INFO: task syz-executor.4:20349 blocked for more than 143 seconds. Not tainted 5.6.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28456 20349 7366 0x80004004 Call Trace: context_switch kernel/sched/core.c:3380 [inline] __schedule+0x7c9/0xc50 kernel/sched/core.c:4080 schedule+0x188/0x220 kernel/sched/core.c:4154 schedule_timeout+0x43/0x240 kernel/time/timer.c:1871 mark_held_locks kernel/locking/lockdep.c:3359 [inline] __trace_hardirqs_on_caller kernel/locking/lockdep.c:3388 [inline] lockdep_hardirqs_on+0x4f4/0x840 kernel/locking/lockdep.c:3433 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199 do_wait_for_common+0x2c7/0x4c0 kernel/sched/completion.c:83 console_conditional_schedule+0x30/0x30 do_task_dead+0xb0/0xb0 kernel/sched/core.c:4098 __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x43/0x50 kernel/sched/completion.c:136 io_queue_file_removal fs/io_uring.c:5840 [inline] __io_sqe_files_update+0x483/0xbe0 fs/io_uring.c:5881 io_sqe_files_update fs/io_uring.c:5932 [inline] __io_uring_register fs/io_uring.c:7145 [inline] __do_sys_io_uring_register fs/io_uring.c:7216 [inline] __se_sys_io_uring_register+0x7d8/0x3010 fs/io_uring.c:7198 fdput_pos include/linux/file.h:80 [inline] ksys_write+0x1ab/0x220 fs/read_write.c:614 debug_smp_processor_id+0x5/0x20 lib/smp_processor_id.c:56 arch_static_branch arch/x86/include/asm/jump_label.h:25 [inline] static_key_false include/linux/jump_label.h:200 [inline] trace_irq_disable_rcuidle+0x1f/0x1d0 include/trace/events/preemptirq.h:36 entry_SYSCALL_64_after_hwframe+0x3e/0xbe do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe INFO: task syz-executor.2:20391 blocked for more than 143 seconds. Not tainted 5.6.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28456 20391 7262 0x80004004 Call Trace: context_switch kernel/sched/core.c:3380 [inline] __schedule+0x7c9/0xc50 kernel/sched/core.c:4080 schedule+0x188/0x220 kernel/sched/core.c:4154 schedule_timeout+0x43/0x240 kernel/time/timer.c:1871 mark_held_locks kernel/locking/lockdep.c:3359 [inline] __trace_hardirqs_on_caller kernel/locking/lockdep.c:3388 [inline] lockdep_hardirqs_on+0x4f4/0x840 kernel/locking/lockdep.c:3433 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199 do_wait_for_common+0x2c7/0x4c0 kernel/sched/completion.c:83 console_conditional_schedule+0x30/0x30 do_task_dead+0xb0/0xb0 kernel/sched/core.c:4098 __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x43/0x50 kernel/sched/completion.c:136 io_queue_file_removal fs/io_uring.c:5840 [inline] __io_sqe_files_update+0x483/0xbe0 fs/io_uring.c:5881 io_sqe_files_update fs/io_uring.c:5932 [inline] __io_uring_register fs/io_uring.c:7145 [inline] __do_sys_io_uring_register fs/io_uring.c:7216 [inline] __se_sys_io_uring_register+0x7d8/0x3010 fs/io_uring.c:7198 fdput_pos include/linux/file.h:80 [inline] ksys_write+0x1ab/0x220 fs/read_write.c:614 debug_smp_processor_id+0x5/0x20 lib/smp_processor_id.c:56 arch_static_branch arch/x86/include/asm/jump_label.h:25 [inline] static_key_false include/linux/jump_label.h:200 [inline] trace_irq_disable_rcuidle+0x1f/0x1d0 include/trace/events/preemptirq.h:36 entry_SYSCALL_64_after_hwframe+0x3e/0xbe do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe Showing all locks held in the system: 1 lock held by khungtaskd/1131: #0: ffffffff890d9ac8 (rcu_read_lock){....}, at: rcu_lock_acquire+0x0/0x30 lib/xarray.c:75 1 lock held by in:imklog/6602: 2 locks held by rs:main Q:Reg/6603: 2 locks held by agetty/6587: #0: ffff8880937aa090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:267 #1: ffffc900010902e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x25d/0x1bc0 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.4/20349: #0: ffff88808e1ac320 (&ctx->uring_lock){+.+.}, at: __do_sys_io_uring_register fs/io_uring.c:7215 [inline] #0: ffff88808e1ac320 (&ctx->uring_lock){+.+.}, at: __se_sys_io_uring_register+0xf7/0x3010 fs/io_uring.c:7198 1 lock held by syz-executor.2/20391: #0: ffff88809a680320 (&ctx->uring_lock){+.+.}, at: __do_sys_io_uring_register fs/io_uring.c:7215 [inline] #0: ffff88809a680320 (&ctx->uring_lock){+.+.}, at: __se_sys_io_uring_register+0xf7/0x3010 fs/io_uring.c:7198 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1131 Comm: khungtaskd Not tainted 5.6.0-rc7-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+0x1e9/0x30e lib/dump_stack.c:118 nmi_cpu_backtrace+0x9f/0x180 lib/nmi_backtrace.c:101 arch_trigger_cpumask_backtrace+0x10/0x10 arch/x86/kernel/apic/hw_nmi.c:38 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xd2a/0xd40 kernel/hung_task.c:289 kthread+0x317/0x340 kernel/kthread.c:255 hungtask_pm_notify+0x50/0x50 kernel/hung_task.c:265 kthread_blkcg+0xd0/0xd0 kernel/kthread.c:1234 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 6603 Comm: rs:main Q:Reg Not tainted 5.6.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_kcov_mode kernel/kcov.c:164 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x22/0x50 kernel/kcov.c:187 Code: 00 cc cc cc cc cc cc cc 48 8b 04 24 65 48 8b 0c 25 c0 1d 02 00 65 8b 15 98 87 8d 7e f7 c2 00 01 1f 00 75 2c 8b 91 80 13 00 00 <83> fa 02 75 21 48 8b 91 88 13 00 00 48 8b 32 48 8d 7e 01 8b 89 84 RSP: 0018:ffffc900071d7598 EFLAGS: 00000046 RAX: ffffffff814e453e RBX: 0000000000000000 RCX: ffff88808fed25c0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffff814e4535 R09: ffffed1015d07004 R10: ffffed1015d07004 R11: 0000000000000000 R12: ffffe8ffffc0ea00 R13: dffffc0000000000 R14: ffff8880a0d26880 R15: 1ffffd1ffff81d4b FS: 00007fe24ae27700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f34635f6000 CR3: 00000000a2f70000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_unlock_sched_notrace include/linux/rcupdate.h:739 [inline] trace_workqueue_activate_work+0x23e/0x280 include/trace/events/workqueue.h:59 __queue_work+0x85d/0xc60 kernel/workqueue.c:1478 mod_delayed_work_on+0x73/0x180 kernel/workqueue.c:1709 kblockd_mod_delayed_work_on+0x25/0x30 block/blk-core.c:1669 blk_mq_run_hw_queue+0x17c/0x330 block/blk-mq.c:1512 blk_mq_sched_insert_request+0x2ad/0x5d0 block/blk-mq-sched.c:440 blk_mq_make_request+0x8ec/0x1890 block/blk-mq.c:2038 generic_make_request+0x24b/0x980 block/blk-core.c:1069 submit_bio+0x26b/0x540 block/blk-core.c:1195 submit_bh fs/buffer.c:3118 [inline] __sync_dirty_buffer+0x19b/0x2d0 fs/buffer.c:3204 ext4_write_inode+0x356/0x5b0 fs/ext4/inode.c:5132 write_inode fs/fs-writeback.c:1312 [inline] __writeback_single_inode+0x568/0x630 fs/fs-writeback.c:1511 writeback_single_inode+0x1b1/0x7d0 fs/fs-writeback.c:1565 sync_mapping_buffers+0x58c/0xdb0 fs/buffer.c:560 sync_inode fs/fs-writeback.c:2602 [inline] sync_inode_metadata+0x6d/0xb0 fs/fs-writeback.c:2622 ext4_fsync_nojournal fs/ext4/fsync.c:94 [inline] ext4_sync_file+0x49c/0x830 fs/ext4/fsync.c:172 generic_write_sync include/linux/fs.h:2868 [inline] ext4_buffered_write_iter+0x52e/0x5d0 fs/ext4/file.c:277 ext4_file_write_iter+0x6c1/0x1840 fs/ext4/file.c:491 iov_iter_init+0x83/0x160 lib/iov_iter.c:448 call_write_iter include/linux/fs.h:1902 [inline] new_sync_write fs/read_write.c:483 [inline] __vfs_write+0x549/0x710 fs/read_write.c:496 vfs_write+0x271/0x570 fs/read_write.c:558 ksys_write+0x115/0x220 fs/read_write.c:611 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7fe24d86b1cd Code: c2 20 00 00 75 10 b8 01 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ae fc ff ff 48 89 04 24 b8 01 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 f7 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007fe24ae26590 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fe24002a750 RCX: 00007fe24d86b1cd RDX: 00000000000003fc RSI: 00007fe24002a750 RDI: 000000000000000a RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007fe24002a4d0 R13: 00007fe24ae265b0 R14: 000055e9c78df7c0 R15: 00000000000003fc