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From:   Mark Salyzyn <salyzyn@android.com>
To:     linux-kernel@vger.kernel.org
Cc:     kernel-team@android.com, Mark Salyzyn <salyzyn@android.com>,
        netdev@vger.kernel.org,
        Steffen Klassert <steffen.klassert@secunet.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>
Subject: af_key: pfkey_dump needs parameter validation
Date:   Tue, 21 Jul 2020 06:23:54 -0700
Message-Id: <20200721132358.966099-1-salyzyn@android.com>
MIME-Version: 1.0
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Sender: linux-kernel-owner@vger.kernel.org
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In pfkey_dump() dplen and splen can both be specified to access the
xfrm_address_t structure out of bounds in__xfrm_state_filter_match()
when it calls addr_match() with the indexes.  Return EINVAL if either
are out of range.

Signed-off-by: Mark Salyzyn <salyzyn@android.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: kernel-team@android.com
---
Should be back ported to the stable queues because this is a out of
bounds access.

 net/key/af_key.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/net/key/af_key.c b/net/key/af_key.c
index b67ed3a8486c..dd2a684879de 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -1849,6 +1849,13 @@ static int pfkey_dump(struct sock *sk, struct sk_buff *skb, const struct sadb_ms
 	if (ext_hdrs[SADB_X_EXT_FILTER - 1]) {
 		struct sadb_x_filter *xfilter = ext_hdrs[SADB_X_EXT_FILTER - 1];
 
+		if ((xfilter->sadb_x_filter_splen >=
+			(sizeof(xfrm_address_t) << 3)) ||
+		    (xfilter->sadb_x_filter_dplen >=
+			(sizeof(xfrm_address_t) << 3))) {
+			mutex_unlock(&pfk->dump_lock);
+			return -EINVAL;
+		}
 		filter = kmalloc(sizeof(*filter), GFP_KERNEL);
 		if (filter == NULL) {
 			mutex_unlock(&pfk->dump_lock);
-- 
2.28.0.rc0.105.gf9edc3c819-goog