From 2c93eb86f83e6006c013050d2452e15732850bd7 Mon Sep 17 00:00:00 2001
From: Mark Salyzyn <salyzyn@android.com>
Date: Wed, 22 Jul 2020 04:00:53 -0700
Subject: [PATCH 06/12] af_key: pfkey_dump needs parameter validation
Git-commit: 37bd22420f856fcd976989f1d4f1f7ad28e1fcac
Patch-mainline: v5.8
References: CVE-2021-0605 bsc#1187601

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
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>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Denis Kirjanov <dkirjanov@suse.com>
---
 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 1c619ca4198b..b9eb17306d62 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -1855,6 +1855,13 @@ 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);
-- 
2.16.4