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BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:347 [inline]
BUG: KASAN: slab-out-of-bounds in fbcon_get_font+0x262/0x530 drivers/video/fbdev/core/fbcon.c:2424
Read of size 8 at addr ffff88805c6cce50 by task syz-executor.5/15471

CPU: 1 PID: 15471 Comm: syz-executor.5 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+0x54/0x1dc 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
 memcpy+0x20/0x50 mm/kasan/kasan.c:302
 memcpy include/linux/string.h:347 [inline]
 fbcon_get_font+0x262/0x530 drivers/video/fbdev/core/fbcon.c:2424
 con_font_get drivers/tty/vt/vt.c:4098 [inline]
 con_font_op+0x1c6/0xf70 drivers/tty/vt/vt.c:4249
 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: 0033:0x45cba9
RSP: 002b:00007fad9659dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004e7d00 RCX: 000000000045cba9
RDX: 0000000020000400 RSI: 0000000000004b72 RDI: 0000000000000003
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000380 R14: 00000000004c62b2 R15: 00007fad9659e6d4

Allocated by task 12854:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc.part.0+0x4f/0xd0 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+0x2f8/0x7c0 drivers/video/fbdev/core/fbcon.c:2621
 con_font_set drivers/tty/vt/vt.c:4182 [inline]
 con_font_op+0xb73/0xf70 drivers/tty/vt/vt.c:4247
 vt_ioctl+0x736/0x1f20 drivers/tty/vt/vt_ioctl.c:928
 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

Freed by task 0:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xaf/0x190 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xcb/0x260 mm/slab.c:3815
 __rcu_reclaim kernel/rcu/rcu.h:190 [inline]
 rcu_do_batch kernel/rcu/tree.c:2699 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2962 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2929 [inline]
 rcu_process_callbacks+0x89e/0x1180 kernel/rcu/tree.c:2946
 __do_softirq+0x254/0x9bf kernel/softirq.c:288

The buggy address belongs to the object at ffff88805c6cc940
 which belongs to the cache kmalloc-2048 of size 2048
The buggy address is located 1296 bytes inside of
 2048-byte region [ffff88805c6cc940, ffff88805c6cd140)
The buggy address belongs to the page:
page:ffffea000171b300 count:1 mapcount:0 mapping:ffff88805c6cc0c0 index:0x0 compound_mapcount: 0
flags: 0xfffe0000008100(slab|head)
raw: 00fffe0000008100 ffff88805c6cc0c0 0000000000000000 0000000100000003
raw: ffffea000171b4a0 ffffea000171c220 ffff8880aa800c40 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88805c6ccd00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805c6ccd80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88805c6cce00: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
                                                 ^
 ffff88805c6cce80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88805c6ccf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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