sctp: use vmemdup_user() rather than badly open-coding memdup_user()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 3204a9b..c2cccc9 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -970,13 +970,6 @@ int sctp_asconf_mgmt(struct sctp_sock *sp, struct sctp_sockaddr_entry *addrw)
* This is used for tunneling the sctp_bindx() request through sctp_setsockopt()
* from userspace.
*
- * We don't use copy_from_user() for optimization: we first do the
- * sanity checks (buffer size -fast- and access check-healthy
- * pointer); if all of those succeed, then we can alloc the memory
- * (expensive operation) needed to copy the data to kernel. Then we do
- * the copying without checking the user space area
- * (__copy_from_user()).
- *
* On exit there is no need to do sockfd_put(), sys_setsockopt() does
* it.
*
@@ -1006,25 +999,15 @@ static int sctp_setsockopt_bindx(struct sock *sk,
if (unlikely(addrs_size <= 0))
return -EINVAL;
- /* Check the user passed a healthy pointer. */
- if (unlikely(!access_ok(VERIFY_READ, addrs, addrs_size)))
- return -EFAULT;
-
- /* Alloc space for the address array in kernel memory. */
- kaddrs = kmalloc(addrs_size, GFP_USER | __GFP_NOWARN);
- if (unlikely(!kaddrs))
- return -ENOMEM;
-
- if (__copy_from_user(kaddrs, addrs, addrs_size)) {
- kfree(kaddrs);
- return -EFAULT;
- }
+ kaddrs = vmemdup_user(addrs, addrs_size);
+ if (unlikely(IS_ERR(kaddrs)))
+ return PTR_ERR(kaddrs);
/* Walk through the addrs buffer and count the number of addresses. */
addr_buf = kaddrs;
while (walk_size < addrs_size) {
if (walk_size + sizeof(sa_family_t) > addrs_size) {
- kfree(kaddrs);
+ kvfree(kaddrs);
return -EINVAL;
}
@@ -1035,7 +1018,7 @@ static int sctp_setsockopt_bindx(struct sock *sk,
* causes the address buffer to overflow return EINVAL.
*/
if (!af || (walk_size + af->sockaddr_len) > addrs_size) {
- kfree(kaddrs);
+ kvfree(kaddrs);
return -EINVAL;
}
addrcnt++;
@@ -1065,7 +1048,7 @@ static int sctp_setsockopt_bindx(struct sock *sk,
}
out:
- kfree(kaddrs);
+ kvfree(kaddrs);
return err;
}
@@ -1323,13 +1306,6 @@ static int __sctp_connect(struct sock *sk,
* land and invoking either sctp_connectx(). This is used for tunneling
* the sctp_connectx() request through sctp_setsockopt() from userspace.
*
- * We don't use copy_from_user() for optimization: we first do the
- * sanity checks (buffer size -fast- and access check-healthy
- * pointer); if all of those succeed, then we can alloc the memory
- * (expensive operation) needed to copy the data to kernel. Then we do
- * the copying without checking the user space area
- * (__copy_from_user()).
- *
* On exit there is no need to do sockfd_put(), sys_setsockopt() does
* it.
*
@@ -1345,7 +1321,6 @@ static int __sctp_setsockopt_connectx(struct sock *sk,
sctp_assoc_t *assoc_id)
{
struct sockaddr *kaddrs;
- gfp_t gfp = GFP_KERNEL;
int err = 0;
pr_debug("%s: sk:%p addrs:%p addrs_size:%d\n",
@@ -1354,24 +1329,12 @@ static int __sctp_setsockopt_connectx(struct sock *sk,
if (unlikely(addrs_size <= 0))
return -EINVAL;
- /* Check the user passed a healthy pointer. */
- if (unlikely(!access_ok(VERIFY_READ, addrs, addrs_size)))
- return -EFAULT;
+ kaddrs = vmemdup_user(addrs, addrs_size);
+ if (unlikely(IS_ERR(kaddrs)))
+ return PTR_ERR(kaddrs);
- /* Alloc space for the address array in kernel memory. */
- if (sk->sk_socket->file)
- gfp = GFP_USER | __GFP_NOWARN;
- kaddrs = kmalloc(addrs_size, gfp);
- if (unlikely(!kaddrs))
- return -ENOMEM;
-
- if (__copy_from_user(kaddrs, addrs, addrs_size)) {
- err = -EFAULT;
- } else {
- err = __sctp_connect(sk, kaddrs, addrs_size, assoc_id);
- }
-
- kfree(kaddrs);
+ err = __sctp_connect(sk, kaddrs, addrs_size, assoc_id);
+ kvfree(kaddrs);
return err;
}
