==================================================================
BUG: KASAN: global-out-of-bounds in __fb_pad_aligned_buffer include/linux/fb.h:663 [inline]
BUG: KASAN: global-out-of-bounds in fb_pad_aligned_buffer+0xfc/0x120 drivers/video/fbdev/core/fbmem.c:122
Read of size 1 at addr ffffffff86c6895c by task syz-executor.0/17378

CPU: 1 PID: 17378 Comm: syz-executor.0 Not tainted 4.14.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x283 lib/dump_stack.c:58
 print_address_description.cold+0x5/0x1dc mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0xa9/0x2b9 mm/kasan/report.c:393
 __fb_pad_aligned_buffer include/linux/fb.h:663 [inline]
 fb_pad_aligned_buffer+0xfc/0x120 drivers/video/fbdev/core/fbmem.c:122
 bit_putcs_aligned drivers/video/fbdev/core/bitblit.c:99 [inline]
 bit_putcs+0x907/0xc00 drivers/video/fbdev/core/bitblit.c:185
 fbcon_putcs+0x3bb/0x480 drivers/video/fbdev/core/fbcon.c:1301
 do_update_region+0x34b/0x5b0 drivers/tty/vt/vt.c:373
 redraw_screen+0x562/0x760 drivers/tty/vt/vt.c:705
 fbcon_do_set_font+0x6bd/0x990 drivers/video/fbdev/core/fbcon.c:2564
 fbcon_copy_font+0x125/0x190 drivers/video/fbdev/core/fbcon.c:2579
 con_font_copy drivers/tty/vt/vt.c:4238 [inline]
 con_font_op+0x58b/0xf70 drivers/tty/vt/vt.c:4253
 vt_ioctl+0x1376/0x1f20 drivers/tty/vt/vt_ioctl.c:980
 tty_ioctl+0x6c9/0x1220 drivers/tty/tty_io.c:2661
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45c1d9
RSP: 002b:00007f32938b7c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000000e4c0 RCX: 000000000045c1d9
RDX: 0000000020000500 RSI: 0000000000004b72 RDI: 0000000000000003
RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c
R13: 00007fff41e9814f R14: 00007f32938b89c0 R15: 000000000078bf0c

The buggy address belongs to the variable:
 fontdata_8x16+0x10bc/0x1120

Memory state around the buggy address:
 ffffffff86c68800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffffff86c68880: 00 00 00 00 fa fa fa fa 06 fa fa fa fa fa fa fa
>ffffffff86c68900: 05 fa fa fa fa fa fa fa 06 fa fa fa fa fa fa fa
                                                    ^
 ffffffff86c68980: 00 00 03 fa fa fa fa fa 00 00 00 00 00 00 00 00
 ffffffff86c68a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================