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authorHerbert Xu <herbert@gondor.apana.org.au>2016-09-01 12:16:44 +0300
committerHerbert Xu <herbert@gondor.apana.org.au>2016-09-07 16:08:28 +0300
commit493b2ed3f7603a15ff738553384d5a4510ffeb95 (patch)
tree064221b1febbd2629423bebea8673f830689490a /crypto/algif_hash.c
parent5ba1c7b5ffc16ecf245f41805e46f7351c115e57 (diff)
downloadlinux-493b2ed3f7603a15ff738553384d5a4510ffeb95.tar.xz
crypto: algif_hash - Handle NULL hashes correctly
Right now attempting to read an empty hash simply returns zeroed bytes, this patch corrects this by calling the digest function using an empty input. Reported-by: Russell King - ARM Linux <linux@armlinux.org.uk> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/algif_hash.c')
-rw-r--r--crypto/algif_hash.c73
1 files changed, 61 insertions, 12 deletions
diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c
index 68a5ceaa04c8..2d8466f9e49b 100644
--- a/crypto/algif_hash.c
+++ b/crypto/algif_hash.c
@@ -39,6 +39,37 @@ struct algif_hash_tfm {
bool has_key;
};
+static int hash_alloc_result(struct sock *sk, struct hash_ctx *ctx)
+{
+ unsigned ds;
+
+ if (ctx->result)
+ return 0;
+
+ ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));
+
+ ctx->result = sock_kmalloc(sk, ds, GFP_KERNEL);
+ if (!ctx->result)
+ return -ENOMEM;
+
+ memset(ctx->result, 0, ds);
+
+ return 0;
+}
+
+static void hash_free_result(struct sock *sk, struct hash_ctx *ctx)
+{
+ unsigned ds;
+
+ if (!ctx->result)
+ return;
+
+ ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));
+
+ sock_kzfree_s(sk, ctx->result, ds);
+ ctx->result = NULL;
+}
+
static int hash_sendmsg(struct socket *sock, struct msghdr *msg,
size_t ignored)
{
@@ -54,6 +85,9 @@ static int hash_sendmsg(struct socket *sock, struct msghdr *msg,
lock_sock(sk);
if (!ctx->more) {
+ if ((msg->msg_flags & MSG_MORE))
+ hash_free_result(sk, ctx);
+
err = af_alg_wait_for_completion(crypto_ahash_init(&ctx->req),
&ctx->completion);
if (err)
@@ -90,6 +124,10 @@ static int hash_sendmsg(struct socket *sock, struct msghdr *msg,
ctx->more = msg->msg_flags & MSG_MORE;
if (!ctx->more) {
+ err = hash_alloc_result(sk, ctx);
+ if (err)
+ goto unlock;
+
ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req),
&ctx->completion);
@@ -116,6 +154,13 @@ static ssize_t hash_sendpage(struct socket *sock, struct page *page,
sg_init_table(ctx->sgl.sg, 1);
sg_set_page(ctx->sgl.sg, page, size, offset);
+ if (!(flags & MSG_MORE)) {
+ err = hash_alloc_result(sk, ctx);
+ if (err)
+ goto unlock;
+ } else if (!ctx->more)
+ hash_free_result(sk, ctx);
+
ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, ctx->result, size);
if (!(flags & MSG_MORE)) {
@@ -153,6 +198,7 @@ static int hash_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
struct alg_sock *ask = alg_sk(sk);
struct hash_ctx *ctx = ask->private;
unsigned ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));
+ bool result;
int err;
if (len > ds)
@@ -161,17 +207,29 @@ static int hash_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
msg->msg_flags |= MSG_TRUNC;
lock_sock(sk);
+ result = ctx->result;
+ err = hash_alloc_result(sk, ctx);
+ if (err)
+ goto unlock;
+
+ ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
+
if (ctx->more) {
ctx->more = 0;
- ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req),
&ctx->completion);
if (err)
goto unlock;
+ } else if (!result) {
+ err = af_alg_wait_for_completion(
+ crypto_ahash_digest(&ctx->req),
+ &ctx->completion);
}
err = memcpy_to_msg(msg, ctx->result, len);
+ hash_free_result(sk, ctx);
+
unlock:
release_sock(sk);
@@ -394,8 +452,7 @@ static void hash_sock_destruct(struct sock *sk)
struct alg_sock *ask = alg_sk(sk);
struct hash_ctx *ctx = ask->private;
- sock_kzfree_s(sk, ctx->result,
- crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req)));
+ hash_free_result(sk, ctx);
sock_kfree_s(sk, ctx, ctx->len);
af_alg_release_parent(sk);
}
@@ -407,20 +464,12 @@ static int hash_accept_parent_nokey(void *private, struct sock *sk)
struct algif_hash_tfm *tfm = private;
struct crypto_ahash *hash = tfm->hash;
unsigned len = sizeof(*ctx) + crypto_ahash_reqsize(hash);
- unsigned ds = crypto_ahash_digestsize(hash);
ctx = sock_kmalloc(sk, len, GFP_KERNEL);
if (!ctx)
return -ENOMEM;
- ctx->result = sock_kmalloc(sk, ds, GFP_KERNEL);
- if (!ctx->result) {
- sock_kfree_s(sk, ctx, len);
- return -ENOMEM;
- }
-
- memset(ctx->result, 0, ds);
-
+ ctx->result = NULL;
ctx->len = len;
ctx->more = 0;
af_alg_init_completion(&ctx->completion);