INFO: task syz-executor.1:9967 blocked for more than 143 seconds. Not tainted 5.7.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D27296 9967 7170 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4163 schedule_timeout+0x55b/0x850 kernel/time/timer.c:1874 __down_common kernel/locking/semaphore.c:220 [inline] __down+0x176/0x2c0 kernel/locking/semaphore.c:237 down+0x57/0x80 kernel/locking/semaphore.c:61 console_lock+0x25/0x80 kernel/printk/printk.c:2314 vcs_open+0x62/0xc0 drivers/tty/vt/vc_screen.c:688 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x4ba/0x1290 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x1e59/0x27d0 fs/namei.c:3346 do_filp_open+0x192/0x260 fs/namei.c:3373 do_sys_openat2+0x585/0x7d0 fs/open.c:1148 do_sys_open+0xc3/0x140 fs/open.c:1164 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x416661 Code: 24 10 48 c7 44 24 18 02 00 00 00 e8 49 02 00 00 48 8b 44 24 20 48 89 c1 48 c1 e0 03 48 8b 94 24 80 00 00 00 48 39 d0 75 75 48 <89> c8 e9 67 ff ff ff 48 89 f0 b9 28 00 00 00 e8 fb 8f 04 00 48 89 RSP: 002b:00007f77ea7707a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 6666666666666667 RCX: 0000000000416661 RDX: 0000000000000000 RSI: 0000000000101000 RDI: 00007f77ea770850 RBP: 000000000076bfa0 R08: 000000000000000f R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00000000ffffffff R13: 0000000000000c15 R14: 00000000004ce483 R15: 000000000076bfac INFO: task syz-executor.1:9970 blocked for more than 143 seconds. Not tainted 5.7.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D27496 9970 7170 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4163 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4222 __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_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x4ba/0x1290 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x1e59/0x27d0 fs/namei.c:3346 do_filp_open+0x192/0x260 fs/namei.c:3373 do_sys_openat2+0x585/0x7d0 fs/open.c:1148 do_sys_open+0xc3/0x140 fs/open.c:1164 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45c869 Code: 04 24 48 89 4c 24 08 48 89 54 24 10 e8 d0 5c fa ff 80 7c 24 18 00 74 cf 48 8b 44 24 38 48 8b 48 60 48 85 c9 74 1a 8b 54 24 24 <85> d2 74 12 8b 5c 24 68 0f b7 0c 59 81 e1 ff 7f 00 00 39 d1 75 30 RSP: 002b:00007f77ea74fc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f77ea7506d4 RCX: 000000000045c869 RDX: 0000000000000000 RSI: 0000000020000180 RDI: ffffffffffffff9c RBP: 000000000076c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000079a R14: 00000000004ca55c R15: 000000000076c04c INFO: task syz-executor.1:10007 blocked for more than 143 seconds. Not tainted 5.7.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28400 10007 7170 0x00000004 Call Trace: schedule+0xd0/0x2a0 kernel/sched/core.c:4163 schedule_timeout+0x55b/0x850 kernel/time/timer.c:1874 __down_common kernel/locking/semaphore.c:220 [inline] __down+0x176/0x2c0 kernel/locking/semaphore.c:237 down+0x57/0x80 kernel/locking/semaphore.c:61 console_lock+0x25/0x80 kernel/printk/printk.c:2314 vcs_open+0x62/0xc0 drivers/tty/vt/vc_screen.c:688 chrdev_open+0x219/0x5c0 fs/char_dev.c:414 do_dentry_open+0x4ba/0x1290 fs/open.c:797 do_open fs/namei.c:3229 [inline] path_openat+0x1e59/0x27d0 fs/namei.c:3346 do_filp_open+0x192/0x260 fs/namei.c:3373 do_sys_openat2+0x585/0x7d0 fs/open.c:1148 do_sys_open+0xc3/0x140 fs/open.c:1164 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x416661 Code: 24 10 48 c7 44 24 18 02 00 00 00 e8 49 02 00 00 48 8b 44 24 20 48 89 c1 48 c1 e0 03 48 8b 94 24 80 00 00 00 48 39 d0 75 75 48 <89> c8 e9 67 ff ff ff 48 89 f0 b9 28 00 00 00 e8 fb 8f 04 00 48 89 RSP: 002b:00007f77ea70d7a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 6666666666666667 RCX: 0000000000416661 RDX: 0000000000000000 RSI: 0000000000101000 RDI: 00007f77ea70d850 RBP: 000000000076c180 R08: 000000000000000f R09: 0000000000000000 R10: 00007f77ea70e9d0 R11: 0000000000000293 R12: 00000000ffffffff R13: 0000000000000c15 R14: 00000000004ce483 R15: 000000000076c18c Showing all locks held in the system: 1 lock held by khungtaskd/1140: #0: ffffffff899bed00 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5754 1 lock held by in:imklog/6702: #0: ffff8880a90ef0f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:826 2 locks held by syz-executor.1/9963: 1 lock held by syz-executor.1/9970: #0: ffff888218eb7078 (&fb_info->lock){+.+.}-{3:3}, at: lock_fb_info include/linux/fb.h:637 [inline] #0: ffff888218eb7078 (&fb_info->lock){+.+.}-{3:3}, at: fb_open+0xd3/0x430 drivers/video/fbdev/core/fbmem.c:1418 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1140 Comm: khungtaskd Not tainted 5.7.0-rc1-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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xa8c/0x1010 kernel/hung_task.c:289 kthread+0x388/0x470 kernel/kthread.c:268 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: 9963 Comm: syz-executor.1 Not tainted 5.7.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:write_comp_data+0x1e/0x70 kernel/kcov.c:208 Code: 48 89 11 c3 0f 1f 84 00 00 00 00 00 65 4c 8b 04 25 00 1f 02 00 65 8b 05 68 ea 8e 7e a9 00 01 1f 00 75 51 41 8b 80 d8 13 00 00 <83> f8 03 75 45 49 8b 80 e0 13 00 00 45 8b 80 dc 13 00 00 4c 8b 08 RSP: 0018:ffffc9001606f590 EFLAGS: 00000246 RAX: 0000000000000002 RBX: 0000000000000050 RCX: ffffffff83c364ea RDX: 000000000000003e RSI: 0000000000000050 RDI: 0000000000000004 RBP: 000000000000003e R08: ffff88805043c480 R09: ffffed10431c9dec R10: ffff888218e4ef5f R11: ffffed10431c9deb R12: ffff8880000a003e R13: ffff8880000a0000 R14: 0000000000000000 R15: 00000000f0bb4ad1 FS: 00007f77ea792700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fce82f67000 CR3: 0000000096c52000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vga16fb_fillrect+0x9da/0x1960 drivers/video/fbdev/vga16fb.c:922 bit_clear_margins+0x2d5/0x4a0 drivers/video/fbdev/core/bitblit.c:232 fbcon_clear_margins+0x1de/0x240 drivers/video/fbdev/core/fbcon.c:1381 fbcon_switch+0xd21/0x1740 drivers/video/fbdev/core/fbcon.c:2363 redraw_screen+0x2ae/0x770 drivers/tty/vt/vt.c:1009 fbcon_modechanged+0x5c3/0x790 drivers/video/fbdev/core/fbcon.c:3000 fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:3047 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+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45c869 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:00007f77ea791c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f77ea7926d4 RCX: 000000000045c869 RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000007 RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000002f0 R14: 00000000004c5524 R15: 000000000076bf0c