net: 802: Use memset_startat() to clear struct fields

In preparation for FORTIFY_SOURCE performing compile-time and run-time
field bounds checking for memset(), avoid intentionally writing across
neighboring fields.

Use memset_startat() so memset() doesn't get confused about writing
beyond the destination member that is intended to be the starting point
of zeroing through the end of the struct.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Kees Cook 2021-11-18 12:30:45 -08:00 committed by David S. Miller
parent f5455a1d9d
commit e3617433c3

View File

@ -65,7 +65,7 @@ static int hippi_header(struct sk_buff *skb, struct net_device *dev,
hip->le.src_addr_type = 2; /* 12 bit SC address */
memcpy(hip->le.src_switch_addr, dev->dev_addr + 3, 3);
memset(&hip->le.reserved, 0, 16);
memset_startat(&hip->le, 0, reserved);
hip->snap.dsap = HIPPI_EXTENDED_SAP;
hip->snap.ssap = HIPPI_EXTENDED_SAP;