INFO: task syz-executor.4:14885 can't die for more than 143 seconds. task:syz-executor.4 state:D stack:29752 pid:14885 ppid: 6852 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:00007fecfd69ebf8 EFLAGS: 00000206 ORIG_RAX: 00000000000001a9 RAX: ffffffffffffffda RBX: 0000000020000240 RCX: 000000000045d5b9 RDX: 00000000206d5000 RSI: 0000000020000240 RDI: 0000000000007e71 RBP: 000000000118d038 R08: 0000000020000100 R09: 0000000020000100 R10: 0000000020000040 R11: 0000000000000206 R12: 00000000206d5000 R13: 00000000206d4000 R14: 0000000020000100 R15: 0000000020000040 INFO: task syz-executor.4:14885 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-executor.4 state:D stack:29752 pid:14885 ppid: 6852 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:00007fecfd69ebf8 EFLAGS: 00000206 ORIG_RAX: 00000000000001a9 RAX: ffffffffffffffda RBX: 0000000020000240 RCX: 000000000045d5b9 RDX: 00000000206d5000 RSI: 0000000020000240 RDI: 0000000000007e71 RBP: 000000000118d038 R08: 0000000020000100 R09: 0000000020000100 R10: 0000000020000040 R11: 0000000000000206 R12: 00000000206d5000 R13: 00000000206d4000 R14: 0000000020000100 R15: 0000000020000040 INFO: task io_uring-sq:14887 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:31120 pid:14887 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/1174: #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: 1174 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 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60