crypto: user - ensure user supplied strings are nul-terminated

To avoid misuse, ensure cru_name and cru_driver_name are always
nul-terminated strings.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 14 insertions, 0 deletions

diff --git a/crypto/crypto_user.c b/crypto/crypto_user.c
index 423a267022f4..dfd511fb39ee 100644
--- a/crypto/crypto_user.c
+++ b/crypto/crypto_user.c
@@ -30,6 +30,8 @@
 
 #include "internal.h"
 
+#define null_terminated(x)      (strnlen(x, sizeof(x)) < sizeof(x))
+
 static DEFINE_MUTEX(crypto_cfg_mutex);
 
 /* The crypto netlink socket */
@@ -196,6 +198,9 @@ static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
         struct crypto_dump_info info;
         int err;
 
+        if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
+                return -EINVAL;
+
         if (!p->cru_driver_name[0])
                 return -EINVAL;
 
@@ -260,6 +265,9 @@ static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
         struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
         LIST_HEAD(list);
 
+        if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
+                return -EINVAL;
+
         if (priority && !strlen(p->cru_driver_name))
                 return -EINVAL;
 
@@ -287,6 +295,9 @@ static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
         struct crypto_alg *alg;
         struct crypto_user_alg *p = nlmsg_data(nlh);
 
+        if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
+                return -EINVAL;
+
         alg = crypto_alg_match(p, 1);
         if (!alg)
                 return -ENOENT;
@@ -368,6 +379,9 @@ static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
         struct crypto_user_alg *p = nlmsg_data(nlh);
         struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
 
+        if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
+                return -EINVAL;
+
         if (strlen(p->cru_driver_name))
                 exact = 1;