INFO: task can't die in io_uring

INFO: task can't die in io_uring_setup
Status: upstream: reported syz repro on 2020/09/03 16:28
Reported-by: syzbot+3227d097b95b4207b570@syzkaller.appspotmail.com
First crash: 290d, last: 284d

Cause bisection: introduced by (bisect log) :
commit dfe127799f8e663c7e3e48b5275ca538b278177b
Author: Stefano Garzarella <sgarzare@redhat.com>
Date: Thu Aug 27 14:58:31 2020 +0000

io_uring: allow disabling rings during the creation

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

Sample crash report:

INFO: task syz-executor.2:8274 can't die for more than 143 seconds.
task:syz-executor.2  state:D stack:29752 pid: 8274 ppid:  6909 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3777 [inline]
 __schedule+0xea9/0x2230 kernel/sched/core.c:4526
 schedule+0xd0/0x2a0 kernel/sched/core.c:4601
 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1855
 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
 io_sq_thread_stop fs/io_uring.c:6906 [inline]
 io_finish_async fs/io_uring.c:6920 [inline]
 io_sq_offload_create fs/io_uring.c:7595 [inline]
 io_uring_create fs/io_uring.c:8671 [inline]
 io_uring_setup+0x1495/0x29a0 fs/io_uring.c:8744
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d5b9
Code: Bad RIP value.
RSP: 002b:00007fdaaa465c78 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9
RAX: ffffffffffffffda RBX: 0000000000008540 RCX: 000000000045d5b9
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000003f39
RBP: 000000000118d018 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cfec
R13: 00007ffe313b353f R14: 00007fdaaa4669c0 R15: 000000000118cfec
INFO: task syz-executor.2:8274 blocked for more than 143 seconds.
      Not tainted 5.9.0-rc3-next-20200903-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2  state:D stack:29752 pid: 8274 ppid:  6909 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3777 [inline]
 __schedule+0xea9/0x2230 kernel/sched/core.c:4526
 schedule+0xd0/0x2a0 kernel/sched/core.c:4601
 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1855
 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
 io_sq_thread_stop fs/io_uring.c:6906 [inline]
 io_finish_async fs/io_uring.c:6920 [inline]
 io_sq_offload_create fs/io_uring.c:7595 [inline]
 io_uring_create fs/io_uring.c:8671 [inline]
 io_uring_setup+0x1495/0x29a0 fs/io_uring.c:8744
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d5b9
Code: Bad RIP value.
RSP: 002b:00007fdaaa465c78 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9
RAX: ffffffffffffffda RBX: 0000000000008540 RCX: 000000000045d5b9
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000003f39
RBP: 000000000118d018 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cfec
R13: 00007ffe313b353f R14: 00007fdaaa4669c0 R15: 000000000118cfec
INFO: task io_uring-sq:8275 blocked for more than 143 seconds.
      Not tainted 5.9.0-rc3-next-20200903-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:io_uring-sq     state:D stack:31120 pid: 8275 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:3777 [inline]
 __schedule+0xea9/0x2230 kernel/sched/core.c:4526
 schedule+0xd0/0x2a0 kernel/sched/core.c:4601
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4660
 kthread+0x2ac/0x4a0 kernel/kthread.c:285
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
INFO: task syz-executor.3:8359 can't die for more than 144 seconds.
task:syz-executor.3  state:D stack:28992 pid: 8359 ppid:  6906 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3777 [inline]
 __schedule+0xea9/0x2230 kernel/sched/core.c:4526
 schedule+0xd0/0x2a0 kernel/sched/core.c:4601
 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1855
 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
 io_sq_thread_stop fs/io_uring.c:6906 [inline]
 io_finish_async fs/io_uring.c:6920 [inline]
 io_sq_offload_create fs/io_uring.c:7595 [inline]
 io_uring_create fs/io_uring.c:8671 [inline]
 io_uring_setup+0x1495/0x29a0 fs/io_uring.c:8744
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d5b9
Code: Bad RIP value.
RSP: 002b:00007f1f142fcc78 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9
RAX: ffffffffffffffda RBX: 0000000000008540 RCX: 000000000045d5b9
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000003f39
RBP: 000000000118d018 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cfec
R13: 00007ffe1ddc7acf R14: 00007f1f142fd9c0 R15: 000000000118cfec
INFO: task syz-executor.3:8359 blocked for more than 144 seconds.
      Not tainted 5.9.0-rc3-next-20200903-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:28992 pid: 8359 ppid:  6906 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:3777 [inline]
 __schedule+0xea9/0x2230 kernel/sched/core.c:4526
 schedule+0xd0/0x2a0 kernel/sched/core.c:4601
 schedule_timeout+0x1d8/0x250 kernel/time/timer.c:1855
 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
 io_sq_thread_stop fs/io_uring.c:6906 [inline]
 io_finish_async fs/io_uring.c:6920 [inline]
 io_sq_offload_create fs/io_uring.c:7595 [inline]
 io_uring_create fs/io_uring.c:8671 [inline]
 io_uring_setup+0x1495/0x29a0 fs/io_uring.c:8744
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d5b9
Code: Bad RIP value.
RSP: 002b:00007f1f142fcc78 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9
RAX: ffffffffffffffda RBX: 0000000000008540 RCX: 000000000045d5b9
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000003f39
RBP: 000000000118d018 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cfec
R13: 00007ffe1ddc7acf R14: 00007f1f142fd9c0 R15: 000000000118cfec
INFO: task io_uring-sq:8361 blocked for more than 144 seconds.
      Not tainted 5.9.0-rc3-next-20200903-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:io_uring-sq     state:D stack:31120 pid: 8361 ppid:     2 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:3777 [inline]
 __schedule+0xea9/0x2230 kernel/sched/core.c:4526
 schedule+0xd0/0x2a0 kernel/sched/core.c:4601
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4660
 kthread+0x2ac/0x4a0 kernel/kthread.c:285
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Showing all locks held in the system:
1 lock held by khungtaskd/1170:
 #0: ffffffff89c67500 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5829
1 lock held by in:imklog/6573:
 #0: ffff888096d8f130 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930

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

NMI backtrace for cpu 1
CPU: 1 PID: 1170 Comm: khungtaskd Not tainted 5.9.0-rc3-next-20200903-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+0x198/0x1fd lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline]
 watchdog+0xd89/0xf30 kernel/hung_task.c:339
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3891 Comm: systemd-journal Not tainted 5.9.0-rc3-next-20200903-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:398 [inline]
RIP: 0010:lock_release+0x41d/0x8f0 kernel/locking/lockdep.c:5028
Code: 84 c0 74 0c 3c 03 7f 08 4c 89 cf e8 ad e2 5a 00 2b 5c 24 40 41 39 9f 08 09 00 00 0f 85 9a 02 00 00 65 4c 8b 24 25 c0 fe 01 00 <49> 8d bc 24 0c 09 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48
RSP: 0018:ffffc900050c77e8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 1ffff11012923d48 RSI: ffffffff89c67500 RDI: ffff88809491ea40
RBP: 1ffff92000a18eff R08: 0000000000000001 R09: ffff88809491ea48
R10: fffffbfff15796c1 R11: 0000000000000000 R12: ffff88809491e140
R13: 0000000000000000 R14: ffffffff8180b769 R15: ffff88809491e140
FS:  00007ff99f6f28c0(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff99cad7000 CR3: 0000000094a25000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 rcu_lock_release include/linux/rcupdate.h:253 [inline]
 rcu_read_unlock include/linux/rcupdate.h:695 [inline]
 is_bpf_text_address+0xcb/0x160 kernel/bpf/core.c:706
 kernel_text_address kernel/extable.c:151 [inline]
 kernel_text_address+0xbd/0xf0 kernel/extable.c:120
 __kernel_text_address+0x9/0x30 kernel/extable.c:105
 unwind_get_return_address arch/x86/kernel/unwind_orc.c:317 [inline]
 unwind_get_return_address+0x51/0x90 arch/x86/kernel/unwind_orc.c:312
 arch_stack_walk+0x97/0xf0 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:123
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56
 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355
 __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422
 __cache_free mm/slab.c:3418 [inline]
 kmem_cache_free.part.0+0x74/0x1e0 mm/slab.c:3693
 putname+0xe1/0x120 fs/namei.c:259
 filename_lookup+0x3b1/0x560 fs/namei.c:2376
 user_path_at include/linux/namei.h:59 [inline]
 do_faccessat+0x129/0x820 fs/open.c:423
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7ff99e9ae9c7
Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48
RSP: 002b:00007ffff3b1fdb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000015
RAX: ffffffffffffffda RBX: 00007ffff3b22cd0 RCX: 00007ff99e9ae9c7
RDX: 00007ff99f41fa00 RSI: 0000000000000000 RDI: 0000562a5a9c69a3
RBP: 00007ffff3b1fdf0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ffff3b22cd0 R15: 00007ffff3b202e0

Crashes (455):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro
ci-upstream-linux-next-kasan-gce-root	2020/09/05 17:21	linux-next	7a695657	abf9ba4f	.config	log	report	syz
ci-upstream-linux-next-kasan-gce-root	2020/09/04 20:22	linux-next	7a695657	abf9ba4f	.config	log	report	syz
ci-upstream-linux-next-kasan-gce-root	2020/09/04 14:05	linux-next	7a695657	abf9ba4f	.config	log	report	syz
ci-upstream-linux-next-kasan-gce-root	2020/09/04 03:30	linux-next	7a695657	abf9ba4f	.config	log	report	syz
ci-upstream-linux-next-kasan-gce-root	2020/09/04 00:20	linux-next	7a695657	abf9ba4f	.config	log	report	syz
ci-upstream-linux-next-kasan-gce-root	2020/09/03 18:45	linux-next	7a695657	abf9ba4f	.config	log	report	syz
ci-upstream-linux-next-kasan-gce-root	2020/09/03 15:45	linux-next	7a695657	abf9ba4f	.config	log	report	syz
ci-upstream-linux-next-kasan-gce-root	2020/09/02 22:31	linux-next	4442749a	abf9ba4f	.config	log	report	syz
ci-upstream-linux-next-kasan-gce-root	2020/09/08 16:24	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/08 14:55	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/08 14:40	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/08 11:54	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/08 11:32	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/08 10:31	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/08 10:18	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/08 09:17	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/08 09:16	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/08 08:13	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/08 07:26	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/08 07:13	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/08 05:21	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/08 04:11	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/08 03:03	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/08 01:56	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/08 01:52	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/08 00:39	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/07 23:38	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/07 22:27	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/07 21:23	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/07 20:57	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/07 19:30	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/07 18:29	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/07 18:14	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/07 17:07	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/07 10:01	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/07 07:03	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/07 05:56	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/07 05:03	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/07 03:59	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/07 02:38	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/07 00:53	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/07 00:46	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/06 21:37	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/06 19:56	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/06 18:55	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/06 17:24	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/06 15:55	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/06 15:47	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/06 14:33	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/06 12:57	linux-next	7a695657	abf9ba4f	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2020/09/02 13:23	linux-next	4442749a	abf9ba4f	.config	log	report