crypto: algif - zeroize IV buffer

Zeroize the buffer holding the IV used for the completed
cipher operation before the buffer is released by the
skcipher AF_ALG interface handler.
Signed-off-by: NStephan Mueller <smueller@chronox.de>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

crypto/algif_skcipher.c

@@ -566,6 +566,7 @@ static void skcipher_sock_destruct(struct sock *sk)
 	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(&ctx->req);
 
 	skcipher_free_sgl(sk);
+	memzero_explicit(ctx->iv, crypto_ablkcipher_ivsize(tfm));
 	sock_kfree_s(sk, ctx->iv, crypto_ablkcipher_ivsize(tfm));
 	sock_kfree_s(sk, ctx, ctx->len);
 	af_alg_release_parent(sk);