Commit 016a266b authored by Al Viro's avatar Al Viro Committed by David S. Miller
Browse files

socketpair(): allocate descriptors first 



simplifies failure exits considerably...

Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a5739435

net/socket.c

+38 −51
Original line number Diff line number Diff line
@@ -1365,88 +1365,75 @@ SYSCALL_DEFINE4(socketpair, int, family, int, type, int, protocol, 
	if (SOCK_NONBLOCK != O_NONBLOCK && (flags & SOCK_NONBLOCK))

		flags = (flags & ~SOCK_NONBLOCK) | O_NONBLOCK;



	/*

	 * reserve descriptors and make sure we won't fail

	 * to return them to userland.

	 */

	fd1 = get_unused_fd_flags(flags);

	if (unlikely(fd1 < 0))

		return fd1;



	fd2 = get_unused_fd_flags(flags);

	if (unlikely(fd2 < 0)) {

		put_unused_fd(fd1);

		return fd2;

	}



	err = put_user(fd1, &usockvec[0]);

	if (err)

		goto out;



	err = put_user(fd2, &usockvec[1]);

	if (err)

		goto out;



	/*

	 * Obtain the first socket and check if the underlying protocol

	 * supports the socketpair call.

	 */



	err = sock_create(family, type, protocol, &sock1);

	if (err < 0)

	if (unlikely(err < 0))

		goto out;



	err = sock_create(family, type, protocol, &sock2);

	if (err < 0)

		goto out_release_1;



	err = sock1->ops->socketpair(sock1, sock2);

	if (err < 0)

		goto out_release_both;



	fd1 = get_unused_fd_flags(flags);

	if (unlikely(fd1 < 0)) {

		err = fd1;

		goto out_release_both;

	if (unlikely(err < 0)) {

		sock_release(sock1);

		goto out;

	}



	fd2 = get_unused_fd_flags(flags);

	if (unlikely(fd2 < 0)) {

		err = fd2;

		goto out_put_unused_1;

	err = sock1->ops->socketpair(sock1, sock2);

	if (unlikely(err < 0)) {

		sock_release(sock2);

		sock_release(sock1);

		goto out;

	}



	newfile1 = sock_alloc_file(sock1, flags, NULL);

	if (IS_ERR(newfile1)) {

		err = PTR_ERR(newfile1);

		goto out_put_unused_both;

		sock_release(sock1);

		sock_release(sock2);

		goto out;

	}



	newfile2 = sock_alloc_file(sock2, flags, NULL);

	if (IS_ERR(newfile2)) {

		err = PTR_ERR(newfile2);

		goto out_fput_1;

		sock_release(sock2);

		fput(newfile1);

		goto out;

	}



	err = put_user(fd1, &usockvec[0]);

	if (err)

		goto out_fput_both;



	err = put_user(fd2, &usockvec[1]);

	if (err)

		goto out_fput_both;



	audit_fd_pair(fd1, fd2);



	fd_install(fd1, newfile1);

	fd_install(fd2, newfile2);

	/* fd1 and fd2 may be already another descriptors.

	 * Not kernel problem.

	 */



	return 0;



out_fput_both:

	fput(newfile2);

	fput(newfile1);

	put_unused_fd(fd2);

	put_unused_fd(fd1);

	goto out;



out_fput_1:

	fput(newfile1);

	put_unused_fd(fd2);

	put_unused_fd(fd1);

	sock_release(sock2);

	goto out;



out_put_unused_both:

out:

	put_unused_fd(fd2);

out_put_unused_1:

	put_unused_fd(fd1);

out_release_both:

	sock_release(sock2);

out_release_1:

	sock_release(sock1);

out:

	return err;

}