netfilter: conntrack: Use memset_startat() to zero struct nf_conn

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() to avoid confusing memset() about writing beyond
the target struct member.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Kees Cook 2021-11-18 12:31:13 -08:00 committed by Pablo Neira Ayuso
parent fc5e0352cc
commit 4be1dbb75c

View File

@ -1562,9 +1562,7 @@ __nf_conntrack_alloc(struct net *net,
ct->status = 0;
ct->timeout = 0;
write_pnet(&ct->ct_net, net);
memset(&ct->__nfct_init_offset, 0,
offsetof(struct nf_conn, proto) -
offsetof(struct nf_conn, __nfct_init_offset));
memset_after(ct, 0, __nfct_init_offset);
nf_ct_zone_add(ct, zone);