INFO: task syz-executor.0:26626 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.0 D28576 26626 7039 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:3247 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/1141: #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/6695: #0: ffff88809f379af0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x25d/0x2f0 fs/file.c:826 1 lock held by syz-executor.4/26622: 2 locks held by syz-executor.0/26626: #0: ffffffff89475378 (tty_mutex){+.+.}-{3:3}, at: tty_open_by_driver drivers/tty/tty_io.c:1947 [inline] #0: ffffffff89475378 (tty_mutex){+.+.}-{3:3}, at: tty_open+0x338/0xca0 drivers/tty/tty_io.c:2031 #1: ffff8880927671c0 (&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: 1141 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: 26622 Comm: syz-executor.4 Not tainted 5.7.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:vga16fb_fillrect+0xfd4/0x13e0 drivers/video/fbdev/vga16fb.c:922 Code: b2 c9 a1 fd 49 ff c5 45 85 e4 74 38 4d 01 f5 e8 a2 c9 a1 fd 41 ff cc 83 7c 24 18 00 74 1c 44 89 fd 0f 1f 44 00 00 41 88 5d 00 <85> ed 74 d1 49 ff c5 e8 80 c9 a1 fd ff cd eb ec e8 77 c9 a1 fd 45 RSP: 0018:ffffc90006e6f848 EFLAGS: 00000206 RAX: ffffffff83d1a830 RBX: 0000000000000000 RCX: 0000000000040000 RDX: ffffc90012090000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: 000000000000002d R08: ffffffff83d1a7eb R09: ffffffff83d19f5f R10: ffff8880a4040080 R11: 0000000000000002 R12: 00000000dc218571 R13: ffff8880000a0022 R14: ffffffffffffffb0 R15: 000000000000004f FS: 00007f77ca9f8700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c0001f3c80 CR3: 00000000a43f0000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: bit_clear_margins+0x37b/0x620 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins drivers/video/fbdev/core/fbcon.c:1381 [inline] fbcon_do_set_font+0xce2/0x1220 drivers/video/fbdev/core/fbcon.c:2613 fbcon_set_font+0x782/0x970 drivers/video/fbdev/core/fbcon.c:2705 fbcon_blank+0x930/0x930 drivers/video/fbdev/core/fbcon.c:2390 con_font_set drivers/tty/vt/vt.c:4566 [inline] con_font_op+0xebc/0x1630 drivers/tty/vt/vt.c:4631 save_stack mm/kasan/common.c:49 [inline] set_track mm/kasan/common.c:57 [inline] kasan_set_free_info mm/kasan/common.c:317 [inline] __kasan_slab_free+0x125/0x190 mm/kasan/common.c:456 vt_ioctl+0x179d/0x3eb0 drivers/tty/vt/vt_ioctl.c:265 rcu_lock_release+0x5/0x20 include/linux/rcupdate.h:212 tomoyo_path_number_perm+0x58f/0x690 security/tomoyo/file.c:739 tty_jobctrl_ioctl+0x1e8/0xc20 drivers/tty/tty_jobctrl.c:539 tty_ioctl+0xee4/0x15c0 drivers/tty/tty_io.c:2656 tty_do_resize+0x180/0x180 drivers/tty/tty_io.c:2248 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:00007f77ca9f7c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e6920 RCX: 000000000045c829 RDX: 0000000020000000 RSI: 0000000000004b61 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000375 R14: 00000000004c5e6f R15: 00007f77ca9f86d4