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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:2421
Read of size 3 at addr ffff8880544d294f by task syz-executor.3/19776

CPU: 0 PID: 19776 Comm: syz-executor.3 Not tainted 4.14.172-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+0x13e/0x194 lib/dump_stack.c:58
 print_address_description.cold+0x7c/0x1e2 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+0xa9/0x2ae 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:2421
 con_font_get drivers/tty/vt/vt.c:4078 [inline]
 con_font_op+0x1c6/0xf70 drivers/tty/vt/vt.c:4229
 vt_ioctl+0xaf8/0x1f00 drivers/tty/vt/vt_ioctl.c:918
 tty_ioctl+0x6c5/0x1220 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+0x42/0xb7
RIP: 0033:0x45c479
RSP: 002b:00007f542a018c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f542a0196d4 RCX: 000000000045c479
RDX: 0000000020000000 RSI: 0000000000004b60 RDI: 0000000000000004
RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000586 R14: 00000000004c7dc1 R15: 000000000076bf2c

Allocated by task 16232:
 save_stack+0x32/0xa0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc mm/kasan/kasan.c:551 [inline]
 kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:529
 __do_kmalloc mm/slab.c:3720 [inline]
 __kmalloc+0x15b/0x7c0 mm/slab.c:3729
 kmalloc include/linux/slab.h:493 [inline]
 fbcon_set_font+0x2f8/0x7c0 drivers/video/fbdev/core/fbcon.c:2618
 con_font_set drivers/tty/vt/vt.c:4162 [inline]
 con_font_op+0xb73/0xf70 drivers/tty/vt/vt.c:4227
 vt_ioctl+0xaf8/0x1f00 drivers/tty/vt/vt_ioctl.c:918
 tty_ioctl+0x6c5/0x1220 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+0x42/0xb7

Freed by task 3717:
 save_stack+0x32/0xa0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xcb/0x260 mm/slab.c:3815
 skb_free_head+0x83/0xa0 net/core/skbuff.c:554
 skb_release_data+0x528/0x7b0 net/core/skbuff.c:574
 skb_release_all+0x46/0x60 net/core/skbuff.c:631
 __kfree_skb net/core/skbuff.c:645 [inline]
 consume_skb+0xa7/0x330 net/core/skbuff.c:705
 skb_free_datagram+0x16/0xe0 net/core/datagram.c:331
 unix_dgram_recvmsg+0x70a/0xcd0 net/unix/af_unix.c:2207
 sock_recvmsg_nosec net/socket.c:819 [inline]
 sock_recvmsg net/socket.c:826 [inline]
 sock_recvmsg+0xc0/0x100 net/socket.c:822
 SYSC_recvfrom+0x18c/0x290 net/socket.c:1815
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

The buggy address belongs to the object at ffff8880544d2840
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 271 bytes inside of
 512-byte region [ffff8880544d2840, ffff8880544d2a40)
The buggy address belongs to the page:
page:ffffea0001513480 count:1 mapcount:0 mapping:ffff8880544d20c0 index:0xffff8880544d2ac0
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffff8880544d20c0 ffff8880544d2ac0 0000000100000005
raw: ffffea0002986d20 ffffea00026d6860 ffff88812fe56940 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880544d2800: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff8880544d2880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880544d2900: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
                                                 ^
 ffff8880544d2980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880544d2a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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