From: Kees Cook Date: Thu, 18 Nov 2021 20:31:13 +0000 (-0800) Subject: netfilter: conntrack: Use memset_startat() to zero struct nf_conn X-Git-Tag: v5.17-rc1~170^2~178^2~5 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=4be1dbb75c3de6af1888fa79778388fd4e529543;p=thirdparty%2Fkernel%2Flinux.git 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 Signed-off-by: Pablo Neira Ayuso --- diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 054ee9d25efe1..aa657db183183 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -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);