INFO: task syz-executor300:9439 blocked for more than 143 seconds. Not tainted 5.6.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor300 D28392 9439 9438 0x20020004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4154 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4213 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x4a2/0x1250 fs/open.c:797 do_last fs/namei.c:3490 [inline] path_openat+0x122a/0x32b0 fs/namei.c:3607 do_filp_open+0x192/0x260 fs/namei.c:3637 do_sys_openat2+0x54c/0x740 fs/open.c:1146 do_sys_open+0xc3/0x140 fs/open.c:1162 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x270/0xe8f arch/x86/entry/common.c:408 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 INFO: task syz-executor300:9440 blocked for more than 143 seconds. Not tainted 5.6.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor300 D28392 9440 9435 0x20024004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4154 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4213 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x4a2/0x1250 fs/open.c:797 do_last fs/namei.c:3490 [inline] path_openat+0x122a/0x32b0 fs/namei.c:3607 do_filp_open+0x192/0x260 fs/namei.c:3637 do_sys_openat2+0x54c/0x740 fs/open.c:1146 do_sys_open+0xc3/0x140 fs/open.c:1162 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x270/0xe8f arch/x86/entry/common.c:408 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 INFO: task syz-executor300:9441 blocked for more than 143 seconds. Not tainted 5.6.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor300 D28336 9441 9437 0x20020004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4154 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4213 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x4a2/0x1250 fs/open.c:797 do_last fs/namei.c:3490 [inline] path_openat+0x122a/0x32b0 fs/namei.c:3607 do_filp_open+0x192/0x260 fs/namei.c:3637 do_sys_openat2+0x54c/0x740 fs/open.c:1146 do_sys_open+0xc3/0x140 fs/open.c:1162 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x270/0xe8f arch/x86/entry/common.c:408 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 INFO: task syz-executor300:9442 blocked for more than 143 seconds. Not tainted 5.6.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor300 D28048 9442 9433 0x20020004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4154 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4213 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x4a2/0x1250 fs/open.c:797 do_last fs/namei.c:3490 [inline] path_openat+0x122a/0x32b0 fs/namei.c:3607 do_filp_open+0x192/0x260 fs/namei.c:3637 do_sys_openat2+0x54c/0x740 fs/open.c:1146 do_sys_open+0xc3/0x140 fs/open.c:1162 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x270/0xe8f arch/x86/entry/common.c:408 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 INFO: task syz-executor300:9443 blocked for more than 143 seconds. Not tainted 5.6.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor300 D28392 9443 9436 0x20020004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4154 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4213 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x7ab/0x13c0 kernel/locking/mutex.c:1103 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x4a2/0x1250 fs/open.c:797 do_last fs/namei.c:3490 [inline] path_openat+0x122a/0x32b0 fs/namei.c:3607 do_filp_open+0x192/0x260 fs/namei.c:3637 do_sys_openat2+0x54c/0x740 fs/open.c:1146 do_sys_open+0xc3/0x140 fs/open.c:1162 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x270/0xe8f arch/x86/entry/common.c:408 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 Showing all locks held in the system: 1 lock held by khungtaskd/1090: #0: ffffffff897accc0 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5331 1 lock held by rsyslogd/9316: #0: ffff88809dd06d60 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:821 2 locks held by getty/9406: #0: ffff88809ece3090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc9000198b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/9407: #0: ffff8880996c1090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900019eb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/9408: #0: ffff88808c89b090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc9000197b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/9409: #0: ffff88809ee2e090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc9000196b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/9410: #0: ffff888092e30090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900019ab2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/9411: #0: ffff88809f958090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900019db2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/9412: #0: ffff88809f578090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc9000178b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by syz-executor300/9434: 1 lock held by syz-executor300/9439: #0: ffff888218c5b070 (&fb_info->lock){+.+.}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff888218c5b070 (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 1 lock held by syz-executor300/9440: #0: ffff888218c5b070 (&fb_info->lock){+.+.}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff888218c5b070 (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 1 lock held by syz-executor300/9441: #0: ffff888218c5b070 (&fb_info->lock){+.+.}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff888218c5b070 (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 1 lock held by syz-executor300/9442: #0: ffff888218c5b070 (&fb_info->lock){+.+.}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff888218c5b070 (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 1 lock held by syz-executor300/9443: #0: ffff888218c5b070 (&fb_info->lock){+.+.}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff888218c5b070 (&fb_info->lock){+.+.}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1090 Comm: khungtaskd Not tainted 5.6.0-rc6-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+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xa8c/0x1010 kernel/hung_task.c:289 kthread+0x357/0x430 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: 9434 Comm: syz-executor300 Not tainted 5.6.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:bitfill_aligned drivers/video/fbdev/core/cfbfillrect.c:62 [inline] RIP: 0010:bitfill_aligned+0xdf/0x200 drivers/video/fbdev/core/cfbfillrect.c:35 Code: fd e8 75 3d bf fd 31 ff 44 89 fe e8 db 3e bf fd 45 85 ff 0f 85 f9 00 00 00 e8 5d 3d bf fd 44 89 e0 31 d2 bf 07 00 00 00 f7 f5 <41> 89 c4 89 c6 89 c5 e8 b5 3e bf fd 41 83 fc 07 76 62 45 89 e7 4c RSP: 0018:ffffc900020273f8 EFLAGS: 00000246 RAX: 0000000000000050 RBX: 0000000000000000 RCX: ffffffff83b2e7b5 RDX: 0000000000000000 RSI: ffffffff83b2e7c3 RDI: 0000000000000007 RBP: 0000000000000040 R08: ffff8880a616e300 R09: 0000000000000040 R10: ffffed104327fb73 R11: ffff8882193fdb9f R12: 0000000000001400 R13: ffff8880000a0000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ae600000(0063) knlGS:0000000009abf840 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 0000000009ac80f4 CR3: 00000000a86f6000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: cfb_fillrect+0x418/0x7a0 drivers/video/fbdev/core/cfbfillrect.c:327 vga16fb_fillrect+0x68f/0x1960 drivers/video/fbdev/vga16fb.c:951 bit_clear_margins+0x2d5/0x4a0 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins+0x1de/0x240 drivers/video/fbdev/core/fbcon.c:1379 fbcon_switch+0xd1b/0x1740 drivers/video/fbdev/core/fbcon.c:2361 redraw_screen+0x2a8/0x770 drivers/tty/vt/vt.c:1008 fbcon_modechanged+0x5bd/0x780 drivers/video/fbdev/core/fbcon.c:2998 fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:3045 fb_set_var+0xad0/0xd40 drivers/video/fbdev/core/fbmem.c:1056 do_fb_ioctl+0x390/0x7d0 drivers/video/fbdev/core/fbmem.c:1109 fb_compat_ioctl+0x305/0xc50 drivers/video/fbdev/core/fbmem.c:1315 __do_compat_sys_ioctl fs/ioctl.c:857 [inline] __se_compat_sys_ioctl fs/ioctl.c:808 [inline] __ia32_compat_sys_ioctl+0x23d/0x2b0 fs/ioctl.c:808 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x270/0xe8f arch/x86/entry/common.c:408 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139