[IPV6]: Check length of optval provided by user in setsockopt().

Check length of setsockopt's optval, which provided by user, before copy it
from user space.
For POSIX compliant, return -EINVAL for setsockopt of short lengths.

Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

1 files changed, 8 insertions, 2 deletions

diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index bf9695375219..bd3fb129b393 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -449,6 +449,9 @@ done:
         {
                 struct ipv6_mreq mreq;
 
+                if (optlen < sizeof(struct ipv6_mreq))
+                        goto e_inval;
+
                 retv = -EPROTO;
                 if (inet_sk(sk)->is_icsk)
                         break;
@@ -468,7 +471,7 @@ done:
         {
                 struct ipv6_mreq mreq;
 
-                if (optlen != sizeof(struct ipv6_mreq))
+                if (optlen < sizeof(struct ipv6_mreq))
                         goto e_inval;
 
                 retv = -EFAULT;
@@ -487,6 +490,9 @@ done:
                 struct group_req greq;
                 struct sockaddr_in6 *psin6;
 
+                if (optlen < sizeof(struct group_req))
+                        goto e_inval;
+
                 retv = -EFAULT;
                 if (copy_from_user(&greq, optval, sizeof(struct group_req)))
                         break;
@@ -511,7 +517,7 @@ done:
                 struct group_source_req greqs;
                 int omode, add;
 
-                if (optlen != sizeof(struct group_source_req))
+                if (optlen < sizeof(struct group_source_req))
                         goto e_inval;
                 if (copy_from_user(&greqs, optval, sizeof(greqs))) {
                         retv = -EFAULT;