INFO: task syz-executor.0:22839 blocked for more than 140 seconds. Not tainted 4.14.184-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29280 22839 6348 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893 tty_open_by_driver drivers/tty/tty_io.c:1937 [inline] tty_open+0x321/0x860 drivers/tty/tty_io.c:2021 chrdev_open+0x1fc/0x540 fs/char_dev.c:423 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0xb68/0x2aa0 fs/namei.c:3569 do_filp_open+0x18e/0x250 fs/namei.c:3603 do_sys_open+0x292/0x3e0 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x415f51 RSP: 002b:00007fb6d902d820 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000000000078bfa0 RCX: 0000000000415f51 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007fb6d902d850 RBP: 000000000078bfe0 R08: 0000000000000000 R09: 000000000000000d R10: 0000000000000064 R11: 0000000000000293 R12: 000000000078bfac R13: 00007ffdd0d88d0f R14: 00007fb6d902e9c0 R15: 000000000078bfac INFO: task syz-executor.0:22850 blocked for more than 140 seconds. Not tainted 4.14.184-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29280 22850 6348 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893 tty_open_by_driver drivers/tty/tty_io.c:1937 [inline] tty_open+0x321/0x860 drivers/tty/tty_io.c:2021 chrdev_open+0x1fc/0x540 fs/char_dev.c:423 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0xb68/0x2aa0 fs/namei.c:3569 do_filp_open+0x18e/0x250 fs/namei.c:3603 do_sys_open+0x292/0x3e0 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x415f51 RSP: 002b:00007fb6d8feb820 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000000000078c0e0 RCX: 0000000000415f51 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007fb6d8feb850 RBP: 000000000078c120 R08: 0000000000000000 R09: 000000000000000d R10: 0000000000000064 R11: 0000000000000293 R12: 000000000078c0ec R13: 00007ffdd0d88d0f R14: 00007fb6d8fec9c0 R15: 000000000078c0ec INFO: task syz-executor.5:22837 blocked for more than 140 seconds. Not tainted 4.14.184-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28928 22837 6352 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x86c/0xe50 kernel/time/timer.c:1723 __down_common kernel/locking/semaphore.c:221 [inline] __down+0x17f/0x280 kernel/locking/semaphore.c:238 down+0x57/0x80 kernel/locking/semaphore.c:62 console_lock+0x24/0x70 kernel/printk/printk.c:2216 con_shutdown+0x3d/0x90 drivers/tty/vt/vt.c:2941 release_tty+0xba/0x750 drivers/tty/tty_io.c:1501 tty_release_struct+0x37/0x50 drivers/tty/tty_io.c:1616 tty_release+0xaa8/0xd60 drivers/tty/tty_io.c:1776 __fput+0x25f/0x7a0 fs/file_table.c:210 task_work_run+0x113/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1ad/0x200 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x415d51 RSP: 002b:00007ffdf534da30 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000415d51 RDX: 0000001b30520000 RSI: 00000000000009b7 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00000000f5f069bb R09: 0000000000000000 R10: 00007ffdf534db20 R11: 0000000000000293 R12: 0000000000790260 R13: 00000000000898fa R14: ffffffffffffffff R15: 000000000078bf0c INFO: task syz-executor.3:22849 blocked for more than 140 seconds. Not tainted 4.14.184-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28784 22849 6354 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893 tty_open_by_driver drivers/tty/tty_io.c:1937 [inline] tty_open+0x321/0x860 drivers/tty/tty_io.c:2021 chrdev_open+0x1fc/0x540 fs/char_dev.c:423 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0xb68/0x2aa0 fs/namei.c:3569 do_filp_open+0x18e/0x250 fs/namei.c:3603 do_sys_open+0x292/0x3e0 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x415f51 RSP: 002b:00007f2818647820 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000000000078bfa0 RCX: 0000000000415f51 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007f2818647850 RBP: 000000000078bfe0 R08: 0000000000000000 R09: 000000000000000d R10: 0000000000000064 R11: 0000000000000293 R12: 000000000078bfac R13: 00007fff724fd55f R14: 00007f28186489c0 R15: 000000000078bfac INFO: task syz-executor.1:22864 blocked for more than 140 seconds. Not tainted 4.14.184-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28816 22864 15945 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893 tty_open_by_driver drivers/tty/tty_io.c:1937 [inline] tty_open+0x321/0x860 drivers/tty/tty_io.c:2021 chrdev_open+0x1fc/0x540 fs/char_dev.c:423 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0xb68/0x2aa0 fs/namei.c:3569 do_filp_open+0x18e/0x250 fs/namei.c:3603 do_sys_open+0x292/0x3e0 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x415f51 RSP: 002b:00007f6589054820 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000000000078bf00 RCX: 0000000000415f51 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007f6589054850 RBP: 000000000078bf40 R08: 0000000000000000 R09: 000000000000000e R10: 0000000000000064 R11: 0000000000000293 R12: 000000000078bf0c R13: 00007ffe271af1bf R14: 00007f65890559c0 R15: 000000000078bf0c INFO: task syz-executor.1:22867 blocked for more than 140 seconds. Not tainted 4.14.184-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D29584 22867 15945 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3486 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x5f0/0x1430 kernel/locking/mutex.c:893 tty_open_by_driver drivers/tty/tty_io.c:1937 [inline] tty_open+0x321/0x860 drivers/tty/tty_io.c:2021 chrdev_open+0x1fc/0x540 fs/char_dev.c:423 do_dentry_open+0x44b/0xec0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:888 do_last fs/namei.c:3428 [inline] path_openat+0xb68/0x2aa0 fs/namei.c:3569 do_filp_open+0x18e/0x250 fs/namei.c:3603 do_sys_open+0x292/0x3e0 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x415f51 RSP: 002b:00007f6589012820 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 000000000078c040 RCX: 0000000000415f51 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00007f6589012850 RBP: 000000000078c080 R08: 0000000000000000 R09: 000000000000000e R10: 0000000000000064 R11: 0000000000000293 R12: 000000000078c04c R13: 00007ffe271af1bf R14: 00007f65890139c0 R15: 000000000078c04c Showing all locks held in the system: 1 lock held by khungtaskd/1052: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 1 lock held by in:imklog/5994: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0xa6/0xc0 fs/file.c:769 2 locks held by agetty/6025: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16e0 drivers/tty/n_tty.c:2156 2 locks held by agetty/6032: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16e0 drivers/tty/n_tty.c:2156 2 locks held by agetty/6037: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16e0 drivers/tty/n_tty.c:2156 2 locks held by agetty/6043: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e4/0x16e0 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.0/10401: #0: (tty_mutex){+.+.}, at: [] tty_release_struct+0x2c/0x50 drivers/tty/tty_io.c:1615 1 lock held by syz-executor.5/19304: #0: (tty_mutex){+.+.}, at: [] tty_release_struct+0x2c/0x50 drivers/tty/tty_io.c:1615 1 lock held by syz-executor.0/20777: #0: (tty_mutex){+.+.}, at: [] tty_release_struct+0x2c/0x50 drivers/tty/tty_io.c:1615 1 lock held by syz-executor.0/22839: #0: (tty_mutex){+.+.}, at: [] tty_open_by_driver drivers/tty/tty_io.c:1937 [inline] #0: (tty_mutex){+.+.}, at: [] tty_open+0x321/0x860 drivers/tty/tty_io.c:2021 1 lock held by syz-executor.0/22850: #0: (tty_mutex){+.+.}, at: [] tty_open_by_driver drivers/tty/tty_io.c:1937 [inline] #0: (tty_mutex){+.+.}, at: [] tty_open+0x321/0x860 drivers/tty/tty_io.c:2021 1 lock held by syz-executor.5/22837: #0: (tty_mutex){+.+.}, at: [] tty_release_struct+0x2c/0x50 drivers/tty/tty_io.c:1615 1 lock held by syz-executor.3/22849: #0: (tty_mutex){+.+.}, at: [] tty_open_by_driver drivers/tty/tty_io.c:1937 [inline] #0: (tty_mutex){+.+.}, at: [] tty_open+0x321/0x860 drivers/tty/tty_io.c:2021 1 lock held by syz-executor.1/22864: #0: (tty_mutex){+.+.}, at: [] tty_open_by_driver drivers/tty/tty_io.c:1937 [inline] #0: (tty_mutex){+.+.}, at: [] tty_open+0x321/0x860 drivers/tty/tty_io.c:2021 1 lock held by syz-executor.1/22867: #0: (tty_mutex){+.+.}, at: [] tty_open_by_driver drivers/tty/tty_io.c:1937 [inline] #0: (tty_mutex){+.+.}, at: [] tty_open+0x321/0x860 drivers/tty/tty_io.c:2021 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1052 Comm: khungtaskd Not tainted 4.14.184-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x283 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x17f lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5e2/0xb80 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 22816 Comm: syz-executor.2 Not tainted 4.14.184-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff88804923e600 task.stack: ffff8880965e8000 RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x50 kernel/kcov.c:60 RSP: 0018:ffff8880965ef1b8 EFLAGS: 00000287 RAX: 0000000000040000 RBX: ffff8880000a0050 RCX: ffffc90007f1c000 RDX: 0000000000040000 RSI: ffffffff831f9ef3 RDI: ffff8880965ef270 RBP: 0000000000000050 R08: ffffed1014bf8ef4 R09: 0000000000000004 R10: ffffed1014bf8ef3 R11: ffff8880a5fc779f R12: ffff8880000a003e R13: 0000000000000000 R14: 00000000e70e9080 R15: 000000000000004f FS: 00007f5b2d47b700(0000) GS:ffff8880aec00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000560eb23c8cf8 CR3: 000000008be7a000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: writeb arch/x86/include/asm/io.h:65 [inline] vga16fb_fillrect+0x943/0x1880 drivers/video/fbdev/vga16fb.c:923 bit_clear_margins+0x2a4/0x480 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins+0x274/0x300 drivers/video/fbdev/core/fbcon.c:1320 ypan_up_redraw drivers/video/fbdev/core/fbcon.c:1505 [inline] fbcon_scroll+0xcd6/0x33c0 drivers/video/fbdev/core/fbcon.c:1883 con_scroll+0x294/0x310 drivers/tty/vt/vt.c:327 lf+0x226/0x270 drivers/tty/vt/vt.c:1134 do_con_trol+0x493/0x52e0 drivers/tty/vt/vt.c:1797 do_con_write.part.0+0xc44/0x1a20 drivers/tty/vt/vt.c:2447 do_con_write drivers/tty/vt/vt.c:2218 [inline] con_write+0x33/0xc0 drivers/tty/vt/vt.c:2798 do_output_char+0x4f5/0x750 drivers/tty/n_tty.c:447 process_output drivers/tty/n_tty.c:514 [inline] n_tty_write+0x409/0xe20 drivers/tty/n_tty.c:2345 do_tty_write drivers/tty/tty_io.c:959 [inline] tty_write+0x3f1/0x6e0 drivers/tty/tty_io.c:1043 __vfs_write+0xe4/0x630 fs/read_write.c:480 __kernel_write+0xf5/0x330 fs/read_write.c:501 write_pipe_buf+0x143/0x1b0 fs/splice.c:797 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0x332/0x740 fs/splice.c:626 splice_from_pipe+0xc6/0x120 fs/splice.c:661 default_file_splice_write+0x37/0x80 fs/splice.c:809 do_splice_from fs/splice.c:851 [inline] direct_splice_actor+0x115/0x160 fs/splice.c:1018 splice_direct_to_actor+0x27e/0x730 fs/splice.c:973 do_splice_direct+0x164/0x210 fs/splice.c:1061 do_sendfile+0x469/0xaf0 fs/read_write.c:1441 SYSC_sendfile64 fs/read_write.c:1502 [inline] SyS_sendfile64+0xff/0x110 fs/read_write.c:1488 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45c1d9 RSP: 002b:00007f5b2d47ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 0000000000025a00 RCX: 000000000045c1d9 RDX: 0000000000000000 RSI: 000000000000000b RDI: 000000000000000a RBP: 000000000078bf48 R08: 0000000000000000 R09: 0000000000000000 R10: 0800000080004103 R11: 0000000000000246 R12: 000000000078bf0c R13: 00007ffe13850a1f R14: 00007f5b2d47b9c0 R15: 000000000078bf0c Code: 00 48 c7 c7 c0 94 8d 86 4c 89 3d 3c f2 dd 08 41 bd f4 ff ff ff e8 9c de ee ff 48 c7 05 26 f2 dd 08 00 00 00 00 e9 be ed ff ff 90 <65> 48 8b 04 25 40 ee 01 00 48 85 c0 74 1a 65 8b 15 db 47 a7 7e