dccp: change L/R must have at least one byte in the dccpsf_val field

    
Thanks to Eugene Teo for reporting this problem.
    
Signed-off-by: Eugene Teo <eugenete@kernel.sg>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 0 deletions

diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index b622d9744856..1ca3b26eed0f 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -474,6 +474,11 @@ static int dccp_setsockopt_change(struct sock *sk, int type,
 
         if (copy_from_user(&opt, optval, sizeof(opt)))
                 return -EFAULT;
+        /*
+         * rfc4340: 6.1. Change Options
+         */
+        if (opt.dccpsf_len < 1)
+                return -EINVAL;
 
         val = kmalloc(opt.dccpsf_len, GFP_KERNEL);
         if (!val)