1 files changed, 30 insertions, 57 deletions

diff --git a/net/compat.c b/net/compat.c
index bc8aeefddf3f..3236b4167a32 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -31,81 +31,54 @@
 #include <asm/uaccess.h>
 #include <net/compat.h>
 
-static inline int iov_from_user_compat_to_kern(struct iovec *kiov,
-					  struct compat_iovec __user *uiov32,
-					  int niov)
+ssize_t get_compat_msghdr(struct msghdr *kmsg,
+			  struct compat_msghdr __user *umsg,
+			  struct sockaddr __user **save_addr,
+			  struct iovec **iov)
 {
-	int tot_len = 0;
-
-	while (niov > 0) {
-		compat_uptr_t buf;
-		compat_size_t len;
-
-		if (get_user(len, &uiov32->iov_len) ||
-		    get_user(buf, &uiov32->iov_base))
-			return -EFAULT;
-
-		if (len > INT_MAX - tot_len)
-			len = INT_MAX - tot_len;
-
-		tot_len += len;
-		kiov->iov_base = compat_ptr(buf);
-		kiov->iov_len = (__kernel_size_t) len;
-		uiov32++;
-		kiov++;
-		niov--;
-	}
-	return tot_len;
-}
-
-int get_compat_msghdr(struct msghdr *kmsg, struct compat_msghdr __user *umsg)
-{
-	compat_uptr_t tmp1, tmp2, tmp3;
+	compat_uptr_t uaddr, uiov, tmp3;
+	compat_size_t nr_segs;
+	ssize_t err;
 
 	if (!access_ok(VERIFY_READ, umsg, sizeof(*umsg)) ||
-	    __get_user(tmp1, &umsg->msg_name) ||
+	    __get_user(uaddr, &umsg->msg_name) ||
 	    __get_user(kmsg->msg_namelen, &umsg->msg_namelen) ||
-	    __get_user(tmp2, &umsg->msg_iov) ||
-	    __get_user(kmsg->msg_iovlen, &umsg->msg_iovlen) ||
+	    __get_user(uiov, &umsg->msg_iov) ||
+	    __get_user(nr_segs, &umsg->msg_iovlen) ||
 	    __get_user(tmp3, &umsg->msg_control) ||
 	    __get_user(kmsg->msg_controllen, &umsg->msg_controllen) ||
 	    __get_user(kmsg->msg_flags, &umsg->msg_flags))
 		return -EFAULT;
 	if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
 		kmsg->msg_namelen = sizeof(struct sockaddr_storage);
-	kmsg->msg_name = compat_ptr(tmp1);
-	kmsg->msg_iov = compat_ptr(tmp2);
 	kmsg->msg_control = compat_ptr(tmp3);
-	return 0;
-}
 
-/* I've named the args so it is easy to tell whose space the pointers are in. */
-int verify_compat_iovec(struct msghdr *kern_msg, struct iovec *kern_iov,
-		   struct sockaddr_storage *kern_address, int mode)
-{
-	int tot_len;
+	if (save_addr)
+		*save_addr = compat_ptr(uaddr);
 
-	if (kern_msg->msg_name && kern_msg->msg_namelen) {
-		if (mode == VERIFY_READ) {
-			int err = move_addr_to_kernel(kern_msg->msg_name,
-						      kern_msg->msg_namelen,
-						      kern_address);
+	if (uaddr && kmsg->msg_namelen) {
+		if (!save_addr) {
+			err = move_addr_to_kernel(compat_ptr(uaddr),
+						  kmsg->msg_namelen,
+						  kmsg->msg_name);
 			if (err < 0)
 				return err;
 		}
-		kern_msg->msg_name = kern_address;
 	} else {
-		kern_msg->msg_name = NULL;
-		kern_msg->msg_namelen = 0;
+		kmsg->msg_name = NULL;
+		kmsg->msg_namelen = 0;
 	}
 
-	tot_len = iov_from_user_compat_to_kern(kern_iov,
-					  (struct compat_iovec __user *)kern_msg->msg_iov,
-					  kern_msg->msg_iovlen);
-	if (tot_len >= 0)
-		kern_msg->msg_iov = kern_iov;
+	if (nr_segs > UIO_MAXIOV)
+		return -EMSGSIZE;
 
-	return tot_len;
+	err = compat_rw_copy_check_uvector(save_addr ? READ : WRITE,
+					   compat_ptr(uiov), nr_segs,
+					   UIO_FASTIOV, *iov, iov);
+	if (err >= 0)
+		iov_iter_init(&kmsg->msg_iter, save_addr ? READ : WRITE,
+			      *iov, nr_segs, err);
+	return err;
 }
 
 /* Bleech... */
@@ -740,7 +713,7 @@ COMPAT_SYSCALL_DEFINE3(sendmsg, int, fd, struct compat_msghdr __user *, msg, uns
 {
 	if (flags & MSG_CMSG_COMPAT)
 		return -EINVAL;
-	return __sys_sendmsg(fd, (struct msghdr __user *)msg, flags | MSG_CMSG_COMPAT);
+	return __sys_sendmsg(fd, (struct user_msghdr __user *)msg, flags | MSG_CMSG_COMPAT);
 }
 
 COMPAT_SYSCALL_DEFINE4(sendmmsg, int, fd, struct compat_mmsghdr __user *, mmsg,
@@ -756,7 +729,7 @@ COMPAT_SYSCALL_DEFINE3(recvmsg, int, fd, struct compat_msghdr __user *, msg, uns
 {
 	if (flags & MSG_CMSG_COMPAT)
 		return -EINVAL;
-	return __sys_recvmsg(fd, (struct msghdr __user *)msg, flags | MSG_CMSG_COMPAT);
+	return __sys_recvmsg(fd, (struct user_msghdr __user *)msg, flags | MSG_CMSG_COMPAT);
 }
 
 COMPAT_SYSCALL_DEFINE4(recv, int, fd, void __user *, buf, compat_size_t, len, unsigned int, flags)