NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 INFO: task syz-executor.0:9899 blocked for more than 140 seconds. Not tainted 4.19.114-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D27936 9899 6456 0x00000004 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3559 schedule_timeout+0x896/0xf20 kernel/time/timer.c:1782 __down_common kernel/locking/semaphore.c:221 [inline] __down+0x176/0x2c0 kernel/locking/semaphore.c:238 down+0x57/0x80 kernel/locking/semaphore.c:62 console_lock+0x25/0x80 kernel/printk/printk.c:2244 con_flush_chars drivers/tty/vt/vt.c:3209 [inline] con_flush_chars drivers/tty/vt/vt.c:3201 [inline] con_write+0x7c/0xe0 drivers/tty/vt/vt.c:3133 process_output_block drivers/tty/n_tty.c:593 [inline] n_tty_write+0x3ee/0x1080 drivers/tty/n_tty.c:2331 do_tty_write drivers/tty/tty_io.c:960 [inline] tty_write+0x452/0x790 drivers/tty/tty_io.c:1044 do_loop_readv_writev fs/read_write.c:704 [inline] do_loop_readv_writev fs/read_write.c:688 [inline] do_iter_write fs/read_write.c:962 [inline] do_iter_write+0x460/0x5e0 fs/read_write.c:941 vfs_writev+0x1b3/0x2f0 fs/read_write.c:1005 do_writev+0x136/0x330 fs/read_write.c:1040 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c889 Code: 48 83 ec 28 48 89 6c 24 20 48 8d 6c 24 20 48 8b 44 24 38 48 8b 08 48 8b 54 24 30 48 8b 1a 48 39 cb 75 42 0f b6 4a 08 0f b6 58 <08> 38 d9 74 10 31 c0 88 44 24 40 48 8b 6c 24 20 48 83 c4 28 c3 48 RSP: 002b:00007f6805377c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007f68053786d4 RCX: 000000000045c889 RDX: 0000000000000001 RSI: 00000000200005c0 RDI: 0000000000000009 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000d12 R14: 00000000004cb219 R15: 000000000076bf0c INFO: task syz-executor.2:9952 blocked for more than 140 seconds. Not tainted 4.19.114-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D29160 9952 6624 0x00000004 Call Trace: schedule+0x8d/0x1b0 kernel/sched/core.c:3559 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3617 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072 fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457 chrdev_open+0x219/0x5c0 fs/char_dev.c:423 do_dentry_open+0x4a8/0x1160 fs/open.c:796 do_last fs/namei.c:3421 [inline] path_openat+0x1031/0x4200 fs/namei.c:3537 do_filp_open+0x1a1/0x280 fs/namei.c:3567 do_sys_open+0x3c0/0x500 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c889 Code: 48 83 ec 28 48 89 6c 24 20 48 8d 6c 24 20 48 8b 44 24 38 48 8b 08 48 8b 54 24 30 48 8b 1a 48 39 cb 75 42 0f b6 4a 08 0f b6 58 <08> 38 d9 74 10 31 c0 88 44 24 40 48 8b 6c 24 20 48 83 c4 28 c3 48 RSP: 002b:00007f3546450c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f35464516d4 RCX: 000000000045c889 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000076c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000798 R14: 00000000004ca4f4 R15: 000000000076c04c Showing all locks held in the system: 1 lock held by khungtaskd/1079: #0: 00000000844f08a3 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4436 1 lock held by in:imklog/6123: #0: 00000000ac3e59f2 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:767 4 locks held by syz-executor.0/9899: #0: 0000000090bd29d6 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 000000006ffc77a6 (&tty->atomic_write_lock){+.+.}, at: tty_write_lock+0x1e/0x80 drivers/tty/tty_io.c:886 #2: 000000000c78f37f (&tty->termios_rwsem){++++}, at: n_tty_write+0x1b2/0x1080 drivers/tty/n_tty.c:2314 #3: 00000000326fec39 (&ldata->output_lock){+.+.}, at: process_output_block drivers/tty/n_tty.c:548 [inline] #3: 00000000326fec39 (&ldata->output_lock){+.+.}, at: n_tty_write+0x505/0x1080 drivers/tty/n_tty.c:2331 3 locks held by syz-executor.2/9905: 1 lock held by syz-executor.2/9952: #0: 000000000b412f9b (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1079 Comm: khungtaskd Not tainted 4.19.114-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+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x962/0xe40 kernel/hung_task.c:287 kthread+0x34a/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 9905 Comm: syz-executor.2 Not tainted 4.19.114-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x50 kernel/kcov.c:106 Code: 65 8b 15 4c 49 9a 7e 81 e2 00 01 1f 00 75 2b 8b 90 d0 12 00 00 83 fa 02 75 20 48 8b 88 d8 12 00 00 8b 80 d4 12 00 00 48 8b 11 <48> 83 c2 01 48 39 d0 76 07 48 89 34 d1 48 89 11 c3 0f 1f 84 00 00 RSP: 0018:ffff88803a7072c0 EFLAGS: 00000246 RAX: 0000000000040000 RBX: 0000000000000050 RCX: ffffc90009efa000 RDX: 000000000003ffff RSI: ffffffff837a10f6 RDI: 0000000000000004 RBP: 0000000000000043 R08: ffff888039a0a700 R09: ffffed1014a8c27c R10: ffffed1014a8c27b R11: ffff8880a54613df R12: ffff8880000a0043 R13: ffff8880000a0000 R14: 0000000000000000 R15: 00000000ef506bc0 FS: 00007f3546493700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c43fb532d0 CR3: 0000000097d41000 CR4: 00000000001406e0 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+0x9c6/0x1960 drivers/video/fbdev/vga16fb.c:923 bit_clear_margins+0x2d5/0x4a0 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins+0x2d8/0x370 drivers/video/fbdev/core/fbcon.c:1339 fbcon_switch+0xe0f/0x1970 drivers/video/fbdev/core/fbcon.c:2321 redraw_screen+0x37d/0x870 drivers/tty/vt/vt.c:1009 fbcon_modechanged+0x5eb/0x8f0 drivers/video/fbdev/core/fbcon.c:2969 fbcon_event_notify+0x1b2/0x1d54 drivers/video/fbdev/core/fbcon.c:3344 notifier_call_chain+0xc0/0x230 kernel/notifier.c:93 __blocking_notifier_call_chain kernel/notifier.c:317 [inline] __blocking_notifier_call_chain kernel/notifier.c:304 [inline] blocking_notifier_call_chain kernel/notifier.c:328 [inline] blocking_notifier_call_chain+0x85/0xa0 kernel/notifier.c:325 fb_set_var+0xc39/0xe00 drivers/video/fbdev/core/fbmem.c:1042 do_fb_ioctl+0x450/0xab0 drivers/video/fbdev/core/fbmem.c:1115 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1230 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcda/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c889 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f3546492c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f35464936d4 RCX: 000000000045c889 RDX: 0000000020000340 RSI: 0000000000004601 RDI: 0000000000000004 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002ee R14: 00000000004c54bc R15: 000000000076bf0c