kpriv/linux-hardened
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

crypto: algif_hash - Handle NULL hashes correctly

Browse source 
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>
This commit is contained in:
Herbert Xu 2016-09-01 17:16:44 +08:00
parent 5ba1c7b5ff
commit 493b2ed3f7
1 changed files with 61 additions and 12 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

73
crypto/algif_hash.c
View file

@ -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);