INFO: task syz-executor.2:19976 can't die for more than 143 seconds. task:syz-executor.2 state:D stack:28992 pid:19976 ppid: 6849 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:00007f012609dbf8 EFLAGS: 00000206 ORIG_RAX: 00000000000001a9 RAX: ffffffffffffffda RBX: 00000000200000c0 RCX: 000000000045d5b9 RDX: 0000000020ffe000 RSI: 00000000200000c0 RDI: 00000000000079b6 RBP: 000000000118d038 R08: 0000000020000180 R09: 0000000020000180 R10: 0000000020000140 R11: 0000000000000206 R12: 0000000020ffe000 R13: 0000000020ffc000 R14: 0000000020000180 R15: 0000000020000140 INFO: task syz-executor.2:19976 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:28992 pid:19976 ppid: 6849 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:00007f012609dbf8 EFLAGS: 00000206 ORIG_RAX: 00000000000001a9 RAX: ffffffffffffffda RBX: 00000000200000c0 RCX: 000000000045d5b9 RDX: 0000000020ffe000 RSI: 00000000200000c0 RDI: 00000000000079b6 RBP: 000000000118d038 R08: 0000000020000180 R09: 0000000020000180 R10: 0000000020000140 R11: 0000000000000206 R12: 0000000020ffe000 R13: 0000000020ffc000 R14: 0000000020000180 R15: 0000000020000140 INFO: task io_uring-sq:19978 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:19978 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: ffffffff89c67500 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5829 1 lock held by in:imklog/6535: #0: ffff8880a104b670 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930 2 locks held by agetty/6560: #0: ffff888097008098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:266 #1: ffffc90000fb02e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x223/0x1a30 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1174 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: 2468 Comm: kworker/1:2 Not tainted 5.9.0-rc3-next-20200903-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events nsim_dev_trap_report_work RIP: 0010:check_memory_region+0xe/0x180 mm/kasan/generic.c:191 Code: f5 00 00 00 e9 73 f3 03 02 0f 1f 00 48 89 f2 be f8 00 00 00 e9 63 f3 03 02 0f 1f 00 48 85 f6 0f 84 70 01 00 00 49 89 f9 41 54 <44> 0f b6 c2 49 01 f1 55 53 0f 82 18 01 00 00 48 b8 ff ff ff ff ff RSP: 0018:ffffc90008c4f8a0 EFLAGS: 00000002 RAX: 0000000000000015 RBX: 000000000000054f RCX: ffffffff815a1d47 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8c6aba48 RBP: ffff8880a0562b70 R08: 0000000000000000 R09: ffffffff8c6aba48 R10: fffffbfff18d5749 R11: 00000000c0e81bf2 R12: 0000000000000000 R13: ffff8880a0562b92 R14: ffff8880a05621c0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fccf5d31000 CR3: 0000000090ae8000 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] __lock_acquire+0xf67/0x5570 kernel/locking/lockdep.c:4396 lock_acquire+0x1f3/0xae0 kernel/locking/lockdep.c:5006 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x94/0xce kernel/locking/spinlock.c:159 _crng_backtrack_protect+0x71/0x1a0 drivers/char/random.c:1045 crng_backtrack_protect drivers/char/random.c:1063 [inline] _get_random_bytes+0x295/0x6d0 drivers/char/random.c:1565 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:528 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:558 [inline] nsim_dev_trap_report_work+0x759/0xbe0 drivers/net/netdevsim/dev.c:599 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294