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. Cc: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> Cc: Jozsef Kadlecsik <kadlec@xxxxxxxxxxxxx> Cc: Florian Westphal <fw@xxxxxxxxx> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> Cc: Jakub Kicinski <kuba@xxxxxxxxxx> Cc: netfilter-devel@xxxxxxxxxxxxxxx Cc: coreteam@xxxxxxxxxxxxx Cc: netdev@xxxxxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> --- net/netfilter/nf_conntrack_core.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index d31dbccbe7bd..060503230519 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -1500,9 +1500,7 @@ __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); -- 2.30.2