INFO: task syz-executor.2:11118 blocked for more than 143 seconds. Not tainted 5.6.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28264 11118 8783 0x00004004 Call Trace: context_switch kernel/sched/core.c:3380 [inline] __schedule+0x87f/0xcd0 kernel/sched/core.c:4080 schedule+0x188/0x210 kernel/sched/core.c:4154 schedule_timeout+0x46/0x240 kernel/time/timer.c:1871 __down_common+0x28c/0x510 kernel/locking/semaphore.c:220 __down+0x18/0x20 kernel/locking/semaphore.c:237 down+0x6b/0xb0 kernel/locking/semaphore.c:61 console_lock+0x28/0x70 kernel/printk/printk.c:2289 con_shutdown+0x48/0x80 drivers/tty/vt/vt.c:3288 release_tty+0xc1/0x530 drivers/tty/tty_io.c:1514 tty_release_struct+0xc3/0xe0 drivers/tty/tty_io.c:1629 tty_release+0xceb/0xfb0 drivers/tty/tty_io.c:1789 __fput+0x2e4/0x740 fs/file_table.c:280 ____fput+0x15/0x20 fs/file_table.c:313 task_work_run+0x176/0x1b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop arch/x86/entry/common.c:164 [inline] prepare_exit_to_usermode+0x480/0x5b0 arch/x86/entry/common.c:195 syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:278 do_syscall_64+0x11f/0x1c0 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x416011 Code: 49 89 fc 48 83 e7 0f 48 81 cf f0 00 00 00 49 8d 43 04 4c 39 d0 0f 83 ec 00 00 00 41 88 38 90 49 c1 ec 04 48 39 d6 74 5d 49 83 08 73 48 0f b6 02 48 89 cf 4c 89 c9 48 d3 e0 49 09 c4 90 48 8d RSP: 002b:00007fff29731df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 000000000000000e RCX: 0000000000416011 RDX: 0000000000000000 RSI: 000000000000033c RDI: 000000000000000d RBP: 0000000000000001 R08: 0000000076c10340 R09: 00ffffffffffffff R10: 00007fff29731ed0 R11: 0000000000000293 R12: 000000000076c920 R13: 000000000076c920 R14: 0000000000041e13 R15: 000000000076c24c INFO: task syz-executor.4:11166 blocked for more than 143 seconds. Not tainted 5.6.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28248 11166 8791 0x00004004 Call Trace: context_switch kernel/sched/core.c:3380 [inline] __schedule+0x87f/0xcd0 kernel/sched/core.c:4080 schedule+0x188/0x210 kernel/sched/core.c:4154 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:4213 __mutex_lock_common+0x11f1/0x2f30 kernel/locking/mutex.c:1033 __mutex_lock kernel/locking/mutex.c:1103 [inline] mutex_lock_nested+0x1b/0x30 kernel/locking/mutex.c:1118 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0x15e/0x3e0 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x509/0x590 fs/char_dev.c:414 do_dentry_open+0x85b/0x10c0 fs/open.c:797 vfs_open+0x73/0x80 fs/open.c:914 do_last fs/namei.c:3490 [inline] path_openat+0x16f1/0x4380 fs/namei.c:3607 do_filp_open+0x192/0x3d0 fs/namei.c:3637 do_sys_openat2+0x42b/0x6f0 fs/open.c:1149 do_sys_open fs/open.c:1165 [inline] __do_sys_openat fs/open.c:1179 [inline] __se_sys_openat fs/open.c:1174 [inline] __x64_sys_openat+0x1e6/0x210 fs/open.c:1174 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c479 Code: 15 08 c5 01 48 89 04 24 48 8d 44 24 28 48 89 44 24 08 e8 ea 87 fa ff 48 8d 7c 24 78 0f 57 c0 48 8d 7f d0 48 89 6c 24 f0 48 8d <6c> 24 f0 e8 d4 33 00 00 48 8b 6d 00 48 c7 44 24 38 00 00 00 00 66 RSP: 002b:00007f97b4e5dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f97b4e5e6d4 RCX: 000000000045c479 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000799 R14: 00000000004ca0ce R15: 000000000076bf2c INFO: task syz-executor.0:11180 blocked for more than 143 seconds. Not tainted 5.6.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D27816 11180 8774 0x00004004 Call Trace: context_switch kernel/sched/core.c:3380 [inline] __schedule+0x87f/0xcd0 kernel/sched/core.c:4080 schedule+0x188/0x210 kernel/sched/core.c:4154 schedule_timeout+0x46/0x240 kernel/time/timer.c:1871 __down_common+0x28c/0x510 kernel/locking/semaphore.c:220 __down+0x18/0x20 kernel/locking/semaphore.c:237 down+0x6b/0xb0 kernel/locking/semaphore.c:61 console_lock+0x28/0x70 kernel/printk/printk.c:2289 vcs_open+0x67/0xe0 drivers/tty/vt/vc_screen.c:688 chrdev_open+0x509/0x590 fs/char_dev.c:414 do_dentry_open+0x85b/0x10c0 fs/open.c:797 vfs_open+0x73/0x80 fs/open.c:914 do_last fs/namei.c:3490 [inline] path_openat+0x16f1/0x4380 fs/namei.c:3607 do_filp_open+0x192/0x3d0 fs/namei.c:3637 do_sys_openat2+0x42b/0x6f0 fs/open.c:1149 do_sys_open fs/open.c:1165 [inline] ksys_open include/linux/syscalls.h:1386 [inline] __do_sys_open fs/open.c:1171 [inline] __se_sys_open fs/open.c:1169 [inline] __x64_sys_open+0x1bd/0x1e0 fs/open.c:1169 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x416211 Code: 4c 89 f6 49 89 d6 e9 c2 f9 ff ff 48 89 c8 48 89 d3 4d 89 d6 4c 89 f2 31 c9 45 31 ed 45 31 ff 49 89 f2 31 f6 e9 a4 f9 ff ff 49 <8b> 49 08 49 8b 19 4c 89 04 24 89 7c 24 08 89 44 24 0c 48 89 74 24 RSP: 002b:00007f0ab0d217a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 6666666666666667 RCX: 0000000000416211 RDX: 0000000000000000 RSI: 0000000000000101 RDI: 00007f0ab0d21850 RBP: 000000000076bf20 R08: 000000000000000f R09: 0000000000000000 R10: 000000000000fec8 R11: 0000000000000293 R12: 00000000ffffffff R13: 0000000000000c14 R14: 00000000004ce00d R15: 000000000076bf2c INFO: task syz-executor.0:11185 blocked for more than 143 seconds. Not tainted 5.6.0-rc3-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28360 11185 8774 0x00004004 Call Trace: context_switch kernel/sched/core.c:3380 [inline] __schedule+0x87f/0xcd0 kernel/sched/core.c:4080 schedule+0x188/0x210 kernel/sched/core.c:4154 schedule_timeout+0x46/0x240 kernel/time/timer.c:1871 __down_common+0x28c/0x510 kernel/locking/semaphore.c:220 __down+0x18/0x20 kernel/locking/semaphore.c:237 down+0x6b/0xb0 kernel/locking/semaphore.c:61 console_lock+0x28/0x70 kernel/printk/printk.c:2289 vcs_open+0x67/0xe0 drivers/tty/vt/vc_screen.c:688 chrdev_open+0x509/0x590 fs/char_dev.c:414 do_dentry_open+0x85b/0x10c0 fs/open.c:797 vfs_open+0x73/0x80 fs/open.c:914 do_last fs/namei.c:3490 [inline] path_openat+0x16f1/0x4380 fs/namei.c:3607 do_filp_open+0x192/0x3d0 fs/namei.c:3637 do_sys_openat2+0x42b/0x6f0 fs/open.c:1149 do_sys_open fs/open.c:1165 [inline] ksys_open include/linux/syscalls.h:1386 [inline] __do_sys_open fs/open.c:1171 [inline] __se_sys_open fs/open.c:1169 [inline] __x64_sys_open+0x1bd/0x1e0 fs/open.c:1169 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x416211 Code: 4c 89 f6 49 89 d6 e9 c2 f9 ff ff 48 89 c8 48 89 d3 4d 89 d6 4c 89 f2 31 c9 45 31 ed 45 31 ff 49 89 f2 31 f6 e9 a4 f9 ff ff 49 <8b> 49 08 49 8b 19 4c 89 04 24 89 7c 24 08 89 44 24 0c 48 89 74 24 RSP: 002b:00007f0ab0cdf7a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 6666666666666667 RCX: 0000000000416211 RDX: 0000000000000000 RSI: 0000000000000101 RDI: 00007f0ab0cdf850 RBP: 000000000076c060 R08: 000000000000000f R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000293 R12: 00000000ffffffff R13: 0000000000000c14 R14: 00000000004ce00d R15: 000000000076c06c Showing all locks held in the system: 1 lock held by khungtaskd/1120: #0: ffffffff892d9948 (rcu_read_lock){....}, at: rcu_lock_acquire+0x4/0x30 include/linux/rcupdate.h:207 1 lock held by rsyslogd/8642: #0: ffff8880a9521860 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x279/0x310 fs/file.c:821 2 locks held by getty/8732: #0: ffff88808d797090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:267 #1: ffffc9000174b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x22f/0x1bc0 drivers/tty/n_tty.c:2156 2 locks held by getty/8733: #0: ffff888094c9d090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:267 #1: ffffc900017ab2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x22f/0x1bc0 drivers/tty/n_tty.c:2156 2 locks held by getty/8734: #0: ffff8880970bb090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:267 #1: ffffc9000177b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x22f/0x1bc0 drivers/tty/n_tty.c:2156 2 locks held by getty/8735: #0: ffff8880977c1090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:267 #1: ffffc9000173b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x22f/0x1bc0 drivers/tty/n_tty.c:2156 2 locks held by getty/8736: #0: ffff88808c8bd090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:267 #1: ffffc9000179b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x22f/0x1bc0 drivers/tty/n_tty.c:2156 2 locks held by getty/8737: #0: ffff8880a0c76090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:267 #1: ffffc900017032e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x22f/0x1bc0 drivers/tty/n_tty.c:2156 2 locks held by getty/8738: #0: ffff88809a837090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:267 #1: ffffc900016fb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x22f/0x1bc0 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.2/11118: #0: ffffffff89461550 (tty_mutex){+.+.}, at: tty_release_struct+0xb8/0xe0 drivers/tty/tty_io.c:1628 2 locks held by syz-executor.5/11159: 1 lock held by syz-executor.4/11166: #0: ffff8880a38f8070 (&fb_info->lock){+.+.}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a38f8070 (&fb_info->lock){+.+.}, at: fb_open+0x15e/0x3e0 drivers/video/fbdev/core/fbmem.c:1418 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1120 Comm: khungtaskd Not tainted 5.6.0-rc3-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+0x1fb/0x318 lib/dump_stack.c:118 nmi_cpu_backtrace+0xaa/0x190 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x16f/0x290 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace+0x17/0x20 include/linux/nmi.h:146 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xd40/0xd60 kernel/hung_task.c:289 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 11159 Comm: syz-executor.5 Not tainted 5.6.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x50 kernel/kcov.c:180 Code: 0f 0b e8 23 00 00 00 0f 0b 90 55 48 89 e5 53 48 89 fb e8 13 00 00 00 48 8b 3d f4 a1 f2 07 48 89 de e8 84 b4 3c 00 5b 5d c3 cc <55> 48 89 e5 48 8b 45 08 65 48 8b 0c 25 c0 1d 02 00 65 8b 15 34 04 RSP: 0018:ffffc90002e4f798 EFLAGS: 00000286 RAX: ffffffff83d0b788 RBX: 0000000000000038 RCX: 0000000000040000 RDX: ffffc90015885000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: ffffc90002e4f7f0 R08: ffffffff83d0b73d R09: 0000000000000040 R10: ffff88808b7f8440 R11: 0000000000000002 R12: ffff8880000a00b8 R13: 0000000000000000 R14: 0000000000000000 R15: ffffffffffffffff FS: 00007f2f37f18700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f974fa20275 CR3: 00000000a4471000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: cfb_fillrect+0x57b/0x7a0 drivers/video/fbdev/core/cfbfillrect.c:327 vga16fb_fillrect+0x642/0x1470 drivers/video/fbdev/vga16fb.c:951 bit_clear_margins+0x368/0x620 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins drivers/video/fbdev/core/fbcon.c:1379 [inline] fbcon_switch+0x1504/0x1f10 drivers/video/fbdev/core/fbcon.c:2361 redraw_screen+0x56e/0x1830 drivers/tty/vt/vt.c:1008 fbcon_modechanged+0x810/0xdf0 drivers/video/fbdev/core/fbcon.c:2998 fbcon_update_vcs+0x31/0x40 drivers/video/fbdev/core/fbcon.c:3045 fb_set_var+0x8f5/0xdc0 drivers/video/fbdev/core/fbmem.c:1056 do_fb_ioctl+0x55e/0x780 drivers/video/fbdev/core/fbmem.c:1109 fb_ioctl+0xb9/0xf0 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl fs/ioctl.c:763 [inline] __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl+0x113/0x190 fs/ioctl.c:770 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:770 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c479 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:00007f2f37f17c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f2f37f186d4 RCX: 000000000045c479 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000004 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002ef R14: 00000000004c5096 R15: 000000000076bf2c