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BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:425 [inline]
BUG: KASAN: slab-out-of-bounds in fbcon_get_font+0x2b2/0x5e0 drivers/video/fbdev/core/fbcon.c:2465
Read of size 5 at addr ffff8880a83f440c by task syz-executor898/9345

CPU: 0 PID: 9345 Comm: syz-executor898 Not tainted 5.5.0-rc2-next-20191220-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+0x197/0x210 lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374
 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:639
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x134/0x1a0 mm/kasan/generic.c:192
 memcpy+0x24/0x50 mm/kasan/common.c:125
 memcpy include/linux/string.h:425 [inline]
 fbcon_get_font+0x2b2/0x5e0 drivers/video/fbdev/core/fbcon.c:2465
 con_font_get drivers/tty/vt/vt.c:4446 [inline]
 con_font_op+0x20b/0x1270 drivers/tty/vt/vt.c:4605
 vt_ioctl+0xd2e/0x26d0 drivers/tty/vt/vt_ioctl.c:913
 tty_ioctl+0xa37/0x14f0 drivers/tty/tty_io.c:2660
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x123/0x180 fs/ioctl.c:747
 __do_sys_ioctl fs/ioctl.c:756 [inline]
 __se_sys_ioctl fs/ioctl.c:754 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x448a09
Code: e8 1c e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 8b 06 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ff8b0880ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000006e49e8 RCX: 0000000000448a09
RDX: 0000000020000140 RSI: 0000000000004b60 RDI: 0000000000000003
RBP: 00000000006e49e0 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000000e R11: 0000000000000246 R12: 00000000006e49ec
R13: 00007ffd4fecc4bf R14: 00007ff8b08819c0 R15: 20c49ba5e353f7cf

Allocated by task 9333:
 save_stack+0x23/0x90 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 __kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:486
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:527
 __do_kmalloc mm/slab.c:3656 [inline]
 __kmalloc+0x163/0x770 mm/slab.c:3665
 kmalloc include/linux/slab.h:560 [inline]
 fbcon_set_font+0x32d/0x860 drivers/video/fbdev/core/fbcon.c:2663
 con_font_set drivers/tty/vt/vt.c:4538 [inline]
 con_font_op+0xe30/0x1270 drivers/tty/vt/vt.c:4603
 vt_ioctl+0xd2e/0x26d0 drivers/tty/vt/vt_ioctl.c:913
 tty_ioctl+0xa37/0x14f0 drivers/tty/tty_io.c:2660
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x123/0x180 fs/ioctl.c:747
 __do_sys_ioctl fs/ioctl.c:756 [inline]
 __se_sys_ioctl fs/ioctl.c:754 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8880a83f4000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1036 bytes inside of
 2048-byte region [ffff8880a83f4000, ffff8880a83f4800)
The buggy address belongs to the page:
page:ffffea0002a0fd00 refcount:1 mapcount:0 mapping:ffff8880aa400e00 index:0x0
raw: 00fffe0000000200 ffffea00028fd448 ffffea0002818c88 ffff8880aa400e00
raw: 0000000000000000 ffff8880a83f4000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a83f4300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880a83f4380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880a83f4400: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                         ^
 ffff8880a83f4480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a83f4500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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