crypto: hmac - fix memory leak in hmac_init_tfm()

When I added the sanity check of 'descsize', I missed that the child
hash tfm needs to be freed if the sanity check fails.  Of course this
should never happen, hence the use of WARN_ON(), but it should be fixed.

Fixes: e1354400b25d ("crypto: hash - fix incorrect HASH_MAX_DESCSIZE")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 3 insertions, 1 deletions

diff --git a/crypto/hmac.c b/crypto/hmac.c
index 241b1868c1d0..ac8c611ee33e 100644
--- a/crypto/hmac.c
+++ b/crypto/hmac.c
@@ -157,8 +157,10 @@ static int hmac_init_tfm(struct crypto_tfm *tfm)
 
         parent->descsize = sizeof(struct shash_desc) +
                            crypto_shash_descsize(hash);
-        if (WARN_ON(parent->descsize > HASH_MAX_DESCSIZE))
+        if (WARN_ON(parent->descsize > HASH_MAX_DESCSIZE)) {
+                crypto_free_shash(hash);
                 return -EINVAL;
+        }
 
         ctx->hash = hash;
         return 0;