linux/crypto/algif_hash.c
Herbert Xu 4afa5f9617 crypto: algif_hash - Only export and import on sockets with data
The hash_accept call fails to work on sockets that have not received
any data.  For some algorithm implementations it may cause crashes.

This patch fixes this by ensuring that we only export and import on
sockets that have received data.

Cc: stable@vger.kernel.org
Reported-by: Harsh Jain <harshjain.prof@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Stephan Mueller <smueller@chronox.de>
2015-11-02 17:48:30 +08:00

322 lines
6.7 KiB
C

/*
* algif_hash: User-space interface for hash algorithms
*
* This file provides the user-space API for hash algorithms.
*
* Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
*/
#include <crypto/hash.h>
#include <crypto/if_alg.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/net.h>
#include <net/sock.h>
struct hash_ctx {
struct af_alg_sgl sgl;
u8 *result;
struct af_alg_completion completion;
unsigned int len;
bool more;
struct ahash_request req;
};
static int hash_sendmsg(struct socket *sock, struct msghdr *msg,
size_t ignored)
{
int limit = ALG_MAX_PAGES * PAGE_SIZE;
struct sock *sk = sock->sk;
struct alg_sock *ask = alg_sk(sk);
struct hash_ctx *ctx = ask->private;
long copied = 0;
int err;
if (limit > sk->sk_sndbuf)
limit = sk->sk_sndbuf;
lock_sock(sk);
if (!ctx->more) {
err = crypto_ahash_init(&ctx->req);
if (err)
goto unlock;
}
ctx->more = 0;
while (msg_data_left(msg)) {
int len = msg_data_left(msg);
if (len > limit)
len = limit;
len = af_alg_make_sg(&ctx->sgl, &msg->msg_iter, len);
if (len < 0) {
err = copied ? 0 : len;
goto unlock;
}
ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, NULL, len);
err = af_alg_wait_for_completion(crypto_ahash_update(&ctx->req),
&ctx->completion);
af_alg_free_sg(&ctx->sgl);
if (err)
goto unlock;
copied += len;
iov_iter_advance(&msg->msg_iter, len);
}
err = 0;
ctx->more = msg->msg_flags & MSG_MORE;
if (!ctx->more) {
ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
err = af_alg_wait_for_completion(crypto_ahash_final(&ctx->req),
&ctx->completion);
}
unlock:
release_sock(sk);
return err ?: copied;
}
static ssize_t hash_sendpage(struct socket *sock, struct page *page,
int offset, size_t size, int flags)
{
struct sock *sk = sock->sk;
struct alg_sock *ask = alg_sk(sk);
struct hash_ctx *ctx = ask->private;
int err;
if (flags & MSG_SENDPAGE_NOTLAST)
flags |= MSG_MORE;
lock_sock(sk);
sg_init_table(ctx->sgl.sg, 1);
sg_set_page(ctx->sgl.sg, page, size, offset);
ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, ctx->result, size);
if (!(flags & MSG_MORE)) {
if (ctx->more)
err = crypto_ahash_finup(&ctx->req);
else
err = crypto_ahash_digest(&ctx->req);
} else {
if (!ctx->more) {
err = crypto_ahash_init(&ctx->req);
if (err)
goto unlock;
}
err = crypto_ahash_update(&ctx->req);
}
err = af_alg_wait_for_completion(err, &ctx->completion);
if (err)
goto unlock;
ctx->more = flags & MSG_MORE;
unlock:
release_sock(sk);
return err ?: size;
}
static int hash_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
int flags)
{
struct sock *sk = sock->sk;
struct alg_sock *ask = alg_sk(sk);
struct hash_ctx *ctx = ask->private;
unsigned ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));
int err;
if (len > ds)
len = ds;
else if (len < ds)
msg->msg_flags |= MSG_TRUNC;
lock_sock(sk);
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;
}
err = memcpy_to_msg(msg, ctx->result, len);
unlock:
release_sock(sk);
return err ?: len;
}
static int hash_accept(struct socket *sock, struct socket *newsock, int flags)
{
struct sock *sk = sock->sk;
struct alg_sock *ask = alg_sk(sk);
struct hash_ctx *ctx = ask->private;
struct ahash_request *req = &ctx->req;
char state[crypto_ahash_statesize(crypto_ahash_reqtfm(req))];
struct sock *sk2;
struct alg_sock *ask2;
struct hash_ctx *ctx2;
bool more;
int err;
lock_sock(sk);
more = ctx->more;
err = more ? crypto_ahash_export(req, state) : 0;
release_sock(sk);
if (err)
return err;
err = af_alg_accept(ask->parent, newsock);
if (err)
return err;
sk2 = newsock->sk;
ask2 = alg_sk(sk2);
ctx2 = ask2->private;
ctx2->more = more;
if (!more)
return err;
err = crypto_ahash_import(&ctx2->req, state);
if (err) {
sock_orphan(sk2);
sock_put(sk2);
}
return err;
}
static struct proto_ops algif_hash_ops = {
.family = PF_ALG,
.connect = sock_no_connect,
.socketpair = sock_no_socketpair,
.getname = sock_no_getname,
.ioctl = sock_no_ioctl,
.listen = sock_no_listen,
.shutdown = sock_no_shutdown,
.getsockopt = sock_no_getsockopt,
.mmap = sock_no_mmap,
.bind = sock_no_bind,
.setsockopt = sock_no_setsockopt,
.poll = sock_no_poll,
.release = af_alg_release,
.sendmsg = hash_sendmsg,
.sendpage = hash_sendpage,
.recvmsg = hash_recvmsg,
.accept = hash_accept,
};
static void *hash_bind(const char *name, u32 type, u32 mask)
{
return crypto_alloc_ahash(name, type, mask);
}
static void hash_release(void *private)
{
crypto_free_ahash(private);
}
static int hash_setkey(void *private, const u8 *key, unsigned int keylen)
{
return crypto_ahash_setkey(private, key, keylen);
}
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)));
sock_kfree_s(sk, ctx, ctx->len);
af_alg_release_parent(sk);
}
static int hash_accept_parent(void *private, struct sock *sk)
{
struct hash_ctx *ctx;
struct alg_sock *ask = alg_sk(sk);
unsigned len = sizeof(*ctx) + crypto_ahash_reqsize(private);
unsigned ds = crypto_ahash_digestsize(private);
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->len = len;
ctx->more = 0;
af_alg_init_completion(&ctx->completion);
ask->private = ctx;
ahash_request_set_tfm(&ctx->req, private);
ahash_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
af_alg_complete, &ctx->completion);
sk->sk_destruct = hash_sock_destruct;
return 0;
}
static const struct af_alg_type algif_type_hash = {
.bind = hash_bind,
.release = hash_release,
.setkey = hash_setkey,
.accept = hash_accept_parent,
.ops = &algif_hash_ops,
.name = "hash",
.owner = THIS_MODULE
};
static int __init algif_hash_init(void)
{
return af_alg_register_type(&algif_type_hash);
}
static void __exit algif_hash_exit(void)
{
int err = af_alg_unregister_type(&algif_type_hash);
BUG_ON(err);
}
module_init(algif_hash_init);
module_exit(algif_hash_exit);
MODULE_LICENSE("GPL");