INFO: task syz-executor555:6843 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-executor555 state:D stack:28104 pid: 6843 ppid:  6837 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_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: 0033:0x440299
Code: Bad RIP value.
RSP: 002b:00007ffc6f8f1bc8 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440299
RDX: 0000000000400b40 RSI: 0000000020000000 RDI: 000000000000497a
RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000401aa0
R13: 0000000000401b30 R14: 0000000000000000 R15: 0000000000000000
INFO: task io_uring-sq:6844 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:31200 pid: 6844 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/1149:
 #0: ffffffff89c67500 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5829
no locks held by systemd-journal/3899.
1 lock held by in:imklog/6534:

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

NMI backtrace for cpu 1
CPU: 1 PID: 1149 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: 3899 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_is_held_type+0xb1/0xf0 kernel/locking/lockdep.c:5046
Code: b6 46 22 45 31 e4 83 e0 03 39 c8 41 0f 94 c4 65 48 8b 14 25 c0 fe 01 00 8b 82 0c 09 00 00 83 e8 01 66 85 c0 89 82 0c 09 00 00 <75> 27 4c 89 ff e8 95 f4 5f f9 48 83 c4 08 44 89 e0 5b 5d 41 5c 41
RSP: 0018:ffffc900052dfaa0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000002 RCX: 1ffffffff130b120
RDX: ffff888093d92340 RSI: ffffffff89c67440 RDI: ffff888093d92c78
RBP: ffff888093d92340 R08: 0000000000000000 R09: ffffffff8abcb60f
R10: fffffbfff15796c1 R11: 0000000000000000 R12: 0000000000000000
R13: ffff888093d92c50 R14: ffff888093d92c78 R15: 0000000000000086
FS:  00007fe7f74b18c0(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe7f4857000 CR3: 0000000093dc8000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 lock_is_held include/linux/lockdep.h:267 [inline]
 rcu_read_lock_sched_held+0x3a/0xb0 kernel/rcu/update.c:123
 trace_lock_release include/trace/events/lock.h:58 [inline]
 lock_release+0x6a1/0x8f0 kernel/locking/lockdep.c:5017
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:158 [inline]
 _raw_spin_unlock_irqrestore+0x16/0x90 kernel/locking/spinlock.c:191
 __debug_check_no_obj_freed lib/debugobjects.c:977 [inline]
 debug_check_no_obj_freed+0x20c/0x41c lib/debugobjects.c:998
 free_pages_prepare mm/page_alloc.c:1214 [inline]
 __free_pages_ok+0x240/0xd20 mm/page_alloc.c:1471
 slab_destroy mm/slab.c:1625 [inline]
 slabs_destroy+0x89/0xc0 mm/slab.c:1641
 cache_flusharray mm/slab.c:3405 [inline]
 ___cache_free+0x4fb/0x740 mm/slab.c:3455
 qlink_free mm/kasan/quarantine.c:149 [inline]
 qlist_free_all+0x98/0x170 mm/kasan/quarantine.c:168
 quarantine_reduce+0x17e/0x200 mm/kasan/quarantine.c:261
 __kasan_kmalloc.constprop.0+0x9e/0xd0 mm/kasan/common.c:442
 slab_post_alloc_hook mm/slab.h:517 [inline]
 slab_alloc mm/slab.c:3312 [inline]
 kmem_cache_alloc+0x13a/0x3a0 mm/slab.c:3482
 prepare_creds+0x3b/0x730 kernel/cred.c:258
 access_override_creds fs/open.c:353 [inline]
 do_faccessat+0x3d7/0x820 fs/open.c:417
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fe7f676d9c7
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:00007ffef9b5d598 EFLAGS: 00000246 ORIG_RAX: 0000000000000015
RAX: ffffffffffffffda RBX: 00007ffef9b605c0 RCX: 00007fe7f676d9c7
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00005582d4e3e9a3
RBP: 00007ffef9b5d6e0 R08: 00005582d4e343e5 R09: 0000000000000018
R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00005582d63bc8a0 R15: 00007ffef9b5dbd0