FYI, we noticed the following commit: commit: 903a69cad7ac6cc504c81d7605be1053ba264466 ("fbcon: add VT notifier for VT_UPDATE event") url: https://github.com/0day-ci/linux/commits/David-Lechner/fbcon-Invert-margin-colors-when-terminal-is-inverted/20170801-082646 in testcase: trinity with following parameters: runtime: 300s test-description: Trinity is a linux system call fuzz tester. test-url: http://codemonkey.org.uk/projects/trinity/ on test machine: qemu-system-x86_64 -enable-kvm -m 512M caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +------------------------------------------+------------+------------+ | | c494f471e2 | 903a69cad7 | +------------------------------------------+------------+------------+ | boot_successes | 4 | 0 | | boot_failures | 4 | 22 | | BUG:kernel_hang_in_test_stage | 4 | 4 | | BUG:unable_to_handle_kernel | 0 | 22 | | Oops:#[##] | 0 | 22 | | Kernel_panic-not_syncing:Fatal_exception | 0 | 22 | | BUG:kernel_in_stage | 0 | 2 | +------------------------------------------+------------+------------+ [ 0.199700] BUG: unable to handle kernel NULL pointer dereference at 0000000000000348 [ 0.199701] IP: fbcon_clear_margins+0x1c/0x80 [ 0.199701] PGD 0 P4D 0 [ 0.199702] Oops: 0000 [#1] SMP [ 0.199702] Modules linked in: [ 0.199702] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.13.0-rc2-00024-g903a69ca #3 [ 0.199703] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-20161025_171302-gandalf 04/01/2014 [ 0.199703] task: ffff880011630000 task.stack: ffffc900000d0000 [ 0.199703] RIP: 0010:fbcon_clear_margins+0x1c/0x80 [ 0.199703] RSP: 0000:ffffc900000d3c30 EFLAGS: 00010046 [ 0.199704] RAX: 0000000000000000 RBX: 00000000ffffffff RCX: 00000000ffffffff [ 0.199704] RDX: ffffc900000d3ca8 RSI: 0000000000000000 RDI: ffff880011434800 [ 0.199705] RBP: ffffc900000d3c38 R08: 0000000000000000 R09: ffffffff81f95fc0 [ 0.199705] R10: ffff8800000ba3a0 R11: 000000008238a601 R12: 0000000000000000 [ 0.199705] R13: 0000000000000004 R14: ffffc900000d3ca8 R15: 0000000000000000 [ 0.199705] FS: 0000000000000000(0000) GS:ffff88001e000000(0000) knlGS:0000000000000000 [ 0.199706] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.199706] CR2: 0000000000000348 CR3: 0000000001e09000 CR4: 00000000000006f0 [ 0.199706] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 0.199707] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 0.199707] Call Trace: [ 0.199707] ? vt_notifier_call+0x34/0x40 [ 0.199707] notifier_call_chain+0x4a/0x70 [ 0.199707] atomic_notifier_call_chain+0x21/0x30 [ 0.199708] vt_console_print+0x219/0x3c0 [ 0.199708] console_unlock+0x3f9/0x4f0 [ 0.199708] vprintk_emit+0x302/0x3b0 [ 0.199708] ? pnpacpi_add_device_handler+0x23b/0x23b [ 0.199708] ? set_debug_rodata+0x17/0x17 [ 0.199709] vprintk_default+0x1f/0x30 [ 0.199709] vprintk_func+0x27/0x60 [ 0.199709] printk+0x43/0x4b [ 0.199709] ? kobject_uevent+0xb/0x10 [ 0.199710] ? kobject_uevent_env+0x153/0x690 [ 0.199710] pnpacpi_init+0x35/0x73 [ 0.199710] do_one_initcall+0x43/0x170 [ 0.199710] ? set_debug_rodata+0x17/0x17 [ 0.199710] kernel_init_freeable+0x198/0x220 [ 0.199711] ? rest_init+0xe0/0xe0 [ 0.199711] kernel_init+0xe/0x101 [ 0.199711] ret_from_fork+0x25/0x30 [ 0.199711] Code: ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 0f b7 87 60 01 00 00 48 0f be 80 60 19 4d 82 48 8b 04 c5 20 78 0a 82 <44> 8b 90 48 03 00 00 48 8b 88 50 03 00 00 45 85 d2 75 09 80 bf [ 0.199717] RIP: fbcon_clear_margins+0x1c/0x80 RSP: ffffc900000d3c30 [ 0.199718] CR2: 0000000000000348 [ 0.199721] ---[ end trace f2e7a2a7be17dc74 ]--- To reproduce: git clone https://github.com/01org/lkp-tests.git cd lkp-tests bin/lkp qemu -k job-script # job-script is attached in this email Thanks, Xiaolong