INFO: task kworker/0:16:18624 blocked for more than 143 seconds. Not tainted 5.7.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/0:16 D28832 18624 2 0x80004000 Workqueue: events console_callback Call Trace: context_switch kernel/sched/core.c:3367 [inline] __schedule+0x805/0xc90 kernel/sched/core.c:4083 schedule+0x188/0x220 kernel/sched/core.c:4158 schedule_timeout+0x43/0x250 kernel/time/timer.c:1874 mark_held_locks kernel/locking/lockdep.c:3628 [inline] __trace_hardirqs_on_caller kernel/locking/lockdep.c:3657 [inline] lockdep_hardirqs_on+0x4a4/0x8a0 kernel/locking/lockdep.c:3702 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199 __down_common+0x28a/0x520 kernel/locking/semaphore.c:220 down+0x65/0xa0 kernel/locking/semaphore.c:61 console_lock+0x24/0x70 kernel/printk/printk.c:2314 console_callback+0x2c/0x330 drivers/tty/vt/vt.c:2844 process_one_work+0x76e/0xfd0 kernel/workqueue.c:2268 worker_thread+0xa7f/0x1450 kernel/workqueue.c:2414 kthread+0x353/0x380 kernel/kthread.c:268 rcu_lock_release+0x20/0x20 include/linux/rcupdate.h:213 kthread_blkcg+0xd0/0xd0 kernel/kthread.c:1247 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task syz-executor.1:19206 blocked for more than 143 seconds. Not tainted 5.7.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28472 19206 7201 0x00004004 Call Trace: context_switch kernel/sched/core.c:3367 [inline] __schedule+0x805/0xc90 kernel/sched/core.c:4083 schedule+0x188/0x220 kernel/sched/core.c:4158 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4217 __mutex_lock_common+0x129f/0x2fc0 kernel/locking/mutex.c:1033 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0x14b/0x3b0 drivers/video/fbdev/core/fbmem.c:1418 __mutex_lock kernel/locking/mutex.c:1103 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118 lock_fb_info include/linux/fb.h:637 [inline] fb_open+0x14b/0x3b0 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x498/0x580 fs/char_dev.c:414 cd_forget+0x150/0x150 include/linux/spinlock.h:393 do_dentry_open+0x82e/0x10b0 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x2790/0x38b0 fs/namei.c:3346 check_preemption_disabled+0xa2/0x240 lib/smp_processor_id.c:19 do_filp_open+0x191/0x3a0 fs/namei.c:3373 __raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock+0x24/0x40 kernel/locking/spinlock.c:183 spin_unlock include/linux/spinlock.h:393 [inline] __alloc_fd+0x566/0x600 fs/file.c:534 do_sys_openat2+0x463/0x770 fs/open.c:1148 do_sys_open fs/open.c:1164 [inline] __do_sys_openat fs/open.c:1178 [inline] __se_sys_openat fs/open.c:1173 [inline] __x64_sys_openat+0x1c8/0x1f0 fs/open.c:1173 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 INFO: task syz-executor.3:19180 blocked for more than 143 seconds. Not tainted 5.7.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28560 19180 7391 0x00004004 Call Trace: context_switch kernel/sched/core.c:3367 [inline] __schedule+0x805/0xc90 kernel/sched/core.c:4083 schedule+0x188/0x220 kernel/sched/core.c:4158 schedule_timeout+0x43/0x250 kernel/time/timer.c:1874 mark_held_locks kernel/locking/lockdep.c:3628 [inline] __trace_hardirqs_on_caller kernel/locking/lockdep.c:3657 [inline] lockdep_hardirqs_on+0x4a4/0x8a0 kernel/locking/lockdep.c:3702 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199 __down_common+0x28a/0x520 kernel/locking/semaphore.c:220 down+0x65/0xa0 kernel/locking/semaphore.c:61 console_lock+0x24/0x70 kernel/printk/printk.c:2314 con_install+0x50/0x650 drivers/tty/vt/vt.c:3252 tty_driver_install_tty drivers/tty/tty_io.c:1228 [inline] tty_init_dev+0xc6/0x4c0 drivers/tty/tty_io.c:1341 tty_open_by_driver drivers/tty/tty_io.c:1983 [inline] tty_open+0x7cd/0xca0 drivers/tty/tty_io.c:2031 chrdev_open+0x498/0x580 fs/char_dev.c:414 cd_forget+0x150/0x150 include/linux/spinlock.h:393 do_dentry_open+0x82e/0x10b0 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x2790/0x38b0 fs/namei.c:3346 do_filp_open+0x191/0x3a0 fs/namei.c:3373 __raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock+0x24/0x40 kernel/locking/spinlock.c:183 do_sys_openat2+0x463/0x770 fs/open.c:1148 do_sys_open fs/open.c:1164 [inline] ksys_open include/linux/syscalls.h:1386 [inline] __do_sys_open fs/open.c:1170 [inline] __se_sys_open fs/open.c:1168 [inline] __x64_sys_open+0x1af/0x1e0 fs/open.c:1168 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Showing all locks held in the system: 1 lock held by khungtaskd/1140: #0: ffffffff892e8550 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 net/mptcp/pm_netlink.c:860 1 lock held by in:imklog/6683: #0: ffff8880a28e5930 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x25d/0x2f0 fs/file.c:826 2 locks held by agetty/6733: #0: ffff8880a84cd098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:267 #1: ffffc90000fa42e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x260/0x1bc0 drivers/tty/n_tty.c:2156 2 locks held by kworker/0:16/18624: #0: ffff8880aa426d38 ((wq_completion)events){+.+.}-{0:0}, at: spin_unlock_irq include/linux/spinlock.h:403 [inline] #0: ffff8880aa426d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x6df/0xfd0 kernel/workqueue.c:2241 #1: ffffc90005ea7d80 (console_work){+.+.}-{0:0}, at: process_one_work+0x71e/0xfd0 kernel/workqueue.c:2243 2 locks held by syz-executor.1/19175: 1 lock held by syz-executor.1/19206: #0: ffff8880a341c078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff8880a341c078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0x14b/0x3b0 drivers/video/fbdev/core/fbmem.c:1418 2 locks held by syz-executor.3/19180: #0: ffffffff89475388 (tty_mutex){+.+.}-{3:3}, at: tty_open_by_driver drivers/tty/tty_io.c:1947 [inline] #0: ffffffff89475388 (tty_mutex){+.+.}-{3:3}, at: tty_open+0x338/0xca0 drivers/tty/tty_io.c:2031 #1: ffff88809d63f1c0 (&tty->legacy_mutex){+.+.}-{3:3}, at: tty_init_dev+0x6a/0x4c0 drivers/tty/tty_io.c:1340 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1140 Comm: khungtaskd Not tainted 5.7.0-rc4-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+0x1e9/0x30e lib/dump_stack.c:118 nmi_cpu_backtrace+0x9f/0x180 lib/nmi_backtrace.c:101 arch_trigger_cpumask_backtrace+0x10/0x10 arch/x86/kernel/apic/hw_nmi.c:38 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xd2a/0xd40 kernel/hung_task.c:289 kthread+0x353/0x380 kernel/kthread.c:268 hungtask_pm_notify+0x50/0x50 kernel/hung_task.c:265 kthread_blkcg+0xd0/0xd0 kernel/kthread.c:1247 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: 19175 Comm: syz-executor.1 Not tainted 5.7.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:bitfill_aligned+0x1be/0x1f0 drivers/video/fbdev/core/cfbfillrect.c:78 Code: 33 85 ed 74 0b 48 83 c3 08 e8 3e 14 a6 fd eb ec e8 37 14 a6 fd 48 83 c3 08 eb 05 e8 2c 14 a6 fd 31 ff 44 89 e6 e8 c2 17 a6 fd <45> 85 e4 74 16 e8 18 14 a6 fd 48 8b 03 4c 31 f0 4c 21 f8 4c 31 f0 RSP: 0018:ffffc90008a078f8 EFLAGS: 00000297 RAX: ffff88805889e580 RBX: ffff8880000a0180 RCX: 0000000000000002 RDX: ffffc9000423d000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffff83cd5d8e R09: 0000000000000040 R10: ffff88805889e580 R11: 0000000000000002 R12: 0000000000000000 R13: ffffffffffffffff R14: 0000000000000000 R15: ffffffffffffffff FS: 00007f26f3ff9700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c00741a710 CR3: 000000009f307000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: bitfill_aligned_rev+0x1e0/0x1e0 drivers/video/fbdev/core/cfbfillrect.c:206 cfb_fillrect+0x57b/0x790 drivers/video/fbdev/core/cfbfillrect.c:327 bit_clear_margins+0x37b/0x620 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins drivers/video/fbdev/core/fbcon.c:1381 [inline] fbcon_switch+0x1448/0x1e40 drivers/video/fbdev/core/fbcon.c:2363 redraw_screen+0x4fc/0x16f0 drivers/tty/vt/vt.c:1015 fbcon_modechanged+0x8d5/0xd90 drivers/video/fbdev/core/fbcon.c:3000 fb_set_var+0x822/0xcc0 drivers/video/fbdev/core/fbmem.c:1056 do_fb_ioctl+0x502/0x6f0 drivers/video/fbdev/core/fbmem.c:1109 fb_write+0x540/0x540 drivers/video/fbdev/core/fbmem.c:849 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl fs/ioctl.c:771 [inline] __do_sys_ioctl fs/ioctl.c:780 [inline] __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:778 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45c829 Code: 0d b7 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f26f3ff8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e4860 RCX: 000000000045c829 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000004 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002f2 R14: 00000000004c54c8 R15: 00007f26f3ff96d4