INFO: task syz-executor.3:20813 blocked for more than 143 seconds. Not tainted 5.6.0-rc3-next-20200228-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D27320 20813 9505 0x80004002 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4152 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4211 __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_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1447 __fput+0x2da/0x850 fs/file_table.c:280 task_work_run+0x13f/0x1b0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xb53/0x2e10 kernel/exit.c:802 do_group_exit+0x125/0x340 kernel/exit.c:900 get_signal+0x47b/0x24e0 kernel/signal.c:2739 do_signal+0x7e/0x13f0 arch/x86/kernel/signal.c:813 exit_to_usermode_loop+0x26c/0x360 arch/x86/entry/common.c:161 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x672/0x790 arch/x86/entry/common.c:305 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c679 Code: cc 64 48 8b 0c 25 f8 ff ff ff 48 3b 61 10 0f 86 8f 00 00 00 48 83 ec 68 48 89 6c 24 60 48 8d 6c 24 60 48 8b 5a 10 48 8b 72 18 <48> 8b 7a 20 4c 8b 42 40 4c 8b 4a 08 48 8b 4a 30 48 8b 52 28 48 85 RSP: 002b:00007f9a66d07c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: 0000000000000006 RBX: 00007f9a66d086d4 RCX: 000000000045c679 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000076bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000799 R14: 00000000004ca2eb R15: 000000000076bfac INFO: task syz-executor.0:20818 can't die for more than 143 seconds. syz-executor.0 D28304 20818 9491 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4152 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4211 __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_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1447 __fput+0x2da/0x850 fs/file_table.c:280 task_work_run+0x13f/0x1b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x2fa/0x360 arch/x86/entry/common.c:165 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x672/0x790 arch/x86/entry/common.c:305 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:00007ffffca682a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000416211 RDX: 0000000000000000 RSI: 000000000000161d RDI: 0000000000000004 RBP: 0000000000000001 R08: 00000000a47b561d R09: 00000000a47b5621 R10: 00007ffffca68380 R11: 0000000000000293 R12: 000000000076c900 R13: 000000000076c900 R14: 000000000007d3e9 R15: 000000000076c04c INFO: task syz-executor.0:20818 blocked for more than 143 seconds. Not tainted 5.6.0-rc3-next-20200228-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28304 20818 9491 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4152 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4211 __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_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1447 __fput+0x2da/0x850 fs/file_table.c:280 task_work_run+0x13f/0x1b0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x2fa/0x360 arch/x86/entry/common.c:165 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x672/0x790 arch/x86/entry/common.c:305 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:00007ffffca682a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000416211 RDX: 0000000000000000 RSI: 000000000000161d RDI: 0000000000000004 RBP: 0000000000000001 R08: 00000000a47b561d R09: 00000000a47b5621 R10: 00007ffffca68380 R11: 0000000000000293 R12: 000000000076c900 R13: 000000000076c900 R14: 000000000007d3e9 R15: 000000000076c04c INFO: task syz-executor.5:20833 can't die for more than 143 seconds. syz-executor.5 R running task 27216 20833 9510 0x00004006 Call Trace: Showing all locks held in the system: 1 lock held by khungtaskd/1134: #0: ffffffff899adc80 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5544 1 lock held by rsyslogd/9362: #0: ffff8880a0786ba0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:821 2 locks held by getty/9452: #0: ffff88809ad26090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900019332e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/9453: #0: ffff8880a6936090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900019532e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/9454: #0: ffff88809fbe5090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900019232e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/9455: #0: ffff888099989090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900019832e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/9456: #0: ffff888096994090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900019932e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/9457: #0: ffff888097c82090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900019132e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 2 locks held by getty/9458: #0: ffff88809f646090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:267 #1: ffffc900018e32e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.3/20813: #0: ffff8880a3aad070 (&fb_info->lock){+.+.}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a3aad070 (&fb_info->lock){+.+.}, at: fb_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1447 1 lock held by syz-executor.0/20818: #0: ffff8880a3aad070 (&fb_info->lock){+.+.}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a3aad070 (&fb_info->lock){+.+.}, at: fb_release+0x4e/0x140 drivers/video/fbdev/core/fbmem.c:1447 2 locks held by syz-executor.5/20833: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1134 Comm: khungtaskd Not tainted 5.6.0-rc3-next-20200228-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:147 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:249 [inline] watchdog+0xde3/0x14e0 kernel/hung_task.c:333 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: 20833 Comm: syz-executor.5 Not tainted 5.6.0-rc3-next-20200228-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:153 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x9/0x50 kernel/kcov.c:187 Code: cc 65 48 8b 04 25 c0 1e 02 00 48 8b 80 a0 13 00 00 c3 0f 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00 65 48 8b 04 25 c0 1e 02 00 <65> 8b 15 f8 88 8f 7e 81 e2 00 01 1f 00 48 8b 34 24 75 2b 8b 90 88 RSP: 0018:ffffc90001cf7470 EFLAGS: 00000202 RAX: ffff88804c42e640 RBX: 0000000000000000 RCX: ffffffff83b3d904 RDX: 0000000000000008 RSI: 0000000000000007 RDI: 0000000000000005 RBP: ffff8880000a0100 R08: ffff88804c42e640 R09: 0000000000000040 R10: ffffed1014761873 R11: ffff8880a3b0c39f R12: 0000000000000028 R13: ffff8880000a0000 R14: 0000000000000000 R15: 0000000000000008 FS: 00007f39c6787700(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f77b256c000 CR3: 0000000093f7c000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: bitfill_aligned drivers/video/fbdev/core/cfbfillrect.c:64 [inline] bitfill_aligned+0xfc/0x200 drivers/video/fbdev/core/cfbfillrect.c:35 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:1378 fbcon_switch+0xd1b/0x1740 drivers/video/fbdev/core/fbcon.c:2360 redraw_screen+0x2a8/0x770 drivers/tty/vt/vt.c:1009 fbcon_modechanged+0x5bd/0x780 drivers/video/fbdev/core/fbcon.c:2997 fbcon_set_all_vcs+0x3ad/0x460 drivers/video/fbdev/core/fbcon.c:3035 fbcon_update_vcs+0x26/0x50 drivers/video/fbdev/core/fbcon.c:3042 fb_set_var+0xad0/0xd40 drivers/video/fbdev/core/fbmem.c:1056 do_fb_ioctl+0x390/0x6e0 drivers/video/fbdev/core/fbmem.c:1109 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1185 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x11a/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770 do_syscall_64+0xf6/0x790 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c679 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:00007f39c6786c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f39c67876d4 RCX: 000000000045c679 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000005 RBP: 000000000076bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002ef R14: 00000000004c52b3 R15: 000000000076bfac