	Last	Reported	Patched	Status
linux-4.14	INFO: task hung in nbd_ioctl	C	fix	18	224d	298d	1/1	fixed on 2019/12/28 10:32
linux-4.14	INFO: task hung in nbd_ioctl (2)	C		13	2d13h	216d	0/1	upstream: reported C repro on 2020/01/03 17:08
upstream	INFO: task hung in nbd_ioctl	C	cause	71	275d	311d	14/17	fixed on 2019/11/06 12:39
linux-4.19	INFO: task hung in nbd_ioctl	C		35	10d	299d	0/1	upstream: reported C repro on 2019/10/12 13:11

Sample crash report:

INFO: task syz-executor.0:20187 blocked for more than 143 seconds.
      Not tainted 5.8.0-rc7-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D28720 20187   6962 0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3458 [inline]
 __schedule+0x8ea/0x2210 kernel/sched/core.c:4219
 schedule+0xd0/0x2a0 kernel/sched/core.c:4294
 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1892
 do_wait_for_common kernel/sched/completion.c:85 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x163/0x260 kernel/sched/completion.c:138
 flush_workqueue+0x3ff/0x13e0 kernel/workqueue.c:2832
 nbd_start_device_ioctl drivers/block/nbd.c:1327 [inline]
 __nbd_ioctl drivers/block/nbd.c:1402 [inline]
 nbd_ioctl+0x7ac/0xb77 drivers/block/nbd.c:1442
 __blkdev_driver_ioctl block/ioctl.c:224 [inline]
 blkdev_ioctl+0x255/0x6c0 block/ioctl.c:620
 block_ioctl+0xf9/0x140 fs/block_dev.c:1988
 vfs_ioctl fs/ioctl.c:48 [inline]
 ksys_ioctl+0x11a/0x180 fs/ioctl.c:753
 __do_sys_ioctl fs/ioctl.c:762 [inline]
 __se_sys_ioctl fs/ioctl.c:760 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cc79
Code: Bad RIP value.
RSP: 002b:00007f5b2e6a6c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000011bc0 RCX: 000000000045cc79
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 000000000078bf38 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c
R13: 00007fffa0ea98af R14: 00007f5b2e6a79c0 R15: 000000000078bf0c

Showing all locks held in the system:
2 locks held by kworker/u4:0/7:
 #0: ffff8880ae635e18 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1261 [inline]
 #0: ffff8880ae635e18 (&rq->lock){-.-.}-{2:2}, at: __schedule+0x22f/0x2210 kernel/sched/core.c:4137
 #1: ffffffff89bc11c0 (rcu_read_lock){....}-{1:2}, at: cpu_of kernel/sched/sched.h:1051 [inline]
 #1: ffffffff89bc11c0 (rcu_read_lock){....}-{1:2}, at: __update_idle_core+0x39/0x3e0 kernel/sched/fair.c:6006
1 lock held by khungtaskd/1154:
 #0: ffffffff89bc11c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5779
2 locks held by kworker/u5:0/1534:
 #0: ffff888092d2d138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888092d2d138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
 #0: ffff888092d2d138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
 #0: ffff888092d2d138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
 #0: ffff888092d2d138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
 #0: ffff888092d2d138 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240
 #1: ffffc900055e7da8 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244
1 lock held by in:imklog/6852:
 #0: ffff88809aff3870 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826

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

NMI backtrace for cpu 1
CPU: 1 PID: 1154 Comm: khungtaskd Not tainted 5.8.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x18f/0x20d lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline]
 watchdog+0xd7d/0x1000 kernel/hung_task.c:295
 kthread+0x3b5/0x4a0 kernel/kthread.c:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 7 Comm: kworker/u4:0 Not tainted 5.8.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x0/0x20 kernel/kcov.c:270
Code: 66 2e 0f 1f 84 00 00 00 00 00 48 8b 0c 24 48 89 f2 48 89 fe bf 06 00 00 00 e9 0c ff ff ff 66 90 66 2e 0f 1f 84 00 00 00 00 00 <48> 8b 0c 24 40 0f b6 d6 40 0f b6 f7 bf 01 00 00 00 e9 ea fe ff ff
RSP: 0018:ffffc90000cdfb90 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff87c8cdf3
RDX: ffff8880a95e41c0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8c5a5a27
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88809ea96094
R13: dffffc0000000000 R14: ffff888093564bc0 R15: 00000000000000e3
FS:  0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6a40200000 CR3: 00000000a75a7000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 rcu_read_unlock include/linux/rcupdate.h:684 [inline]
 batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:771 [inline]
 batadv_iv_ogm_schedule_buff+0x77c/0x1410 net/batman-adv/bat_iv_ogm.c:825
 batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:869 [inline]
 batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:862 [inline]
 batadv_iv_send_outstanding_bat_ogm_packet+0x5c8/0x800 net/batman-adv/bat_iv_ogm.c:1722
 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3b5/0x4a0 kernel/kthread.c:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293

Crashes (36):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Maintainers
ci-upstream-kasan-gce-root	2020/08/01 06:40	upstream	d8b9faec	d895b3be	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-root	2020/07/26 02:05	upstream	23ee3e4e	1f7cc1ca	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-selinux-root	2020/07/17 12:07	upstream	f8456690	54b3c45e	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-root	2020/07/17 12:05	upstream	f8456690	54b3c45e	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-root	2020/07/16 01:23	upstream	e9919e11	f3bec699	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-root	2020/06/25 09:47	upstream	7ae77150	54566aff	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-selinux-root	2020/06/01 19:25	upstream	3d77e6a8	a0331e89	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-root	2020/05/31 17:26	upstream	ffeb595d	a0331e89	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-root	2020/05/26 01:33	upstream	9cb1fd0e	30927cd7	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-selinux-root	2020/05/08 10:47	upstream	6e7f2eac	6c70a1c2	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-selinux-root	2020/05/04 07:25	upstream	262f7a6b	58ae5e18	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-selinux-root	2020/03/29 23:08	upstream	e595dd94	05736b29	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-root	2020/03/28 04:33	upstream	527630fb	831e9a81	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-root	2020/03/10 15:59	upstream	30bb5572	35f53e45	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-smack-root	2020/03/06 12:29	upstream	63623fd4	c88c7b75	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-root	2020/02/29 17:21	upstream	f8788d86	59b57593	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-root	2020/02/29 10:55	upstream	f8788d86	59b57593	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-smack-root	2020/02/28 22:40	upstream	f8788d86	59b57593	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-root	2020/02/25 12:47	upstream	f8788d86	59b57593	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-selinux-root	2020/02/17 21:56	upstream	11a48a5a	2b411596	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-root	2020/02/15 18:24	upstream	2019fc96	5d7b90f1	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-smack-root	2020/02/05 04:33	upstream	33b40134	93e5e335	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-selinux-root	2020/02/02 12:49	upstream	94f2630b	2274ad39	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-selinux-root	2020/01/27 09:16	upstream	a45ea48e	dd56146d	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-smack-root	2020/01/22 15:58	upstream	d96d875e	8eda0b95	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-smack-root	2020/01/19 07:20	upstream	244dc268	bc8bc756	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-root	2019/12/24 18:57	upstream	46cf053e	be5c2c81	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-kasan-gce-smack-root	2019/11/30 17:31	upstream	81b6b964	3a75be00	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-linux-next-kasan-gce-root	2020/07/03 08:37	linux-next	aab20039	bed10395	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-linux-next-kasan-gce-root	2020/06/25 09:41	linux-next	e7b08814	54566aff	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-linux-next-kasan-gce-root	2020/06/25 01:34	linux-next	e7b08814	54566aff	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-linux-next-kasan-gce-root	2020/05/13 05:42	linux-next	ac935d22	a44eb8f7	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-linux-next-kasan-gce-root	2020/03/23 09:25	linux-next	770fbb32	78267cec	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-linux-next-kasan-gce-root	2020/03/04 01:54	linux-next	c99b17ac	c88c7b75	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-linux-next-kasan-gce-root	2020/03/02 16:55	linux-next	c99b17ac	c88c7b75	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org
ci-upstream-linux-next-kasan-gce-root	2019/12/24 18:53	linux-next	7ddd09fc	be5c2c81	.config	log	report	axboe@kernel.dk, josef@toxicpanda.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nbd@other.debian.org