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authorKees Cook <keescook@chromium.org>2021-06-17 08:34:19 -0700
committerKees Cook <keescook@chromium.org>2021-10-18 12:28:52 -0700
commitcaf283d040f53bc4fd81ce3d2a1a364b069cfd7d (patch)
treef3271a359a8741933856b597503872c068359443 /net/xfrm
parent4797632f4f1d8af4e0670adcb97bf9800dc3beca (diff)
xfrm: Use memset_after() to clear padding
In preparation for FORTIFY_SOURCE performing compile-time and run-time field bounds checking for memset(), avoid intentionally writing across neighboring fields. Clear trailing padding bytes using the new helper so that memset() doesn't get confused about writing "past the end" of the last struct member. There is no change to the resulting machine code. Cc: Steffen Klassert <steffen.klassert@secunet.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'net/xfrm')
-rw-r--r--net/xfrm/xfrm_policy.c4
-rw-r--r--net/xfrm/xfrm_user.c2
2 files changed, 2 insertions, 4 deletions
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 37d17a79617c..1a06585022ab 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -2486,9 +2486,7 @@ static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family)
xdst = dst_alloc(dst_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
if (likely(xdst)) {
- struct dst_entry *dst = &xdst->u.dst;
-
- memset(dst + 1, 0, sizeof(*xdst) - sizeof(*dst));
+ memset_after(xdst, 0, u.dst);
} else
xdst = ERR_PTR(-ENOBUFS);
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 03b66d154b2b..b7b986520dc7 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -2912,7 +2912,7 @@ static int build_expire(struct sk_buff *skb, struct xfrm_state *x, const struct
copy_to_user_state(x, &ue->state);
ue->hard = (c->data.hard != 0) ? 1 : 0;
/* clear the padding bytes */
- memset(&ue->hard + 1, 0, sizeof(*ue) - offsetofend(typeof(*ue), hard));
+ memset_after(ue, 0, hard);
err = xfrm_mark_put(skb, &x->mark);
if (err)