xfrm: add extack to verify_sec_ctx_len

Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

net/xfrm/xfrm_user.c

@@ -102,7 +102,7 @@ static void verify_one_addr(struct nlattr **attrs, enum xfrm_attr_type_t type,
 		*addrp = nla_data(rt);
 }
 
-static inline int verify_sec_ctx_len(struct nlattr **attrs)
+static inline int verify_sec_ctx_len(struct nlattr **attrs, struct netlink_ext_ack *extack)
 {
 	struct nlattr *rt = attrs[XFRMA_SEC_CTX];
 	struct xfrm_user_sec_ctx *uctx;
@@ -112,8 +112,10 @@ static inline int verify_sec_ctx_len(struct nlattr **attrs)
 
 	uctx = nla_data(rt);
 	if (uctx->len > nla_len(rt) ||
-	    uctx->len != (sizeof(struct xfrm_user_sec_ctx) + uctx->ctx_len))
+	    uctx->len != (sizeof(struct xfrm_user_sec_ctx) + uctx->ctx_len)) {
+		NL_SET_ERR_MSG(extack, "Invalid security context length");
 		return -EINVAL;
+	}
 
 	return 0;
 }
@@ -264,7 +266,7 @@ static int verify_newsa_info(struct xfrm_usersa_info *p,
 		goto out;
 	if ((err = verify_one_alg(attrs, XFRMA_ALG_COMP)))
 		goto out;
-	if ((err = verify_sec_ctx_len(attrs)))
+	if ((err = verify_sec_ctx_len(attrs, NULL)))
 		goto out;
 	if ((err = verify_replay(p, attrs)))
 		goto out;
@@ -1800,7 +1802,7 @@ static int xfrm_add_policy(struct sk_buff *skb, struct nlmsghdr *nlh,
 	err = verify_newpolicy_info(p, extack);
 	if (err)
 		return err;
-	err = verify_sec_ctx_len(attrs);
+	err = verify_sec_ctx_len(attrs, extack);
 	if (err)
 		return err;
 
@@ -2136,7 +2138,7 @@ static int xfrm_get_policy(struct sk_buff *skb, struct nlmsghdr *nlh,
 		struct nlattr *rt = attrs[XFRMA_SEC_CTX];
 		struct xfrm_sec_ctx *ctx;
 
-		err = verify_sec_ctx_len(attrs);
+		err = verify_sec_ctx_len(attrs, extack);
 		if (err)
 			return err;
 
@@ -2441,7 +2443,7 @@ static int xfrm_add_pol_expire(struct sk_buff *skb, struct nlmsghdr *nlh,
 		struct nlattr *rt = attrs[XFRMA_SEC_CTX];
 		struct xfrm_sec_ctx *ctx;
 
-		err = verify_sec_ctx_len(attrs);
+		err = verify_sec_ctx_len(attrs, extack);
 		if (err)
 			return err;
 
@@ -2533,7 +2535,7 @@ static int xfrm_add_acquire(struct sk_buff *skb, struct nlmsghdr *nlh,
 	err = verify_newpolicy_info(&ua->policy, extack);
 	if (err)
 		goto free_state;
-	err = verify_sec_ctx_len(attrs);
+	err = verify_sec_ctx_len(attrs, extack);
 	if (err)
 		goto free_state;