crypto: algif - zeroize message digest buffer

Zeroize the buffer holding the message digest calculated for the
consumer before the buffer is released by the hash AF_ALG interface
handler.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 2 insertions, 0 deletions

diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c
index 850246206b12..f75db4ce48bf 100644
--- a/crypto/algif_hash.c
+++ b/crypto/algif_hash.c
@@ -258,6 +258,8 @@ static void hash_sock_destruct(struct sock *sk)
         struct alg_sock *ask = alg_sk(sk);
         struct hash_ctx *ctx = ask->private;
 
+        memzero_explicit(ctx->result,
+                     crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req)));
         sock_kfree_s(sk, ctx->result,
                      crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req)));
         sock_kfree_s(sk, ctx, ctx->len);