Commit a7526eb5 authored by Andy Lutomirski's avatar Andy Lutomirski Committed by David S. Miller
Browse files

net: Unbreak compat_sys_{send,recv}msg 



I broke them in this commit:

    commit 1be374a0
    Author: Andy Lutomirski <luto@amacapital.net>
    Date:   Wed May 22 14:07:44 2013 -0700

        net: Block MSG_CMSG_COMPAT in send(m)msg and recv(m)msg

This patch adds __sys_sendmsg and __sys_sendmsg as common helpers that accept
MSG_CMSG_COMPAT and blocks MSG_CMSG_COMPAT at the syscall entrypoints.  It
also reverts some unnecessary checks in sys_socketcall.

Apparently I was suffering from underscore blindness the first time around.

Signed-off-by: default avatarAndy Lutomirski <luto@amacapital.net>
Tested-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 4d3797d7

include/linux/socket.h

+3 −0
Original line number Diff line number Diff line
@@ -320,6 +320,9 @@ extern int put_cmsg(struct msghdr*, int level, int type, int len, void *data); 


struct timespec;



/* The __sys_...msg variants allow MSG_CMSG_COMPAT */

extern long __sys_recvmsg(int fd, struct msghdr __user *msg, unsigned flags);

extern long __sys_sendmsg(int fd, struct msghdr __user *msg, unsigned flags);

extern int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen,

			  unsigned int flags, struct timespec *timeout);

extern int __sys_sendmmsg(int fd, struct mmsghdr __user *mmsg,

net/compat.c

+11 −2
Original line number Diff line number Diff line
@@ -734,19 +734,25 @@ static unsigned char nas[21] = { 


asmlinkage long compat_sys_sendmsg(int fd, struct compat_msghdr __user *msg, unsigned int flags)

{

	return sys_sendmsg(fd, (struct msghdr __user *)msg, flags | MSG_CMSG_COMPAT);

	if (flags & MSG_CMSG_COMPAT)

		return -EINVAL;

	return __sys_sendmsg(fd, (struct msghdr __user *)msg, flags | MSG_CMSG_COMPAT);

}



asmlinkage long compat_sys_sendmmsg(int fd, struct compat_mmsghdr __user *mmsg,

				    unsigned int vlen, unsigned int flags)

{

	if (flags & MSG_CMSG_COMPAT)

		return -EINVAL;

	return __sys_sendmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,

			      flags | MSG_CMSG_COMPAT);

}



asmlinkage long compat_sys_recvmsg(int fd, struct compat_msghdr __user *msg, unsigned int flags)

{

	return sys_recvmsg(fd, (struct msghdr __user *)msg, flags | MSG_CMSG_COMPAT);

	if (flags & MSG_CMSG_COMPAT)

		return -EINVAL;

	return __sys_recvmsg(fd, (struct msghdr __user *)msg, flags | MSG_CMSG_COMPAT);

}



asmlinkage long compat_sys_recv(int fd, void __user *buf, size_t len, unsigned int flags)
@@ -768,6 +774,9 @@ asmlinkage long compat_sys_recvmmsg(int fd, struct compat_mmsghdr __user *mmsg, 
	int datagrams;

	struct timespec ktspec;



	if (flags & MSG_CMSG_COMPAT)

		return -EINVAL;



	if (COMPAT_USE_64BIT_TIME)

		return __sys_recvmmsg(fd, (struct mmsghdr __user *)mmsg, vlen,

				      flags | MSG_CMSG_COMPAT,

net/socket.c

+33 −39
Original line number Diff line number Diff line
@@ -1956,7 +1956,7 @@ struct used_address { 
	unsigned int name_len;

};



static int __sys_sendmsg(struct socket *sock, struct msghdr __user *msg,

static int ___sys_sendmsg(struct socket *sock, struct msghdr __user *msg,

			 struct msghdr *msg_sys, unsigned int flags,

			 struct used_address *used_address)

{
@@ -2071,26 +2071,30 @@ out: 
 *	BSD sendmsg interface

 */



SYSCALL_DEFINE3(sendmsg, int, fd, struct msghdr __user *, msg, unsigned int, flags)

long __sys_sendmsg(int fd, struct msghdr __user *msg, unsigned flags)

{

	int fput_needed, err;

	struct msghdr msg_sys;

	struct socket *sock;



	if (flags & MSG_CMSG_COMPAT)

		return -EINVAL;



	sock = sockfd_lookup_light(fd, &err, &fput_needed);

	if (!sock)

		goto out;



	err = __sys_sendmsg(sock, msg, &msg_sys, flags, NULL);

	err = ___sys_sendmsg(sock, msg, &msg_sys, flags, NULL);



	fput_light(sock->file, fput_needed);

out:

	return err;

}



SYSCALL_DEFINE3(sendmsg, int, fd, struct msghdr __user *, msg, unsigned int, flags)

{

	if (flags & MSG_CMSG_COMPAT)

		return -EINVAL;

	return __sys_sendmsg(fd, msg, flags);

}



/*

 *	Linux sendmmsg interface

 */
@@ -2121,14 +2125,15 @@ int __sys_sendmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen, 


	while (datagrams < vlen) {

		if (MSG_CMSG_COMPAT & flags) {

			err = __sys_sendmsg(sock, (struct msghdr __user *)compat_entry,

			err = ___sys_sendmsg(sock, (struct msghdr __user *)compat_entry,

					     &msg_sys, flags, &used_address);

			if (err < 0)

				break;

			err = __put_user(err, &compat_entry->msg_len);

			++compat_entry;

		} else {

			err = __sys_sendmsg(sock, (struct msghdr __user *)entry,

			err = ___sys_sendmsg(sock,

					     (struct msghdr __user *)entry,

					     &msg_sys, flags, &used_address);

			if (err < 0)

				break;
@@ -2158,7 +2163,7 @@ SYSCALL_DEFINE4(sendmmsg, int, fd, struct mmsghdr __user *, mmsg, 
	return __sys_sendmmsg(fd, mmsg, vlen, flags);

}



static int __sys_recvmsg(struct socket *sock, struct msghdr __user *msg,

static int ___sys_recvmsg(struct socket *sock, struct msghdr __user *msg,

			 struct msghdr *msg_sys, unsigned int flags, int nosec)

{

	struct compat_msghdr __user *msg_compat =
@@ -2250,27 +2255,31 @@ out: 
 *	BSD recvmsg interface

 */



SYSCALL_DEFINE3(recvmsg, int, fd, struct msghdr __user *, msg,

		unsigned int, flags)

long __sys_recvmsg(int fd, struct msghdr __user *msg, unsigned flags)

{

	int fput_needed, err;

	struct msghdr msg_sys;

	struct socket *sock;



	if (flags & MSG_CMSG_COMPAT)

		return -EINVAL;



	sock = sockfd_lookup_light(fd, &err, &fput_needed);

	if (!sock)

		goto out;



	err = __sys_recvmsg(sock, msg, &msg_sys, flags, 0);

	err = ___sys_recvmsg(sock, msg, &msg_sys, flags, 0);



	fput_light(sock->file, fput_needed);

out:

	return err;

}



SYSCALL_DEFINE3(recvmsg, int, fd, struct msghdr __user *, msg,

		unsigned int, flags)

{

	if (flags & MSG_CMSG_COMPAT)

		return -EINVAL;

	return __sys_recvmsg(fd, msg, flags);

}



/*

 *     Linux recvmmsg interface

 */
@@ -2308,7 +2317,7 @@ int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen, 
		 * No need to ask LSM for more than the first datagram.

		 */

		if (MSG_CMSG_COMPAT & flags) {

			err = __sys_recvmsg(sock, (struct msghdr __user *)compat_entry,

			err = ___sys_recvmsg(sock, (struct msghdr __user *)compat_entry,

					     &msg_sys, flags & ~MSG_WAITFORONE,

					     datagrams);

			if (err < 0)
@@ -2316,7 +2325,8 @@ int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen, 
			err = __put_user(err, &compat_entry->msg_len);

			++compat_entry;

		} else {

			err = __sys_recvmsg(sock, (struct msghdr __user *)entry,

			err = ___sys_recvmsg(sock,

					     (struct msghdr __user *)entry,

					     &msg_sys, flags & ~MSG_WAITFORONE,

					     datagrams);

			if (err < 0)
@@ -2505,31 +2515,15 @@ SYSCALL_DEFINE2(socketcall, int, call, unsigned long __user *, args) 
				   (int __user *)a[4]);

		break;

	case SYS_SENDMSG:

		if (a[2] & MSG_CMSG_COMPAT) {

			err = -EINVAL;

			break;

		}

		err = sys_sendmsg(a0, (struct msghdr __user *)a1, a[2]);

		break;

	case SYS_SENDMMSG:

		if (a[3] & MSG_CMSG_COMPAT) {

			err = -EINVAL;

			break;

		}

		err = sys_sendmmsg(a0, (struct mmsghdr __user *)a1, a[2], a[3]);

		break;

	case SYS_RECVMSG:

		if (a[2] & MSG_CMSG_COMPAT) {

			err = -EINVAL;

			break;

		}

		err = sys_recvmsg(a0, (struct msghdr __user *)a1, a[2]);

		break;

	case SYS_RECVMMSG:

		if (a[3] & MSG_CMSG_COMPAT) {

			err = -EINVAL;

			break;

		}

		err = sys_recvmmsg(a0, (struct mmsghdr __user *)a1, a[2], a[3],

				   (struct timespec __user *)a[4]);

		break;

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