sctp: correct bounds check in sctp_setsockopt_auth_key
authorVlad Yasevich <vladislav.yasevich@hp.com>
Wed, 27 Aug 2008 23:08:54 +0000 (16:08 -0700)
committerDavid S. Miller <davem@davemloft.net>
Wed, 27 Aug 2008 23:08:54 +0000 (16:08 -0700)
The bonds check to prevent buffer overlflow was not exactly
right.  It still allowed overflow of up to 8 bytes which is
sizeof(struct sctp_authkey).

Since optlen is already checked against the size of that struct,
we are guaranteed not to cause interger overflow either.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/sctp/socket.c

index afa952e726d7c9ab8b2c8951d5ffdcd87fe47aca..9b9b2c31dd15c780eac5d80e5fcae45572b781bf 100644 (file)
@@ -3144,7 +3144,7 @@ static int sctp_setsockopt_auth_key(struct sock *sk,
                goto out;
        }
 
-       if (authkey->sca_keylength > optlen) {
+       if (authkey->sca_keylength > optlen - sizeof(struct sctp_authkey)) {
                ret = -EINVAL;
                goto out;
        }