netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'.
==================================================================
BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:373 [inline]
BUG: KASAN: slab-out-of-bounds in fbcon_get_font+0x2f4/0x6f0 drivers/video/fbdev/core/fbcon.c:2274
Read of size 6 at addr ffff88809058b44c by task syz-executor.0/14275

CPU: 1 PID: 14275 Comm: syz-executor.0 Not tainted 4.19.148-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+0x22c/0x33e lib/dump_stack.c:118
 print_address_description.cold+0x56/0x25c mm/kasan/report.c:256
 kasan_report_error.cold+0x66/0xb9 mm/kasan/report.c:354
 kasan_report+0x8f/0x96 mm/kasan/report.c:412
 memcpy+0x20/0x50 mm/kasan/kasan.c:302
 memcpy include/linux/string.h:373 [inline]
 fbcon_get_font+0x2f4/0x6f0 drivers/video/fbdev/core/fbcon.c:2274
 con_font_get drivers/tty/vt/vt.c:4445 [inline]
 con_font_op+0x1f7/0x1140 drivers/tty/vt/vt.c:4604
 vt_ioctl+0x17cf/0x2af0 drivers/tty/vt/vt_ioctl.c:990
 tty_ioctl+0x5b0/0x1420 drivers/tty/tty_io.c:2669
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688
 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
 do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45dd99
Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f44b1de8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000010880 RCX: 000000000045dd99
RDX: 0000000020000100 RSI: 0000000000004b72 RDI: 0000000000000004
RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007ffdffc15bff R14: 00007f44b1de99c0 R15: 000000000118bf2c

Allocated by task 12339:
 __do_kmalloc mm/slab.c:3727 [inline]
 __kmalloc+0x15a/0x4f0 mm/slab.c:3736
 kmalloc include/linux/slab.h:520 [inline]
 fbcon_set_font+0x421/0xc60 drivers/video/fbdev/core/fbcon.c:2467
 con_font_set drivers/tty/vt/vt.c:4537 [inline]
 con_font_op+0xd2b/0x1140 drivers/tty/vt/vt.c:4602
 vt_ioctl+0x128c/0x2af0 drivers/tty/vt/vt_ioctl.c:938
 tty_ioctl+0x5b0/0x1420 drivers/tty/tty_io.c:2669
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688
 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
 do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 3724:
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcc/0x250 mm/slab.c:3822
 skb_free_head net/core/skbuff.c:554 [inline]
 skb_release_data+0x6ea/0x930 net/core/skbuff.c:574
 skb_release_all net/core/skbuff.c:631 [inline]
 __kfree_skb net/core/skbuff.c:645 [inline]
 consume_skb+0x113/0x3e0 net/core/skbuff.c:705
 skb_free_datagram+0x16/0xf0 net/core/datagram.c:329
 netlink_recvmsg+0x63f/0xf30 net/netlink/af_netlink.c:1988
 sock_recvmsg_nosec net/socket.c:795 [inline]
 sock_recvmsg+0xca/0x110 net/socket.c:802
 ___sys_recvmsg+0x255/0x570 net/socket.c:2277
 __sys_recvmsg net/socket.c:2326 [inline]
 __do_sys_recvmsg net/socket.c:2336 [inline]
 __se_sys_recvmsg net/socket.c:2333 [inline]
 __x64_sys_recvmsg+0x12f/0x220 net/socket.c:2333
 do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88809058b340
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 268 bytes inside of
 512-byte region [ffff88809058b340, ffff88809058b540)
The buggy address belongs to the page:
page:ffffea00024162c0 count:1 mapcount:0 mapping:ffff88812c3f6940 index:0x0
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffffea00022602c8 ffffea000229bd88 ffff88812c3f6940
raw: 0000000000000000 ffff88809058b0c0 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809058b300: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff88809058b380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88809058b400: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
                                                 ^
 ffff88809058b480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88809058b500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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