Hi Stephan,
On 11/11/2014 05:37 AM, Stephan Mueller wrote:
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@xxxxxxxxxx>
---
crypto/algif_hash.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c
index 8502462..f75db4c 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,
Perhaps something like this (alternatively kzfree() would work, too) ...
static void __sock_kfree_s(struct sock *sk, void *mem, int size,
bool clear_mem)
{
if (WARN_ON_ONCE(!mem))
return;
if (clear_mem)
memzero_explicit(mem, size);
kfree(mem);
atomic_sub(size, &sk->sk_omem_alloc);
}
void sock_kfree_s(struct sock *sk, void *mem, int size)
{
__sock_kfree_s(sk, mem, size, false);
}
EXPORT_SYMBOL(sock_kfree_s);
void sock_kzfree_s(struct sock *sk, void *mem, int size)
{
__sock_kfree_s(sk, mem, size, true);
}
EXPORT_SYMBOL(sock_kzfree_s);
... so you could then just use it as drop-in in various places:
sock_kzfree_s(sk, ctx->result, ...);
crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req)));
sock_kfree_s(sk, ctx, ctx->len);
Thanks,
Daniel
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