kobject: 'bridge0' (000000003a1c2e5d): calling ktype release kobject: 'bridge0': free name kobject: 'lo' (0000000031f8b270): kobject_cleanup, parent (null) kobject: 'lo' (0000000031f8b270): calling ktype release kobject: 'lo': free name INFO: task syz-executor.0:25809 blocked for more than 140 seconds. Not tainted 4.19.91-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28304 25809 25520 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3515 schedule+0x92/0x1c0 kernel/sched/core.c:3559 schedule_timeout+0x8c8/0xfc0 kernel/time/timer.c:1782 __down_common kernel/locking/semaphore.c:221 [inline] __down+0x176/0x2c0 kernel/locking/semaphore.c:238 down+0x64/0x90 kernel/locking/semaphore.c:62 console_lock+0x29/0x80 kernel/printk/printk.c:2244 vcs_open+0x67/0xd0 drivers/tty/vt/vc_screen.c:660 chrdev_open+0x245/0x6b0 fs/char_dev.c:423 do_dentry_open+0x4c3/0x1210 fs/open.c:796 vfs_open+0xa0/0xd0 fs/open.c:905 do_last fs/namei.c:3418 [inline] path_openat+0x10d7/0x45e0 fs/namei.c:3534 do_filp_open+0x1a1/0x280 fs/namei.c:3564 do_sys_open+0x3fe/0x550 fs/open.c:1088 __do_sys_open fs/open.c:1106 [inline] __se_sys_open fs/open.c:1101 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1101 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4146b1 Code: ff ff 48 3b 61 10 0f 86 6b 01 00 00 48 83 ec 20 48 89 6c 24 18 48 8d 6c 24 18 48 8b 44 24 30 0f b6 48 63 84 c9 0f 85 31 01 00 <00> c6 40 65 01 0f b6 4c 24 38 84 c9 74 25 48 8b 48 10 48 85 c9 0f RSP: 002b:00007f48395997a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 6666666666666667 RCX: 00000000004146b1 RDX: 0000000000000000 RSI: 0000000000080101 RDI: 00007f4839599850 RBP: 000000000075bfc8 R08: 000000000000000f R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007f483959a6d4 R13: 00000000004cb1fe R14: 00000000004e4930 R15: 00000000ffffffff INFO: task syz-executor.0:25833 blocked for more than 140 seconds. Not tainted 4.19.91-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D29184 25833 25520 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x866/0x1dc0 kernel/sched/core.c:3515 schedule+0x92/0x1c0 kernel/sched/core.c:3559 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3617 __mutex_lock_common kernel/locking/mutex.c:1002 [inline] __mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087 fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1457 chrdev_open+0x245/0x6b0 fs/char_dev.c:423 do_dentry_open+0x4c3/0x1210 fs/open.c:796 vfs_open+0xa0/0xd0 fs/open.c:905 do_last fs/namei.c:3418 [inline] path_openat+0x10d7/0x45e0 fs/namei.c:3534 do_filp_open+0x1a1/0x280 fs/namei.c:3564 do_sys_open+0x3fe/0x550 fs/open.c:1088 __do_sys_openat fs/open.c:1115 [inline] __se_sys_openat fs/open.c:1109 [inline] __x64_sys_openat+0x9d/0x100 fs/open.c:1109 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a919 Code: 8d 0c 1f 48 81 eb 80 00 00 00 0f 18 86 c0 01 00 00 0f 18 86 80 02 00 00 c5 fe 6f 06 c5 fe 6f 4e 20 c5 fe 6f 56 40 c5 fe 6f 5e <60> 48 81 c6 80 00 00 00 c5 fd e7 07 c5 fd e7 4f 20 c5 fd e7 57 40 RSP: 002b:00007f4839578c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045a919 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f48395796d4 R13: 00000000004c8067 R14: 00000000004df338 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1067: #0: 000000008f319d17 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438 1 lock held by rsyslogd/7643: #0: 000000003d459e2b (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767 2 locks held by getty/7767: #0: 0000000074926d9b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000839f9a8b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7768: #0: 000000009bb9d632 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 0000000026e9664b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7769: #0: 00000000e725d80c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000ed067b9f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7770: #0: 00000000c54f84df (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000006e6e02a7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7771: #0: 0000000059628e4e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 00000000684fd838 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/7772: #0: 00000000df39e558 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 000000009757abd6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 2 locks held by getty/9311: #0: 00000000a0178bcb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362 #1: 0000000067f58f39 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154 3 locks held by syz-executor.0/25791: 1 lock held by syz-executor.0/25833: #0: 000000005033757b (&fb_info->lock){+.+.}, at: fb_open+0xd7/0x450 drivers/video/fbdev/core/fbmem.c:1457 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1067 Comm: khungtaskd Not tainted 4.19.91-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+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 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:203 [inline] watchdog+0x9df/0xee0 kernel/hung_task.c:287 kthread+0x354/0x420 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: 25791 Comm: syz-executor.0 Not tainted 4.19.91-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__sanitizer_cov_trace_pc+0x3f/0x50 kernel/kcov.c:107 Code: a9 96 7e 81 e2 00 01 1f 00 75 2b 8b 90 d0 12 00 00 83 fa 02 75 20 48 8b 88 d8 12 00 00 8b 80 d4 12 00 00 48 8b 11 48 83 c2 01 <48> 39 d0 76 07 48 89 34 d1 48 89 11 5d c3 0f 1f 00 65 4c 8b 04 25 RSP: 0018:ffff8880479270f0 EFLAGS: 00000216 RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc9000eddb000 RDX: 0000000000040000 RSI: ffffffff8383a1c6 RDI: 0000000000000005 RBP: ffff8880479270f0 R08: ffff8880350a2600 R09: 0000000000000040 R10: ffffed1014bee44b R11: ffff8880a5f7225f R12: 00000000000000a0 R13: 0000000000000018 R14: ffff8880000a0000 R15: ffff8880000a0440 FS: 00007f48395bb700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000000771ef000 CR4: 00000000001426f0 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+0x106/0x210 drivers/video/fbdev/core/cfbfillrect.c:35 cfb_fillrect+0x423/0x7c0 drivers/video/fbdev/core/cfbfillrect.c:327 vga16fb_fillrect+0x6ce/0x19b0 drivers/video/fbdev/vga16fb.c:951 bit_clear_margins+0x30b/0x530 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins+0x2e3/0x370 drivers/video/fbdev/core/fbcon.c:1339 fbcon_switch+0xe7d/0x1a40 drivers/video/fbdev/core/fbcon.c:2321 redraw_screen+0x37d/0x8e0 drivers/tty/vt/vt.c:997 fbcon_modechanged+0x5f3/0x900 drivers/video/fbdev/core/fbcon.c:2969 fbcon_set_all_vcs+0x3d0/0x490 drivers/video/fbdev/core/fbcon.c:3007 fbcon_event_notify+0x9b/0x1dba drivers/video/fbdev/core/fbcon.c:3347 notifier_call_chain+0xc2/0x230 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+0x94/0xb0 kernel/notifier.c:325 fb_notifier_call_chain+0x25/0x30 drivers/video/fbdev/core/fb_notify.c:45 fb_set_var+0xc8f/0xe80 drivers/video/fbdev/core/fbmem.c:1042 do_fb_ioctl+0x450/0xab0 drivers/video/fbdev/core/fbmem.c:1115 fb_ioctl+0xe6/0x130 drivers/video/fbdev/core/fbmem.c:1230 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a919 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:00007f48395bac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a919 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 000000000000000a RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f48395bb6d4 R13: 00000000004c310d R14: 00000000004d8498 R15: 00000000ffffffff