Buffer I/O error on dev loop0p1, logical block 0, async page read blk_update_request: I/O error, dev loop0, sector 0 Buffer I/O error on dev loop0p1, logical block 0, async page read Buffer I/O error on dev loop0p1, logical block 0, async page read INFO: task init:16285 blocked for more than 140 seconds. Not tainted 4.9.189+ #22 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. init D28056 16285 1 0x00000000 0000000000000087 ffff8801d72bc740 ffff8801a3f09080 ffff8801db621000 ffff8801a4e9df00 ffff8801db621018 ffff8801cdf47758 ffffffff8281887e ffff8801d72bd008 ffff8801d72bcfe0 00ff8801d72bd010 ffff8801db6218f0 Call Trace: [<000000005ee86a86>] schedule+0x92/0x1c0 kernel/sched/core.c:3546 [<00000000eb6935c3>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3579 [<00000000d02401ef>] __mutex_lock_common kernel/locking/mutex.c:582 [inline] [<00000000d02401ef>] mutex_lock_nested+0x38d/0x920 kernel/locking/mutex.c:621 [<000000000cebc1d4>] tty_open_by_driver drivers/tty/tty_io.c:2062 [inline] [<000000000cebc1d4>] tty_open+0x3f9/0xe10 drivers/tty/tty_io.c:2140 [<000000002db88559>] chrdev_open+0x230/0x630 fs/char_dev.c:398 [<0000000028915bd5>] do_dentry_open+0x422/0xd20 fs/open.c:791 [<0000000050218782>] vfs_open+0x105/0x230 fs/open.c:904 [<0000000029928d3d>] do_last fs/namei.c:3457 [inline] [<0000000029928d3d>] path_openat+0xbf5/0x2f60 fs/namei.c:3581 [<0000000077482c02>] do_filp_open+0x1a1/0x280 fs/namei.c:3615 [<00000000f430646a>] do_sys_open+0x2f0/0x610 fs/open.c:1097 [<00000000c0c26345>] SYSC_open fs/open.c:1115 [inline] [<00000000c0c26345>] SyS_open+0x2d/0x40 fs/open.c:1110 [<00000000830af245>] do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288 [<000000007ca2d2ff>] 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: [<00000000ed1b27de>] check_hung_uninterruptible_tasks kernel/hung_task.c:169 [inline] #0: (rcu_read_lock){......}, at: [<00000000ed1b27de>] watchdog+0x14b/0xaf0 kernel/hung_task.c:263 #1: (tasklist_lock){.+.+..}, at: [<00000000ccd902b3>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4336 1 lock held by rsyslogd/1893: #0: (&f->f_pos_lock){+.+.+.}, at: [<00000000ef7f237d>] __fdget_pos+0xa8/0xd0 fs/file.c:782 2 locks held by getty/2021: #0: (&tty->ldisc_sem){++++++}, at: [<00000000f09fd8b7>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+...}, at: [<00000000cbb8b09a>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156 4 locks held by kworker/u4:2/2095: #0: ("%s""netns"){.+.+.+}, at: [<0000000021b23f12>] process_one_work+0x790/0x1600 kernel/workqueue.c:2107 #1: (net_cleanup_work){+.+.+.}, at: [<00000000c64d67c5>] process_one_work+0x7ce/0x1600 kernel/workqueue.c:2111 #2: (net_mutex){+.+.+.}, at: [<00000000ad647913>] cleanup_net+0x131/0x8a0 net/core/net_namespace.c:440 #3: (rcu_preempt_state.barrier_mutex){+.+...}, at: [<0000000055543d10>] _rcu_barrier+0x5d/0x340 kernel/rcu/tree.c:3645 1 lock held by init/16285: #0: (tty_mutex){+.+.+.}, at: [<000000000cebc1d4>] tty_open_by_driver drivers/tty/tty_io.c:2062 [inline] #0: (tty_mutex){+.+.+.}, at: [<000000000cebc1d4>] tty_open+0x3f9/0xe10 drivers/tty/tty_io.c:2140 1 lock held by init/16286: #0: (tty_mutex){+.+.+.}, at: [<000000000cebc1d4>] tty_open_by_driver drivers/tty/tty_io.c:2062 [inline] #0: (tty_mutex){+.+.+.}, at: [<000000000cebc1d4>] tty_open+0x3f9/0xe10 drivers/tty/tty_io.c:2140 1 lock held by init/16287: #0: (tty_mutex){+.+.+.}, at: [<000000000cebc1d4>] tty_open_by_driver drivers/tty/tty_io.c:2062 [inline] #0: (tty_mutex){+.+.+.}, at: [<000000000cebc1d4>] tty_open+0x3f9/0xe10 drivers/tty/tty_io.c:2140 1 lock held by init/16288: #0: (tty_mutex){+.+.+.}, at: [<000000000cebc1d4>] tty_open_by_driver drivers/tty/tty_io.c:2062 [inline] #0: (tty_mutex){+.+.+.}, at: [<000000000cebc1d4>] tty_open+0x3f9/0xe10 drivers/tty/tty_io.c:2140 1 lock held by init/17021: #0: (tty_mutex){+.+.+.}, at: [<000000000cebc1d4>] tty_open_by_driver drivers/tty/tty_io.c:2062 [inline] #0: (tty_mutex){+.+.+.}, at: [<000000000cebc1d4>] tty_open+0x3f9/0xe10 drivers/tty/tty_io.c:2140 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.189+ #22 ffff8801d98d7cc8 ffffffff81b65c01 0000000000000001 0000000000000000 0000000000000001 ffffffff81099a01 dffffc0000000000 ffff8801d98d7d00 ffffffff81b70e9c 0000000000000001 0000000000000000 0000000000000001 Call Trace: [<0000000092e3feef>] __dump_stack lib/dump_stack.c:15 [inline] [<0000000092e3feef>] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [<000000006c9c917a>] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99 [<00000000a2cf0876>] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60 [<00000000124ae55f>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [<00000000f7d695f9>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [<00000000f7d695f9>] check_hung_task kernel/hung_task.c:126 [inline] [<00000000f7d695f9>] check_hung_uninterruptible_tasks kernel/hung_task.c:183 [inline] [<00000000f7d695f9>] watchdog+0x670/0xaf0 kernel/hung_task.c:263 [<000000007a7472b0>] kthread+0x278/0x310 kernel/kthread.c:211 [<000000004929493d>] 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: 28578 Comm: syz-executor.3 Not tainted 4.9.189+ #22 task: 00000000edec784e task.stack: 00000000c81554e2 RIP: 0010:[] c [<000000001803cbf0>] tun_chr_read_iter+0x0/0x200 drivers/net/tun.c:1526 RSP: 0018:ffff8801a6b17ca0 EFLAGS: 00000246 RAX: ffffffff81ef8920 RBX: ffff8801a6b17dd0 RCX: 1ffff1003a27a55c RDX: 1ffffffff0579e68 RSI: ffff8801a6b17d60 RDI: ffff8801a6b17d10 RBP: ffff8801a6b17df8 R08: 00000000000003e8 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000003 R12: ffffffff82bcf320 R13: ffff8801a6b17e88 R14: 00000000000003e8 R15: ffff8801a6b17d60 FS: 00000000015a0940(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000625208 CR3: 00000001a627b000 CR4: 00000000001606b0 Stack: ffffffff8151395ec 0002000081a28520c ffff8801d70198a8c ffff8801d2cd5e28c ffffffff00008802c 1ffff10034d62f9ac 0000000041b58ab3c ffffffff82e407c0c ffffffff815135a0c ffffffff815f0160c 00007fffebd09d70c 00000000000003e8c Call Trace: [<00000000d9b0f37c>] vfs_read+0x137/0x380 fs/read_write.c:474 [<00000000b601943a>] SYSC_read fs/read_write.c:591 [inline] [<00000000b601943a>] SyS_read+0x121/0x270 fs/read_write.c:584 [<00000000830af245>] do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288 [<000000007ca2d2ff>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Code: ce9 c1f cff cff cff ce8 cb1 c5b c60 cff ce9 ce2 cfe cff cff ce8 ca7 c5b c60 cff ce9 c01 cff cff cff ce8 c9d c5b c60 cff ce9 c87 cfe cff cff ce8 c93 c5b c60 cff ceb ca0 c90 c<55> c48 c89 ce5 c41 c57 c41 c56 c41 c55 c49 c89 cf5 c41 c54 c49 c89 cfc c53 c48 c83 c