INFO: task syz-executor174:6866 blocked for more than 143 seconds. Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor174 state:D stack:28104 pid: 6866 ppid: 6860 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:00007ffc22bf79f8 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440299 RDX: 0000000000400b40 RSI: 0000000020000080 RDI: 0000000000006ad4 RBP: 00000000006ca018 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000401aa0 R13: 0000000000401b30 R14: 0000000000000000 R15: 0000000000000000 INFO: task io_uring-sq:6867 blocked for more than 143 seconds. Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:io_uring-sq state:D stack:31200 pid: 6867 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/1164: #0: ffffffff89c67980 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5829 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1164 Comm: khungtaskd Not tainted 5.9.0-rc3-next-20200902-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: 3898 Comm: systemd-journal Not tainted 5.9.0-rc3-next-20200902-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:90 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:108 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:134 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:165 [inline] RIP: 0010:check_memory_region_inline mm/kasan/generic.c:183 [inline] RIP: 0010:check_memory_region+0xcd/0x180 mm/kasan/generic.c:192 Code: 8d 50 08 eb 09 48 83 c0 01 48 39 d0 74 7a 80 38 00 74 f2 48 89 c2 b8 01 00 00 00 48 85 d2 75 56 5b 5d 41 5c c3 48 85 d2 74 5e <48> 01 ea eb 09 48 83 c0 01 48 39 d0 74 50 80 38 00 74 f2 eb d4 41 RSP: 0018:ffffc90000f77a88 EFLAGS: 00000002 RAX: fffffbfff18d573c RBX: fffffbfff18d573d RCX: ffffffff8159e9fc RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffff8c6ab9e0 RBP: fffffbfff18d573c R08: 0000000000000000 R09: ffffffff8c6ab9e7 R10: fffffbfff18d573c R11: 0000000000000000 R12: 0000000000000008 R13: ffff888093bf8c1a R14: ffff888093bf8bf8 R15: ffff888093bf8bd0 FS: 00007f111719e8c0(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1114541000 CR3: 000000009368d000 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] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] hlock_class kernel/locking/lockdep.c:179 [inline] mark_lock+0xbc/0x1710 kernel/locking/lockdep.c:3983 mark_usage kernel/locking/lockdep.c:3931 [inline] __lock_acquire+0x88e/0x5570 kernel/locking/lockdep.c:4380 lock_acquire+0x1f3/0xae0 kernel/locking/lockdep.c:5006 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 devkmsg_read+0x1d0/0xa50 kernel/printk/printk.c:762 vfs_read+0x1df/0x5a0 fs/read_write.c:479 ksys_read+0x12d/0x250 fs/read_write.c:607 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f111672e210 Code: 73 01 c3 48 8b 0d 98 7d 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d b9 c1 20 00 00 75 10 b8 00 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 4e fc ff ff 48 89 04 24 RSP: 002b:00007fff926b28f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007fff926b5370 RCX: 00007f111672e210 RDX: 0000000000002000 RSI: 00007fff926b3170 RDI: 0000000000000009 RBP: 0000000000000000 R08: 0000000000000008 R09: 00007fff926f80f0 R10: 0000000000011db0 R11: 0000000000000246 R12: 00007fff926b3170 R13: 00007fff926b52c8 R14: 000056138774a958 R15: 0005ae621e1f9d6d