INFO: task syz-executor010:6848 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-executor010 state:D stack:28104 pid: 6848 ppid: 6842 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:00007ffdf857da68 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440299 RDX: 0000000000400b40 RSI: 0000000020000180 RDI: 0000000000002c43 RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000401aa0 R13: 0000000000401b30 R14: 0000000000000000 R15: 0000000000000000 INFO: task io_uring-sq:6849 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: 6849 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/1168: #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/6545: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1168 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3897 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:__kasan_check_read+0x0/0x10 mm/kasan/common.c:71 Code: 6d 89 e8 b7 fc 08 00 48 8b 73 58 89 c2 48 c7 c7 f0 0c 6d 89 f7 da e8 27 83 a8 ff e9 a1 f5 ff ff cc cc cc cc cc cc cc cc cc cc <48> 8b 0c 24 89 f6 31 d2 e9 e3 2a 00 00 0f 1f 00 48 8b 0c 24 89 f6 RSP: 0018:ffffc9000519fc50 EFLAGS: 00000046 RAX: 1ffffd400049be09 RBX: ffffea00024df048 RCX: ffffffff81ac3d59 RDX: fffff9400049be0b RSI: 0000000000000004 RDI: ffffea00024df070 RBP: ffffea00024df070 R08: 0000000000000000 R09: ffffea00024df057 R10: fffff9400049be0a R11: 0000000000000000 R12: 0000000000000001 R13: dffffc0000000000 R14: ffffea00024df040 R15: ffffea00024df000 FS: 00007f0f87bc98c0(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0f84f6e020 CR3: 0000000093fde000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:71 [inline] atomic_read include/asm-generic/atomic-instrumented.h:27 [inline] page_expected_state mm/page_alloc.c:1053 [inline] check_free_page mm/page_alloc.c:1098 [inline] free_pages_prepare mm/page_alloc.c:1191 [inline] __free_pages_ok+0x63b/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: 0033:0x7f0f86e859c7 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:00007ffc2857e718 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffc28581630 RCX: 00007f0f86e859c7 RDX: 00007f0f878f6a00 RSI: 0000000000000000 RDI: 000056398e6a99a3 RBP: 00007ffc2857e750 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ffc28581630 R15: 00007ffc2857ec40