[SCTP]: Prevent OOPS if hmac modules didn't load

SCTP was checking for NULL when trying to detect hmac
allocation failure where it should have been using IS_ERR.
Also, print a rate limited warning to the log telling the
user what happend.

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

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 83a76ba..f3c95f9 100644 (file)
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -5227,7 +5227,12 @@ int sctp_inet_listen(struct socket *sock, int backlog)
        /* Allocate HMAC for generating cookie. */
        if (sctp_hmac_alg) {
                tfm = crypto_alloc_hash(sctp_hmac_alg, 0, CRYPTO_ALG_ASYNC);
-               if (!tfm) {
+               if (IS_ERR(tfm)) {
+                       if (net_ratelimit()) {
+                               printk(KERN_INFO
+                                      "SCTP: failed to load transform for %s: %ld\n",
+                                       sctp_hmac_alg, PTR_ERR(tfm));
+                       }
                        err = -ENOSYS;
                        goto out;
                }