general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 10527 Comm: syz-executor.5 Not tainted 5.8.0-rc3-next-20200703-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__switch_to_asm+0x0/0x40 arch/x86/entry/entry_64.S:229
Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
RSP: 0018:ffffc9000cadf3d8 EFLAGS: 00010046
RAX: dffffc0000000000 RBX: ffff8880ae735e18 RCX: 0000000000000000
RDX: 1ffff11015ce6bc2 RSI: ffff888060dfa3c0 RDI: ffff88804ed0e1c0
RBP: ffffc9000cadf4a8 R08: 0000000000000001 R09: ffff88804ed0ea90
R10: fffffbfff155e051 R11: 0000000000000000 R12: ffff8880ae735e00
R13: ffff88804ed0e1c0 R14: ffff888060dfa3c0 R15: ffff88804ed0e5f0
FS:  00007fb2b4506700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004ea4f0 CR3: 0000000060dd1000 CR4: 00000000001526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 context_switch kernel/sched/core.c:3445 [inline]
 __schedule+0x8b4/0x1e80 kernel/sched/core.c:4169
 preempt_schedule_irq+0xb0/0x150 kernel/sched/core.c:4427
 idtentry_exit_cond_resched arch/x86/entry/common.c:645 [inline]
 idtentry_exit_cond_rcu+0xc0/0xf0 arch/x86/entry/common.c:692
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:596
RIP: 0010:write_comp_data+0x78/0x80 kernel/kcov.c:242
Code: 00 00 4e 8d 0c dd 28 00 00 00 4c 39 ce 72 1b 49 83 c0 01 4a 89 7c 08 e0 4e 89 54 08 e8 4a 89 54 08 f0 4a 89 4c d8 20 4c 89 00 <c3> 0f 1f 80 00 00 00 00 48 8b 0c 24 40 0f b6 d6 40 0f b6 f7 31 ff
RSP: 0018:ffffc9000cadf5a8 EFLAGS: 00000297
RAX: 0000000000000002 RBX: 000000001fffffb0 RCX: ffffffff83c84e94
RDX: 0000000000f691d1 RSI: ffff88804ed0e1c0 RDI: 0000000000000004
RBP: 0000000000f691d1 R08: 0000000000000001 R09: ffff88821886931f
R10: 000000001fffffb0 R11: 0000000000000000 R12: ffff888001009221
R13: ffff8880000a0050 R14: 0000000000000000 R15: 00000000000002a9
 vga16fb_fillrect+0x9d4/0x193b drivers/video/fbdev/vga16fb.c:922
 bit_clear_margins+0x3f6/0x4a0 drivers/video/fbdev/core/bitblit.c:224
 fbcon_clear_margins+0x1d5/0x230 drivers/video/fbdev/core/fbcon.c:1381
 fbcon_switch+0xb6f/0x16c0 drivers/video/fbdev/core/fbcon.c:2363
 redraw_screen+0x2af/0x770 drivers/tty/vt/vt.c:1020
 fbcon_modechanged+0x575/0x710 drivers/video/fbdev/core/fbcon.c:3001
 fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:3048
 fb_set_var+0xae8/0xd60 drivers/video/fbdev/core/fbmem.c:1056
 do_fb_ioctl+0x33f/0x6c0 drivers/video/fbdev/core/fbmem.c:1109
 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1185
 vfs_ioctl fs/ioctl.c:48 [inline]
 ksys_ioctl+0x11a/0x180 fs/ioctl.c:753
 __do_sys_ioctl fs/ioctl.c:762 [inline]
 __se_sys_ioctl fs/ioctl.c:760 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:367
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45cb29
Code: Bad RIP value.
RSP: 002b:00007fb2b4505c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004e55e0 RCX: 000000000045cb29
RDX: 0000000020000000 RSI: 0000000000004601 RDI: 0000000000000003
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000002fd R14: 00000000004c58a5 R15: 00007fb2b45066d4
Modules linked in:
---[ end trace ce89526e689769df ]---
RIP: 0010:__switch_to_asm+0x0/0x40 arch/x86/entry/entry_64.S:229
Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
RSP: 0018:ffffc9000cadf3d8 EFLAGS: 00010046
RAX: dffffc0000000000 RBX: ffff8880ae735e18 RCX: 0000000000000000
RDX: 1ffff11015ce6bc2 RSI: ffff888060dfa3c0 RDI: ffff88804ed0e1c0
RBP: ffffc9000cadf4a8 R08: 0000000000000001 R09: ffff88804ed0ea90
R10: fffffbfff155e051 R11: 0000000000000000 R12: ffff8880ae735e00
R13: ffff88804ed0e1c0 R14: ffff888060dfa3c0 R15: ffff88804ed0e5f0
FS:  00007fb2b4506700(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004ea4f0 CR3: 0000000060dd1000 CR4: 00000000001526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400