INFO: task hung in nbd

INFO: task hung in nbd_ioctl (3)
Status: upstream: reported C repro on 2020/09/28 07:17
Reported-by: syzbot+fe03c50d25c0188f7487@syzkaller.appspotmail.com
First crash: 387d, last: 39d

Cause bisection: introduced by (bisect log) :
commit e9e006f5fcf2bab59149cb38a48a4817c1b538b4
Author: Mike Christie <mchristi@redhat.com>
Date: Sun Aug 4 19:10:06 2019 +0000

nbd: fix max number of supported devs

Crash: INFO: task hung in nbd_ioctl (log)
Repro: syz .config

Fix bisection: fixed by (bisect log) [merge commit]:
commit da0628559871475b482f015dc24c9bef372936e4
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date: Mon Dec 14 20:05:10 2020 +0000

Merge tag 'tomoyo-pr-20201214' of git://git.osdn.net/gitroot/tomoyo/tomoyo-test1

similar bugs (7):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-4.14	INFO: task hung in nbd_ioctl	C		done	18	663d	737d	1/1	fixed on 2019/12/28 10:32
linux-4.14	INFO: task hung in nbd_ioctl (2)	C		done	16	410d	655d	1/1	fixed on 2020/10/21 11:01
upstream	INFO: task hung in nbd_ioctl (2)				37	417d	470d	17/22	fixed on 2020/09/25 01:17
upstream	INFO: task hung in nbd_ioctl	C	done		71	714d	750d	14/22	fixed on 2019/11/06 12:39
linux-4.19	INFO: task hung in nbd_ioctl	C			56	21d	738d	0/1	upstream: reported C repro on 2019/10/12 13:11
linux-4.14	INFO: task hung in nbd_ioctl (3)	C			7	7d03h	340d	0/1	upstream: reported C repro on 2020/11/13 07:37
upstream	INFO: task can't die in nbd_ioctl	C	done		6	10d	379d	0/22	upstream: reported C repro on 2020/10/05 07:20

Sample crash report:

INFO: task syz-executor408:6566 blocked for more than 143 seconds.
      Not tainted 5.14.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor408 state:D stack:27176 pid: 6566 ppid:  6565 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4940 [inline]
 __schedule+0x940/0x26f0 kernel/sched/core.c:6287
 schedule+0xd3/0x270 kernel/sched/core.c:6366
 schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1857
 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+0x176/0x280 kernel/sched/completion.c:138
 flush_workqueue+0x3ed/0x15b0 kernel/workqueue.c:2869
 nbd_start_device_ioctl drivers/block/nbd.c:1359 [inline]
 __nbd_ioctl drivers/block/nbd.c:1422 [inline]
 nbd_ioctl+0x631/0xa80 drivers/block/nbd.c:1462
 blkdev_ioctl+0x2a1/0x700 block/ioctl.c:589
 block_ioctl+0xf9/0x140 fs/block_dev.c:1421
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl fs/ioctl.c:860 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x444279
RSP: 002b:00007ffea6711e28 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004004a0 RCX: 0000000000444279
RDX: 00000000ffffffff RSI: 000000000000ab03 RDI: 0000000000000005
RBP: 0000000000000000 R08: 00007ffea6711fc8 R09: 00007ffea6711fc8
R10: 00007ffea6711fc8 R11: 0000000000000246 R12: 0000000000403590
R13: 431bde82d7b634db R14: 00000000004b2018 R15: 00000000004004a0

Showing all locks held in the system:
1 lock held by khungtaskd/26:
 #0: ffffffff8b97d360 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446
5 locks held by kworker/u4:2/149:
 #0: ffff8880b9c31ad8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x1e/0x30 kernel/sched/core.c:474
 #1: ffff8880b9c1f9c8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x16a/0x480 kernel/sched/psi.c:871
 #2: ffff8880b9c20258 (&base->lock){..-.}-{2:2}, at: __mod_timer+0x60c/0xe30 kernel/time/timer.c:1043
 #3: ffffffff903f95d8 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x12e/0x3e0 lib/debugobjects.c:661
 #4: ffffffff8b848d88 (text_mutex){+.+.}-{3:3}, at: arch_jump_label_transform_apply+0xe/0x20 arch/x86/kernel/jump_label.c:145
2 locks held by kworker/u5:0/150:
 #0: ffff88806c01e938 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff88806c01e938 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
 #0: ffff88806c01e938 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
 #0: ffff88806c01e938 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:634 [inline]
 #0: ffff88806c01e938 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:661 [inline]
 #0: ffff88806c01e938 ((wq_completion)knbd0-recv){+.+.}-{0:0}, at: process_one_work+0x8a3/0x16b0 kernel/workqueue.c:2268
 #1: ffffc90001707db0 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work+0x8d7/0x16b0 kernel/workqueue.c:2272
1 lock held by in:imklog/6474:

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

NMI backtrace for cpu 1
CPU: 1 PID: 26 Comm: khungtaskd Not tainted 5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xc1d/0xf50 kernel/hung_task.c:295
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 2968 Comm: systemd-journal Not tainted 5.14.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:get_page_owner mm/page_owner.c:98 [inline]
RIP: 0010:__reset_page_owner+0x93/0x170 mm/page_owner.c:143
Code: ae 8b 41 d3 e5 48 c1 e8 03 4c 01 f0 48 89 44 24 08 eb 77 e8 5f d2 b1 ff be 08 00 00 00 48 89 df e8 f2 9a f8 ff 48 0f ba 33 01 <48> 8b 05 36 5e ea 09 48 01 d8 48 8d 78 0c 48 89 fa 48 c1 ea 03 42
RSP: 0018:ffffc90002267c40 EFLAGS: 00000047
RAX: 0000000000000001 RBX: ffff888014319fd0 RCX: ffffffff81c371de
RDX: ffffed10028633fb RSI: 0000000000000008 RDI: ffff888014319fd0
RBP: 0000000000000001 R08: 0000000000000001 R09: ffff888014319fd7
R10: ffffed10028633fa R11: 0000000000086089 R12: 0000000000000001
R13: 0000000000000002 R14: dffffc0000000000 R15: 000000a6d942eacc
FS:  00007f67e33e58c0(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f67e07ca000 CR3: 0000000079091000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1338 [inline]
 free_pcp_prepare+0x2c5/0x780 mm/page_alloc.c:1389
 free_unref_page_prepare mm/page_alloc.c:3315 [inline]
 free_unref_page+0x19/0x690 mm/page_alloc.c:3394
 slab_destroy mm/slab.c:1627 [inline]
 slabs_destroy+0x89/0xc0 mm/slab.c:1647
 cache_flusharray mm/slab.c:3418 [inline]
 ___cache_free+0x4c6/0x610 mm/slab.c:3480
 qlink_free mm/kasan/quarantine.c:146 [inline]
 qlist_free_all+0x4e/0x110 mm/kasan/quarantine.c:165
 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272
 __kasan_slab_alloc+0x92/0xa0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook mm/slab.h:519 [inline]
 slab_alloc mm/slab.c:3323 [inline]
 kmem_cache_alloc+0x25f/0x540 mm/slab.c:3507
 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138
 getname_flags include/linux/audit.h:319 [inline]
 getname fs/namei.c:217 [inline]
 __do_sys_mkdir fs/namei.c:3931 [inline]
 __se_sys_mkdir fs/namei.c:3929 [inline]
 __x64_sys_mkdir+0xda/0x140 fs/namei.c:3929
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f67e26a0687
Code: 00 b8 ff ff ff ff c3 0f 1f 40 00 48 8b 05 09 d8 2b 00 64 c7 00 5f 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 b8 53 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 d7 2b 00 f7 d8 64 89 01 48
RSP: 002b:00007ffd04c1fac8 EFLAGS: 00000293 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007ffd04c229e0 RCX: 00007f67e26a0687
RDX: 00007f67e3111a00 RSI: 00000000000001ed RDI: 00005568137f98c0
RBP: 00007ffd04c1fb00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000069 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ffd04c229e0 R15: 00007ffd04c1fff0
----------------
Code disassembly (best guess):
   0:	ae                   	scas   %es:(%rdi),%al
   1:	8b 41 d3             	mov    -0x2d(%rcx),%eax
   4:	e5 48                	in     $0x48,%eax
   6:	c1 e8 03             	shr    $0x3,%eax
   9:	4c 01 f0             	add    %r14,%rax
   c:	48 89 44 24 08       	mov    %rax,0x8(%rsp)
  11:	eb 77                	jmp    0x8a
  13:	e8 5f d2 b1 ff       	callq  0xffb1d277
  18:	be 08 00 00 00       	mov    $0x8,%esi
  1d:	48 89 df             	mov    %rbx,%rdi
  20:	e8 f2 9a f8 ff       	callq  0xfff89b17
  25:	48 0f ba 33 01       	btrq   $0x1,(%rbx)
* 2a:	48 8b 05 36 5e ea 09 	mov    0x9ea5e36(%rip),%rax        # 0x9ea5e67 <-- trapping instruction
  31:	48 01 d8             	add    %rbx,%rax
  34:	48 8d 78 0c          	lea    0xc(%rax),%rdi
  38:	48 89 fa             	mov    %rdi,%rdx
  3b:	48 c1 ea 03          	shr    $0x3,%rdx
  3f:	42                   	rex.X

Crashes (11):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci-upstream-kasan-gce-selinux-root	2021/09/11 01:33	upstream	bf9f243f23e6	5ae8508a	.config	log	report	syz	C		INFO: task hung in nbd_ioctl
ci-upstream-kasan-gce-root	2021/08/23 04:25	upstream	1bdc3d5be7e1	b599f2fc	.config	log	report	syz	C		INFO: task hung in nbd_ioctl
ci-upstream-kasan-gce-smack-root	2021/08/08 15:31	upstream	85a90500f9a1	6972b106	.config	log	report	syz	C		INFO: task hung in nbd_ioctl
ci-upstream-kasan-gce-root	2021/07/23 11:54	upstream	9bead1b58c4c	bc5f1d88	.config	log	report	syz	C		INFO: task hung in nbd_ioctl
ci-upstream-kasan-gce-smack-root	2021/02/16 06:35	upstream	f40ddce88593	98682e5e	.config	log	report	syz	C		INFO: task hung in nbd_ioctl
ci-upstream-kasan-gce-selinux-root	2020/09/29 09:51	upstream	fb0155a09b02	1b88c6d5	.config	log	report	syz
ci-upstream-kasan-gce-root	2020/09/28 04:35	upstream	a1bffa48745a	5dd8aee8	.config	log	report	syz
ci-upstream-kasan-gce-root	2021/05/05 08:04	upstream	d2b6f8a17919	06c27ff5	.config	log	report			info	INFO: task hung in nbd_ioctl
ci-upstream-kasan-gce-smack-root	2021/04/09 13:26	upstream	4fa56ad0d12e	6a81331a	.config	log	report			info	INFO: task hung in nbd_ioctl
ci-upstream-kasan-gce-selinux-root	2021/02/18 20:23	upstream	f40ddce88593	14052202	.config	log	report			info	INFO: task hung in nbd_ioctl
ci-upstream-kasan-gce-smack-root	2021/02/16 04:14	upstream	f40ddce88593	98682e5e	.config	log	report			info	INFO: task hung in nbd_ioctl