INFO: task can't die in p9_fd

INFO: task can't die in p9_fd_close
Status: upstream: reported C repro on 2020/08/26 10:38
Reported-by: syzbot+fbe34b643e462f65e542@syzkaller.appspotmail.com
First crash: 423d, last: 10d

Cause bisection: introduced by (bisect log) :
commit af3acca3e35c01920fe476f730dca7345d0a48df
Author: Daniel Baluta <daniel.baluta@nxp.com>
Date: Tue Feb 20 12:53:10 2018 +0000

ASoC: ak5558: Fix style for SPDX identifier

Crash: INFO: task hung in p9_fd_close (log)
Repro: C syz .config

similar bugs (3):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	INFO: task hung in p9_fd_close	C	error	error	216	21h51m	781d	0/22	upstream: reported C repro on 2019/08/30 19:28
linux-4.14	INFO: task hung in p9_fd_close	C		inconclusive	53	156d	800d	0/1	upstream: reported C repro on 2019/08/11 15:06
linux-4.19	INFO: task hung in p9_fd_close	C			70	18d	792d	0/1	upstream: reported C repro on 2019/08/19 15:52

Sample crash report:

INFO: task syz-executor137:7905 can't die for more than 143 seconds.
task:syz-executor137 state:D stack:27968 pid: 7905 ppid:  6606 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4698 [inline]
 __schedule+0x949/0x2710 kernel/sched/core.c:5955
 schedule+0xd3/0x290 kernel/sched/core.c:6034
 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_work+0x50e/0xad0 kernel/workqueue.c:3053
 __cancel_work_timer+0x3f9/0x570 kernel/workqueue.c:3140
 p9_conn_destroy net/9p/trans_fd.c:886 [inline]
 p9_fd_close+0x29c/0x520 net/9p/trans_fd.c:921
 p9_client_destroy+0xbe/0x370 net/9p/client.c:1088
 v9fs_session_close+0x45/0x2c0 fs/9p/v9fs.c:498
 v9fs_kill_super+0x49/0x90 fs/9p/vfs_super.c:224
 deactivate_locked_super+0x94/0x160 fs/super.c:335
 v9fs_mount+0x7d0/0x9c0 fs/9p/vfs_super.c:205
 legacy_get_tree+0x105/0x220 fs/fs_context.c:610
 vfs_get_tree+0x89/0x2f0 fs/super.c:1498
 do_new_mount fs/namespace.c:2978 [inline]
 path_mount+0x132a/0x1fa0 fs/namespace.c:3308
 do_mount fs/namespace.c:3321 [inline]
 __do_sys_mount fs/namespace.c:3529 [inline]
 __se_sys_mount fs/namespace.c:3506 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3506
 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: 0033:0x445c19
RSP: 002b:00007f8953c232f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00000000004cb4e0 RCX: 0000000000445c19
RDX: 0000000020000140 RSI: 00000000200002c0 RDI: 0000000000000000
RBP: 000000000049b07c R08: 0000000020000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e
R13: 613d737365636361 R14: 64663d736e617274 R15: 00000000004cb4e8
INFO: task syz-executor137:7905 blocked for more than 143 seconds.
      Not tainted 5.14.0-rc5-next-20210809-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor137 state:D stack:27968 pid: 7905 ppid:  6606 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4698 [inline]
 __schedule+0x949/0x2710 kernel/sched/core.c:5955
 schedule+0xd3/0x290 kernel/sched/core.c:6034
 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_work+0x50e/0xad0 kernel/workqueue.c:3053
 __cancel_work_timer+0x3f9/0x570 kernel/workqueue.c:3140
 p9_conn_destroy net/9p/trans_fd.c:886 [inline]
 p9_fd_close+0x29c/0x520 net/9p/trans_fd.c:921
 p9_client_destroy+0xbe/0x370 net/9p/client.c:1088
 v9fs_session_close+0x45/0x2c0 fs/9p/v9fs.c:498
 v9fs_kill_super+0x49/0x90 fs/9p/vfs_super.c:224
 deactivate_locked_super+0x94/0x160 fs/super.c:335
 v9fs_mount+0x7d0/0x9c0 fs/9p/vfs_super.c:205
 legacy_get_tree+0x105/0x220 fs/fs_context.c:610
 vfs_get_tree+0x89/0x2f0 fs/super.c:1498
 do_new_mount fs/namespace.c:2978 [inline]
 path_mount+0x132a/0x1fa0 fs/namespace.c:3308
 do_mount fs/namespace.c:3321 [inline]
 __do_sys_mount fs/namespace.c:3529 [inline]
 __se_sys_mount fs/namespace.c:3506 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3506
 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: 0033:0x445c19
RSP: 002b:00007f8953c232f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00000000004cb4e0 RCX: 0000000000445c19
RDX: 0000000020000140 RSI: 00000000200002c0 RDI: 0000000000000000
RBP: 000000000049b07c R08: 0000000020000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e
R13: 613d737365636361 R14: 64663d736e617274 R15: 00000000004cb4e8

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8b97e940 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446
2 locks held by kworker/0:2/1280:
 #0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
 #0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
 #0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline]
 #0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x871/0x1630 kernel/workqueue.c:2247
 #1: ffffc90005437db0 ((work_completion)(&m->rq)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1630 kernel/workqueue.c:2251
2 locks held by systemd-udevd/2985:
 #0: ffff8880b9c31a18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:460 [inline]
 #0: ffff8880b9c31a18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1309 [inline]
 #0: ffff8880b9c31a18 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1612 [inline]
 #0: ffff8880b9c31a18 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x233/0x2710 kernel/sched/core.c:5869
 #1: ffff8880b9c1f988 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39d/0x480 kernel/sched/psi.c:880
1 lock held by in:imklog/6288:
2 locks held by kworker/1:3/6293:
 #0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
 #0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
 #0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline]
 #0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x871/0x1630 kernel/workqueue.c:2247
 #1: ffffc9000c7d7db0 ((work_completion)(&m->rq)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1630 kernel/workqueue.c:2251
1 lock held by syz-executor137/26095:
 #0: ffffffff8ba820a8 (slab_mutex){+.+.}-{3:3}, at: kmem_cache_destroy+0x1e/0x120 mm/slab_common.c:505
1 lock held by syz-executor137/26109:
 #0: ffffffff8ba820a8 (slab_mutex){+.+.}-{3:3}, at: kmem_cache_destroy+0x1e/0x120 mm/slab_common.c:505
1 lock held by syz-executor137/26103:
1 lock held by syz-executor137/26113:
 #0: ffffffff8ba820a8 (slab_mutex){+.+.}-{3:3}, at: kmem_cache_destroy+0x1e/0x120 mm/slab_common.c:505
1 lock held by syz-executor137/26135:
 #0: ffffffff8ba820a8 (slab_mutex){+.+.}-{3:3}, at: kmem_cache_create_usercopy+0x38/0x2e0 mm/slab_common.c:330
1 lock held by syz-executor137/26137:
 #0: ffffffff8ba820a8 (slab_mutex){+.+.}-{3:3}, at: kmem_cache_create_usercopy+0x38/0x2e0 mm/slab_common.c:330

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.14.0-rc5-next-20210809-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:105
 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:254 [inline]
 watchdog+0xcb7/0xed0 kernel/hung_task.c:339
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 2972 Comm: systemd-journal Not tainted 5.14.0-rc5-next-20210809-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__raw_spin_lock_irq include/linux/spinlock_api_smp.h:126 [inline]
RIP: 0010:_raw_spin_lock_irq+0x3c/0x50 kernel/locking/spinlock.c:167
Code: 6a 9e 1e f8 45 31 c9 41 b8 01 00 00 00 31 c9 ff 74 24 08 48 8d 7d 18 31 d2 31 f6 e8 7e 42 2a f8 48 89 ef 58 5d e9 d4 ac 2a f8 <e8> 2f ed 4a f8 eb c9 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 41 54
RSP: 0018:ffffc90002aefeb8 EFLAGS: 00000002
RAX: 0000000000000293 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: ffff88807bfbd580 RSI: ffffffff814cd235 RDI: ffff88807bfbde98
RBP: ffff88807bfbde98 R08: 0000000000000001 R09: ffff88807bfbde07
R10: ffffed100f7f7bc0 R11: 0000000000000000 R12: ffff88807bfbde98
R13: ffff88807bfbd580 R14: 0000000000000000 R15: ffff88806ef15900
FS:  00007f6a591608c0(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6a569fe000 CR3: 0000000018fab000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 task_work_run+0xb4/0x1a0 kernel/task_work.c:159
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
 exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:209
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f6a586ef840
Code: 73 01 c3 48 8b 0d 68 77 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 89 bb 20 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e f6 ff ff 48 89 04 24
RSP: 002b:00007ffdb12ccec8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: fffffffffffffffe RBX: 00007ffdb12cd1d0 RCX: 00007f6a586ef840
RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 000055f1f33815c0
RBP: 000000000000000d R08: 00000000000001e0 R09: 00000000ffffffff
R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000055f1f3374040 R14: 00007ffdb12cd190 R15: 000055f1f3381610

Crashes (41):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci-upstream-linux-next-kasan-gce-root	2021/08/10 07:47	linux-next	da454ebf578f	6972b106	.config	log	report	syz	C		INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2020/08/22 10:34	linux-next	494d311a82bb	6436ce4b	.config	log	report	syz	C
ci-upstream-linux-next-kasan-gce-root	2021/08/01 15:45	linux-next	8d4b477da1a8	6c236867	.config	log	report	syz			INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/06/21 19:58	linux-next	a1f92694393a	aba2b2fb	.config	log	report	syz			INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/06/21 10:11	linux-next	a1f92694393a	aba2b2fb	.config	log	report	syz			INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/06/14 05:15	linux-next	a1f92694393a	1ba81399	.config	log	report	syz			INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/10/09 12:49	linux-next	683f29b781ae	838e7e2c	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/10/08 03:54	linux-next	f8dc23b3dc0c	efe0f24d	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/10/06 19:51	linux-next	0dda5ee37364	62ee0987	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/10/05 15:24	linux-next	29616f67fcbd	0a63fd36	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/09/25 16:28	linux-next	5a5d008887b4	8cac236e	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/09/15 06:54	linux-next	70ced02f322f	07e953c1	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/09/10 15:43	linux-next	aa14a3016182	5ae8508a	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/08/28 18:41	linux-next	5e63226c7228	be2c130d	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/08/20 15:16	linux-next	86ed57fd8c93	b599f2fc	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/08/09 19:15	linux-next	da454ebf578f	6972b106	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/08/04 03:27	linux-next	8d4b477da1a8	6c236867	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/07/30 13:58	linux-next	4ccc9e2db7ac	c585c7b0	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/07/09 05:17	linux-next	e2f74b13dbe6	1b20171a	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/06/19 20:17	linux-next	a1f92694393a	aba2b2fb	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/05/20 16:04	linux-next	a1f92694393a	c560a65d	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/05/18 16:08	linux-next	a1f92694393a	a343ba6b	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/05/11 14:47	linux-next	4bf27b1f7330	ca873091	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/04/21 04:47	linux-next	1216f02e46a4	c0ced557	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/04/13 16:02	linux-next	dcf1b51d6b2a	bfeda1b1	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/04/13 08:42	linux-next	5df924d19629	bfeda1b1	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/04/03 10:22	linux-next	454c576c3f5e	6a81331a	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/04/01 17:53	linux-next	454c576c3f5e	6a81331a	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/03/22 15:32	linux-next	e3128d2f068e	bea32f74	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/02/24 16:30	linux-next	577c283560fe	fcc6d71b	.config	log	report			info	INFO: task can't die in p9_fd_close
ci-upstream-linux-next-kasan-gce-root	2021/01/14 01:52	linux-next	aa515cdce7a1	269d24e8	.config	log	report			info
ci-upstream-linux-next-kasan-gce-root	2021/01/13 14:10	linux-next	aa515cdce7a1	a945f0a3	.config	log	report			info
ci-upstream-linux-next-kasan-gce-root	2021/01/12 23:15	linux-next	df869cab4b35	0cdd6185	.config	log	report			info
ci-upstream-linux-next-kasan-gce-root	2021/01/11 04:12	linux-next	1c925d2030af	2c1f2513	.config	log	report			info
ci-upstream-linux-next-kasan-gce-root	2021/01/03 06:42	linux-next	d7a03a44a5e9	79264ae3	.config	log	report			info
ci-upstream-linux-next-kasan-gce-root	2021/01/02 16:16	linux-next	d7a03a44a5e9	79264ae3	.config	log	report			info
ci-upstream-linux-next-kasan-gce-root	2020/12/13 18:01	linux-next	14240d4c5b25	bca53db9	.config	log	report			info
ci-upstream-linux-next-kasan-gce-root	2020/12/08 12:06	linux-next	15ac8fdb7440	51a9082e	.config	log	report			info
ci-upstream-linux-next-kasan-gce-root	2020/12/06 14:44	linux-next	0eedceafd3a6	f12ba0c5	.config	log	report			info
ci-upstream-linux-next-kasan-gce-root	2020/11/29 20:10	linux-next	6174f05255e6	a0092f9d	.config	log	report			info
ci-upstream-linux-next-kasan-gce-root	2020/11/22 08:18	linux-next	95065cb54210	0d27f508	.config	log	report			info