INFO: task syz-executor.4:2115 blocked for more than 140 seconds. Not tainted 4.9.202+ #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D25016 2115 1 0x00000004 0000000000000083 ffff8801d43d17c0 ffff8801d4c5c780 ffff8801db61ffc0 ffff8801a2195f00 ffff8801db61ffd8 ffff8801a41df688 ffffffff8280a1de ffff8801d43d17c0 ffffffff841f6b00 00ff8801a41df5e8 ffff8801db6208b0 Call Trace: [<000000007417a445>] schedule+0x92/0x1c0 kernel/sched/core.c:3546 [<00000000515cf1b3>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3579 [<0000000043311372>] __mutex_lock_common kernel/locking/mutex.c:582 [inline] [<0000000043311372>] mutex_lock_nested+0x38d/0x920 kernel/locking/mutex.c:621 [<000000006b03ec82>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 [<0000000055491eb7>] __blkdev_get+0x268/0xeb0 fs/block_dev.c:1287 [<000000007a36ed03>] blkdev_get+0x2e8/0x920 fs/block_dev.c:1424 [<00000000f3dc0df4>] blkdev_open+0x1aa/0x250 fs/block_dev.c:1579 [<00000000b4edc918>] do_dentry_open+0x422/0xd20 fs/open.c:791 [<00000000dd151d2d>] vfs_open+0x105/0x230 fs/open.c:904 [<00000000d72d2ec3>] do_last fs/namei.c:3457 [inline] [<00000000d72d2ec3>] path_openat+0xbf5/0x2f60 fs/namei.c:3581 [<00000000077b0475>] do_filp_open+0x1a1/0x280 fs/namei.c:3615 [<0000000013507ff5>] do_sys_open+0x2f0/0x610 fs/open.c:1097 [<000000003ec521e7>] SYSC_open fs/open.c:1115 [inline] [<000000003ec521e7>] SyS_open+0x2d/0x40 fs/open.c:1110 [<000000004a9ebda9>] do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288 [<00000000e12a906c>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Showing all locks held in the system: 2 locks held by khungtaskd/24: #0: (rcu_read_lock){......}, at: [<000000006bb88b30>] check_hung_uninterruptible_tasks kernel/hung_task.c:169 [inline] #0: (rcu_read_lock){......}, at: [<000000006bb88b30>] watchdog+0x14b/0xaf0 kernel/hung_task.c:263 #1: (tasklist_lock){.+.+..}, at: [<0000000011c80329>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4339 1 lock held by rsyslogd/1897: #0: (&f->f_pos_lock){+.+.+.}, at: [<000000008fdc79c5>] __fdget_pos+0xa8/0xd0 fs/file.c:782 2 locks held by getty/2025: #0: (&tty->ldisc_sem){++++++}, at: [<000000005c50c8a4>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+...}, at: [<0000000063ee6647>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.4/2115: #0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000fcb88b9e>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<000000006b03ec82>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 2 locks held by syz-executor.5/2117: #0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000fcb88b9e>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<000000006b03ec82>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 2 locks held by syz-executor.1/2120: #0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000fcb88b9e>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<000000006b03ec82>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 2 locks held by syz-executor.2/4394: #0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000fcb88b9e>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<000000006b03ec82>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 2 locks held by syz-executor.3/5021: #0: (loop_index_mutex){+.+.+.}, at: [<0000000047bc6ee2>] loop_control_ioctl+0x7a/0x320 drivers/block/loop.c:1974 #1: (&lo->lo_ctl_mutex#2){+.+.+.}, at: [<00000000bc3b23b3>] loop_control_ioctl+0x17f/0x320 drivers/block/loop.c:1988 1 lock held by syz-executor.3/5029: #0: (loop_index_mutex){+.+.+.}, at: [<0000000047bc6ee2>] loop_control_ioctl+0x7a/0x320 drivers/block/loop.c:1974 1 lock held by syz-executor.3/5031: #0: (loop_index_mutex){+.+.+.}, at: [<0000000047bc6ee2>] loop_control_ioctl+0x7a/0x320 drivers/block/loop.c:1974 1 lock held by syz-executor.3/5032: #0: (loop_index_mutex){+.+.+.}, at: [<0000000047bc6ee2>] loop_control_ioctl+0x7a/0x320 drivers/block/loop.c:1974 1 lock held by syz-executor.3/5037: #0: (loop_index_mutex){+.+.+.}, at: [<0000000047bc6ee2>] loop_control_ioctl+0x7a/0x320 drivers/block/loop.c:1974 2 locks held by syz-executor.0/5003: #0: (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<000000006d91c0b6>] lo_ioctl+0x8e/0x1b10 drivers/block/loop.c:1404 #1: (&bdev->bd_mutex){+.+.+.}, at: [<000000003818dce6>] blkdev_reread_part+0x1f/0x40 block/ioctl.c:189 1 lock held by syz-executor.0/5017: #0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000fcb88b9e>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 2 locks held by blkid/5025: #0: (&bdev->bd_mutex){+.+.+.}, at: [<00000000fcb88b9e>] __blkdev_get+0x10e/0xeb0 fs/block_dev.c:1273 #1: (loop_index_mutex){+.+.+.}, at: [<000000006b03ec82>] lo_open+0x1d/0xb0 drivers/block/loop.c:1622 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.202+ #0 ffff8801d98f7cc8 ffffffff81b55d2b 0000000000000001 0000000000000000 0000000000000001 ffffffff8109a001 dffffc0000000000 ffff8801d98f7d00 ffffffff81b60fcc 0000000000000001 0000000000000000 0000000000000001 Call Trace: [<00000000d6c01fda>] __dump_stack lib/dump_stack.c:15 [inline] [<00000000d6c01fda>] dump_stack+0xcb/0x130 lib/dump_stack.c:56 [<00000000c16d8e3b>] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99 [<00000000faaa94b6>] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60 [<0000000050f2fd24>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [<00000000c6832c7d>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [<00000000c6832c7d>] check_hung_task kernel/hung_task.c:126 [inline] [<00000000c6832c7d>] check_hung_uninterruptible_tasks kernel/hung_task.c:183 [inline] [<00000000c6832c7d>] watchdog+0x670/0xaf0 kernel/hung_task.c:263 [<00000000416a83c6>] kthread+0x278/0x310 kernel/kthread.c:211 [<00000000535cf6cd>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:375 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.9.202+ #0 task: 000000001ec4b58d task.stack: 00000000f3f1a802 RIP: 0010:[] c [<00000000773329b8>] __msecs_to_jiffies+0x0/0x50 kernel/time/time.c:522 RSP: 0018:ffff8801db607db8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff83031a30 RDX: 0000000000000002 RSI: ffffffff81bbc38c RDI: 0000000000000002 RBP: ffff8801db607ea0 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff83031a30 R11: 0000000000000001 R12: ffff8801da4836d0 R13: ffff8801da483680 R14: 0000000000006462 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2ac51bc000 CR3: 00000001d4c8c000 CR4: 00000000001606b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff811d71fec ffffffff811d6ef5c ffffffff83c4fc48c 0000000041b58ab3c ffffffff82e2e270c ffff8801da4836e0c 1ffff1003b6c0fc3c 0000000000000000c 00000001000049c6c 0000000000000000c ffff8801db61ffc0c fffffbfff0601200c Call Trace: [<00000000cd278ae7>] run_rebalance_domains+0x2f0/0x500 kernel/sched/fair.c:10461 [<000000009acc7030>] __do_softirq+0x22d/0x964 kernel/softirq.c:288 [<00000000d35248ac>] invoke_softirq kernel/softirq.c:368 [inline] [<00000000d35248ac>] irq_exit+0x119/0x160 kernel/softirq.c:409 [<00000000303aa703>] smp_reschedule_interrupt+0x6e/0x90 arch/x86/kernel/smp.c:278 [<00000000d4e63e6e>] reschedule_interrupt+0xa5/0xb0 arch/x86/entry/entry_64.S:676 d [<000000006feee42c>] ? native_safe_halt+0x41/0x60 arch/x86/include/asm/irqflags.h:59 [<00000000b297e004>] arch_safe_halt arch/x86/include/asm/paravirt.h:104 [inline] [<00000000b297e004>] default_idle+0x56/0x370 arch/x86/kernel/process.c:500 [<000000005d17a947>] arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:491 [<00000000385ddbfb>] default_idle_call+0x36/0x60 kernel/sched/idle.c:97 [<00000000b7ffcb86>] cpuidle_idle_call kernel/sched/idle.c:155 [inline] [<00000000b7ffcb86>] cpu_idle_loop kernel/sched/idle.c:248 [inline] [<00000000b7ffcb86>] cpu_startup_entry+0x283/0x3a0 kernel/sched/idle.c:303 [<000000009173cda4>] rest_init+0x18b/0x194 init/main.c:409 [<0000000008f9489f>] start_kernel+0x61e/0x652 init/main.c:671 [<0000000088ed9478>] x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:196 [<00000000ad1a11f2>] x86_64_start_kernel+0x137/0x15a arch/x86/kernel/head64.c:177 Code: cfa c48 cc1 cea c03 c80 c3c c02 c00 c75 c15 c49 c89 c5d c08 c5b c41 c5c c41 c5d c5d cc3 c4c c89 cef ce8 cfd cf0 c29 c00 ceb ccc ce8 cf6 cf0 c29 c00 ceb ce4 c0f c1f c40 c00 c<55> c48 c89 ce5 c41 c54 c49 cbc cfe cff cff cff cff cff cff c3f c53 c89 cfb ce8 c68 c