INFO: task syz-executor.1:29382 blocked for more than 140 seconds. Not tainted 4.19.126-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D29072 29382 22928 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x8a2/0x1fc0 kernel/sched/core.c:3515 schedule+0x8d/0x1b0 kernel/sched/core.c:3559 schedule_timeout+0x8f3/0xed0 kernel/time/timer.c:1782 __down_common kernel/locking/semaphore.c:221 [inline] __down+0x192/0x2b0 kernel/locking/semaphore.c:238 down+0x57/0x80 kernel/locking/semaphore.c:62 console_lock+0x25/0x80 kernel/printk/printk.c:2244 vcs_open+0x62/0xc0 drivers/tty/vt/vc_screen.c:660 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+0xe06/0x2eb0 fs/namei.c:3537 do_filp_open+0x1a1/0x280 fs/namei.c:3567 do_sys_open+0x3aa/0x510 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x416861 Code: 00 00 00 e8 61 10 05 00 48 89 d8 b9 28 00 00 00 e8 54 10 05 00 48 89 d8 b9 28 00 00 00 e8 47 10 05 00 48 89 d8 b9 28 00 00 00 3a 10 05 00 48 89 f0 b9 28 00 00 00 e8 2d 10 05 00 48 89 f0 b9 RSP: 002b:00007f32a91677a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 6666666666666667 RCX: 0000000000416861 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f32a9167850 RBP: 000000000078bf00 R08: 000000000000000f R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00000000ffffffff R13: 0000000000000c21 R14: 00000000004ce731 R15: 00007f32a91686d4 INFO: task syz-executor.1:29386 blocked for more than 140 seconds. Not tainted 4.19.126-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D27744 29386 22928 0x80000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x8a2/0x1fc0 kernel/sched/core.c:3515 schedule+0x8d/0x1b0 kernel/sched/core.c:3559 schedule_timeout+0x8f3/0xed0 kernel/time/timer.c:1782 __down_common kernel/locking/semaphore.c:221 [inline] __down+0x192/0x2b0 kernel/locking/semaphore.c:238 down+0x57/0x80 kernel/locking/semaphore.c:62 console_lock+0x25/0x80 kernel/printk/printk.c:2244 do_con_write.part.0+0xa8/0x1db0 drivers/tty/vt/vt.c:2576 do_con_write drivers/tty/vt/vt.c:2571 [inline] con_write+0x41/0xe0 drivers/tty/vt/vt.c:3138 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+0x455/0x790 drivers/tty/tty_io.c:1044 __vfs_write+0xf7/0x760 fs/read_write.c:485 __kernel_write+0x109/0x370 fs/read_write.c:506 write_pipe_buf+0x153/0x1e0 fs/splice.c:798 splice_from_pipe_feed fs/splice.c:503 [inline] __splice_from_pipe+0x38f/0x7a0 fs/splice.c:627 splice_from_pipe+0xd9/0x140 fs/splice.c:662 default_file_splice_write+0x37/0x90 fs/splice.c:810 do_splice_from fs/splice.c:852 [inline] direct_splice_actor+0x115/0x160 fs/splice.c:1025 splice_direct_to_actor+0x33f/0x8d0 fs/splice.c:980 do_splice_direct+0x1a8/0x270 fs/splice.c:1068 do_sendfile+0x549/0xc10 fs/read_write.c:1447 __do_sys_sendfile64 fs/read_write.c:1508 [inline] __se_sys_sendfile64+0x147/0x160 fs/read_write.c:1494 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45ca69 Code: 48 c7 44 24 10 00 00 00 00 48 8b 44 24 68 48 89 44 24 18 48 8b 44 24 70 48 89 44 24 20 48 8b 44 24 78 48 89 44 24 28 48 89 4c <24> 30 0f 57 c0 0f 11 44 24 38 48 c7 44 24 48 00 00 00 00 e8 0f d4 RSP: 002b:00007f32a9125c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00000000004fc580 RCX: 000000000045ca69 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000003 RBP: 000000000078c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0800000080004103 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000008dc R14: 00000000004cba56 R15: 00007f32a91266d4 INFO: task syz-executor.3:29408 blocked for more than 140 seconds. Not tainted 4.19.126-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D29456 29408 13103 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x8a2/0x1fc0 kernel/sched/core.c:3515 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+0x5b8/0x1300 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+0xe06/0x2eb0 fs/namei.c:3537 do_filp_open+0x1a1/0x280 fs/namei.c:3567 do_sys_open+0x3aa/0x510 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45ca69 Code: 48 c7 44 24 10 00 00 00 00 48 8b 44 24 68 48 89 44 24 18 48 8b 44 24 70 48 89 44 24 20 48 8b 44 24 78 48 89 44 24 28 48 89 4c <24> 30 0f 57 c0 0f 11 44 24 38 48 c7 44 24 48 00 00 00 00 e8 0f d4 RSP: 002b:00007f89be0a3c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00000000004f7680 RCX: 000000000045ca69 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000078c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000007a0 R14: 00000000004ca784 R15: 00007f89be0a46d4 INFO: task syz-executor.0:29393 blocked for more than 140 seconds. Not tainted 4.19.126-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28464 29393 18243 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x8a2/0x1fc0 kernel/sched/core.c:3515 schedule+0x8d/0x1b0 kernel/sched/core.c:3559 schedule_timeout+0x8f3/0xed0 kernel/time/timer.c:1782 __down_common kernel/locking/semaphore.c:221 [inline] __down+0x192/0x2b0 kernel/locking/semaphore.c:238 down+0x57/0x80 kernel/locking/semaphore.c:62 console_lock+0x25/0x80 kernel/printk/printk.c:2244 vcs_open+0x62/0xc0 drivers/tty/vt/vc_screen.c:660 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+0xe06/0x2eb0 fs/namei.c:3537 do_filp_open+0x1a1/0x280 fs/namei.c:3567 do_sys_open+0x3aa/0x510 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x416861 Code: 00 00 00 e8 61 10 05 00 48 89 d8 b9 28 00 00 00 e8 54 10 05 00 48 89 d8 b9 28 00 00 00 e8 47 10 05 00 48 89 d8 b9 28 00 00 00 3a 10 05 00 48 89 f0 b9 28 00 00 00 e8 2d 10 05 00 48 89 f0 b9 RSP: 002b:00007f478cdfc7a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 6666666666666667 RCX: 0000000000416861 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007f478cdfc850 RBP: 000000000078bf00 R08: 000000000000000f R09: 0000000000000000 R10: 0000000000000004 R11: 0000000000000293 R12: 00000000ffffffff R13: 0000000000000c21 R14: 00000000004ce731 R15: 00007f478cdfd6d4 Showing all locks held in the system: 1 lock held by khungtaskd/1080: #0: 000000005bcbe8a0 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4440 1 lock held by in:imklog/6139: #0: 00000000e0ce4b6c (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:767 4 locks held by syz-executor.1/29386: #0: 00000000f1301012 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:272 #1: 000000005a1e332f (&tty->atomic_write_lock){+.+.}, at: tty_write_lock+0x1e/0x80 drivers/tty/tty_io.c:886 #2: 00000000f67732db (&tty->termios_rwsem){++++}, at: n_tty_write+0x1b2/0x1080 drivers/tty/n_tty.c:2314 #3: 00000000e3724162 (&ldata->output_lock){+.+.}, at: process_output_block drivers/tty/n_tty.c:548 [inline] #3: 00000000e3724162 (&ldata->output_lock){+.+.}, at: n_tty_write+0x505/0x1080 drivers/tty/n_tty.c:2331 3 locks held by syz-executor.3/29381: 1 lock held by syz-executor.3/29408: #0: 000000003ffb0613 (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1457 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1080 Comm: khungtaskd Not tainted 4.19.126-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+0x1fc/0x2fe 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+0x30b/0x410 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 29381 Comm: syz-executor.3 Not tainted 4.19.126-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_pc+0x22/0x50 kernel/kcov.c:101 Code: 00 00 e9 24 ec ff ff 90 48 8b 34 24 65 48 8b 04 25 40 ee 01 00 65 8b 15 ec 62 9a 7e 81 e2 00 01 1f 00 75 2b 8b 90 d8 12 00 00 <83> fa 02 75 20 48 8b 88 e0 12 00 00 8b 80 dc 12 00 00 48 8b 11 48 RSP: 0018:ffff8880558c72b8 EFLAGS: 00000246 RAX: ffff888062fa0700 RBX: 0000000000000004 RCX: ffffffff837af556 RDX: 0000000000000002 RSI: ffffffff837af50f RDI: 0000000000000005 RBP: 0000000000000004 R08: ffff888062fa0700 R09: ffffed10432d3db4 R10: ffffed10432d3db3 R11: ffff88821969ed9f R12: ffff8880000a0004 R13: ffff8880000a0000 R14: 0000000000000000 R15: 000000002be77a26 FS: 00007f89be0e6700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c007149000 CR3: 000000004e76c000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vga16fb_fillrect+0x9af/0x1960 drivers/video/fbdev/vga16fb.c:922 bit_clear_margins+0x2d5/0x4a0 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins+0x2c7/0x350 drivers/video/fbdev/core/fbcon.c:1342 fbcon_switch+0xd9f/0x18f0 drivers/video/fbdev/core/fbcon.c:2324 redraw_screen+0x37d/0x870 drivers/tty/vt/vt.c:1015 fbcon_modechanged+0x5a0/0x870 drivers/video/fbdev/core/fbcon.c:2972 fbcon_event_notify+0x1b2/0x1d60 drivers/video/fbdev/core/fbcon.c:3347 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+0x450/0x9c0 drivers/video/fbdev/core/fbmem.c:1115 fb_ioctl+0xda/0x120 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: 0033:0x45ca69 Code: 0d b7 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f89be0e5c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e4b00 RCX: 000000000045ca69 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000004 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002f2 R14: 00000000004c5708 R15: 00007f89be0e66d4