==================================================================
BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:372 [inline]
BUG: KASAN: slab-out-of-bounds in fbcon_get_font+0x2b8/0x660 drivers/video/fbdev/core/fbcon.c:2424
Read of size 32 at addr ffff88809013dd90 by task syz-executor.0/29509

CPU: 0 PID: 29509 Comm: syz-executor.0 Not tainted 4.14.192-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+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x194 mm/kasan/report.c:351
 kasan_report+0x6f/0x7b mm/kasan/report.c:409
 memcpy+0x20/0x50 mm/kasan/kasan.c:302
 memcpy include/linux/string.h:372 [inline]
 fbcon_get_font+0x2b8/0x660 drivers/video/fbdev/core/fbcon.c:2424
 con_font_get drivers/tty/vt/vt.c:4105 [inline]
 con_font_op+0x1c6/0xf60 drivers/tty/vt/vt.c:4256
 vt_ioctl+0x127b/0x1ea0 drivers/tty/vt/vt_ioctl.c:980
 tty_ioctl+0x50f/0x13c0 drivers/tty/tty_io.c:2661
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xff0 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: 0033:0x45ccd9
RSP: 002b:00007f09b6809c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000000f5c0 RCX: 000000000045ccd9
RDX: 0000000020000000 RSI: 0000000000004b72 RDI: 0000000000000005
RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c
R13: 00007ffd770349df R14: 00007f09b680a9c0 R15: 000000000078bf0c

Allocated by task 13552:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
 __do_kmalloc mm/slab.c:3720 [inline]
 __kmalloc+0x15a/0x400 mm/slab.c:3729
 kmalloc include/linux/slab.h:493 [inline]
 fbcon_set_font+0x2fb/0x7c0 drivers/video/fbdev/core/fbcon.c:2621
 con_font_set drivers/tty/vt/vt.c:4189 [inline]
 con_font_op+0xb69/0xf60 drivers/tty/vt/vt.c:4254
 vt_ioctl+0xd91/0x1ea0 drivers/tty/vt/vt_ioctl.c:928
 tty_ioctl+0x50f/0x13c0 drivers/tty/tty_io.c:2661
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xff0 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

Freed by task 12544:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xc9/0x250 mm/slab.c:3815
 con_font_set drivers/tty/vt/vt.c:4193 [inline]
 con_font_op+0xb80/0xf60 drivers/tty/vt/vt.c:4254
 vt_ioctl+0xd91/0x1ea0 drivers/tty/vt/vt_ioctl.c:928
 tty_ioctl+0x50f/0x13c0 drivers/tty/tty_io.c:2661
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xff0 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

The buggy address belongs to the object at ffff88809013c480
 which belongs to the cache kmalloc-8192 of size 8192
The buggy address is located 6416 bytes inside of
 8192-byte region [ffff88809013c480, ffff88809013e480)
The buggy address belongs to the page:
page:ffffea0002404f00 count:1 mapcount:0 mapping:ffff88809013c480 index:0x0 compound_mapcount: 0
flags: 0xfffe0000008100(slab|head)
raw: 00fffe0000008100 ffff88809013c480 0000000000000000 0000000100000001
raw: ffffea00025a1320 ffffea0002287320 ffff88812fe51080 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809013dc80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88809013dd00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88809013dd80: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                         ^
 ffff88809013de00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88809013de80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================