INFO: task syz-executor.0:7743 blocked for more than 143 seconds. Not tainted 5.5.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29632 7743 10596 0x00004004 Call Trace: context_switch kernel/sched/core.c:3386 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4082 schedule+0xdc/0x2b0 kernel/sched/core.c:4156 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1871 __down_common kernel/locking/semaphore.c:220 [inline] __down+0x176/0x2c0 kernel/locking/semaphore.c:237 down+0x64/0x90 kernel/locking/semaphore.c:61 console_lock+0x29/0x80 kernel/printk/printk.c:2289 do_fb_ioctl+0x335/0x7d0 drivers/video/fbdev/core/fbmem.c:1106 fb_ioctl+0xe6/0x130 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x123/0x180 fs/ioctl.c:747 __do_sys_ioctl fs/ioctl.c:756 [inline] __se_sys_ioctl fs/ioctl.c:754 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45b399 Code: 48 89 44 24 08 c6 44 24 10 01 e8 32 0a fb ff 48 8b 44 24 18 83 3d 26 b5 bf 01 00 75 12 48 8b 4c 24 20 48 89 01 48 8b 6c 24 28 <48> 83 c4 30 c3 48 8b 7c 24 20 e8 58 39 00 00 eb ea 48 05 7f fc ff RSP: 002b:00007fedf0b05c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fedf0b066d4 RCX: 000000000045b399 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000006 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002ea R14: 00000000004c3f9a R15: 000000000075bfd4 INFO: task syz-executor.0:7748 blocked for more than 143 seconds. Not tainted 5.5.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29704 7748 10596 0x00004004 Call Trace: context_switch kernel/sched/core.c:3386 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4082 schedule+0xdc/0x2b0 kernel/sched/core.c:4156 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4215 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118 lock_fb_info include/linux/fb.h:637 [inline] do_fb_ioctl+0x1b5/0x7d0 drivers/video/fbdev/core/fbmem.c:1168 fb_ioctl+0xe6/0x130 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x123/0x180 fs/ioctl.c:747 __do_sys_ioctl fs/ioctl.c:756 [inline] __se_sys_ioctl fs/ioctl.c:754 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45b399 Code: 48 89 44 24 08 c6 44 24 10 01 e8 32 0a fb ff 48 8b 44 24 18 83 3d 26 b5 bf 01 00 75 12 48 8b 4c 24 20 48 89 01 48 8b 6c 24 28 <48> 83 c4 30 c3 48 8b 7c 24 20 e8 58 39 00 00 eb ea 48 05 7f fc ff RSP: 002b:00007fedf0ae4c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fedf0ae56d4 RCX: 000000000045b399 RDX: 0000000020000040 RSI: 00000000c0506617 RDI: 0000000000000006 RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000030c R14: 00000000004d18a8 R15: 000000000075c07c INFO: task syz-executor.0:7752 blocked for more than 143 seconds. Not tainted 5.5.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28360 7752 10596 0x00004004 Call Trace: context_switch kernel/sched/core.c:3386 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4082 schedule+0xdc/0x2b0 kernel/sched/core.c:4156 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4215 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x245/0x6b0 fs/char_dev.c:414 do_dentry_open+0x4e6/0x1380 fs/open.c:797 vfs_open+0xa0/0xd0 fs/open.c:914 do_last fs/namei.c:3490 [inline] path_openat+0x12ee/0x3490 fs/namei.c:3607 do_filp_open+0x192/0x260 fs/namei.c:3637 do_sys_openat2+0x5eb/0x7e0 fs/open.c:1149 do_sys_open+0xf2/0x180 fs/open.c:1165 __do_sys_openat fs/open.c:1179 [inline] __se_sys_openat fs/open.c:1174 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1174 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45b399 Code: 48 89 44 24 08 c6 44 24 10 01 e8 32 0a fb ff 48 8b 44 24 18 83 3d 26 b5 bf 01 00 75 12 48 8b 4c 24 20 48 89 01 48 8b 6c 24 28 <48> 83 c4 30 c3 48 8b 7c 24 20 e8 58 39 00 00 eb ea 48 05 7f fc ff RSP: 002b:00007fedf0ac3c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fedf0ac46d4 RCX: 000000000045b399 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000075c118 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000794 R14: 00000000004c8fd2 R15: 000000000075c124 INFO: task syz-executor.0:7785 blocked for more than 143 seconds. Not tainted 5.5.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28360 7785 10596 0x00004004 Call Trace: context_switch kernel/sched/core.c:3386 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4082 schedule+0xdc/0x2b0 kernel/sched/core.c:4156 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4215 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1118 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x245/0x6b0 fs/char_dev.c:414 do_dentry_open+0x4e6/0x1380 fs/open.c:797 vfs_open+0xa0/0xd0 fs/open.c:914 do_last fs/namei.c:3490 [inline] path_openat+0x12ee/0x3490 fs/namei.c:3607 do_filp_open+0x192/0x260 fs/namei.c:3637 do_sys_openat2+0x5eb/0x7e0 fs/open.c:1149 do_sys_open+0xf2/0x180 fs/open.c:1165 __do_sys_openat fs/open.c:1179 [inline] __se_sys_openat fs/open.c:1174 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1174 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45b399 Code: 48 89 44 24 08 c6 44 24 10 01 e8 32 0a fb ff 48 8b 44 24 18 83 3d 26 b5 bf 01 00 75 12 48 8b 4c 24 20 48 89 01 48 8b 6c 24 28 <48> 83 c4 30 c3 48 8b 7c 24 20 e8 58 39 00 00 eb ea 48 05 7f fc ff RSP: 002b:00007fedf0a81c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fedf0a826d4 RCX: 000000000045b399 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000075c268 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000794 R14: 00000000004c8fd2 R15: 000000000075c274 Showing all locks held in the system: 1 lock held by khungtaskd/481: #0: ffffffff89baa840 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5333 1 lock held by rsyslogd/10429: #0: ffff888099dd9420 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:821 2 locks held by getty/10551: #0: ffff8880979ea090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900018ab2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/10552: #0: ffff8880a3a53090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900018eb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/10553: #0: ffff88809a947090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900018db2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/10554: #0: ffff8880a8490090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000186b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/10555: #0: ffff88809ae62090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc900018fb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/10556: #0: ffff88809d745090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000189b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/10557: #0: ffff888090574090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc9000183b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.0/7741: 1 lock held by syz-executor.0/7748: #0: ffff888218dc9070 (&fb_info->lock){+.+.}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff888218dc9070 (&fb_info->lock){+.+.}, at: do_fb_ioctl+0x1b5/0x7d0 drivers/video/fbdev/core/fbmem.c:1168 1 lock held by syz-executor.0/7752: #0: ffff888218dc9070 (&fb_info->lock){+.+.}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff888218dc9070 (&fb_info->lock){+.+.}, at: fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1418 1 lock held by syz-executor.0/7785: #0: ffff888218dc9070 (&fb_info->lock){+.+.}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff888218dc9070 (&fb_info->lock){+.+.}, at: fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1418 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 481 Comm: khungtaskd Not tainted 5.5.0-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+0x197/0x210 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xb11/0x10c0 kernel/hung_task.c:289 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7741 Comm: syz-executor.0 Not tainted 5.5.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_kcov_mode kernel/kcov.c:153 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x14/0x50 kernel/kcov.c:187 Code: 8b 80 98 13 00 00 c3 0f 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 65 48 8b 04 25 c0 1e 02 00 65 8b 15 34 e9 8c 7e <81> e2 00 01 1f 00 48 8b 75 08 75 2b 8b 90 80 13 00 00 83 fa 02 75 RSP: 0018:ffffc900029e7528 EFLAGS: 00000212 RAX: ffff88808fb445c0 RBX: 0000000000000050 RCX: ffffffff83c93040 RDX: 0000000080000000 RSI: 0000000000000050 RDI: 0000000000000004 RBP: ffffc900029e7528 R08: ffff88808fb445c0 R09: ffffed10431ca81c R10: ffffed10431ca81b R11: ffff888218e540df R12: 000000000000002d R13: ffff8880000a002d R14: ffff8880000a0000 R15: 0000000000000000 FS: 00007fedf0b27700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc806017000 CR3: 0000000093d50000 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+0xa0a/0x19b0 drivers/video/fbdev/vga16fb.c:923 bit_clear_margins+0x30b/0x530 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins+0x1e9/0x250 drivers/video/fbdev/core/fbcon.c:1379 fbcon_switch+0xd7f/0x17f0 drivers/video/fbdev/core/fbcon.c:2361 redraw_screen+0x2b6/0x7d0 drivers/tty/vt/vt.c:997 fbcon_modechanged+0x5c3/0x790 drivers/video/fbdev/core/fbcon.c:2998 fbcon_update_vcs+0x42/0x50 drivers/video/fbdev/core/fbcon.c:3045 fb_set_var+0xb32/0xdd0 drivers/video/fbdev/core/fbmem.c:1056 do_fb_ioctl+0x390/0x7d0 drivers/video/fbdev/core/fbmem.c:1109 fb_ioctl+0xe6/0x130 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x123/0x180 fs/ioctl.c:747 __do_sys_ioctl fs/ioctl.c:756 [inline] __se_sys_ioctl fs/ioctl.c:754 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45b399 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:00007fedf0b26c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fedf0b276d4 RCX: 000000000045b399 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000009 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002ea R14: 00000000004c3f9a R15: 000000000075bf2c