net: validate the range we feed to iov_iter_init() in sys_sendto/sys_recvfrom

Cc: stable@vger.kernel.org # v3.19
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/socket.c b/net/socket.c
index bbedbfc..245330c 100644 (file)
--- a/net/socket.c
+++ b/net/socket.c
@@ -1702,6 +1702,8 @@ SYSCALL_DEFINE6(sendto, int, fd, void __user *, buff, size_t, len,
 
        if (len > INT_MAX)
                len = INT_MAX;
+       if (unlikely(!access_ok(VERIFY_READ, buff, len)))
+               return -EFAULT;
        sock = sockfd_lookup_light(fd, &err, &fput_needed);
        if (!sock)
                goto out;
@@ -1760,6 +1762,8 @@ SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, ubuf, size_t, size,
 
        if (size > INT_MAX)
                size = INT_MAX;
+       if (unlikely(!access_ok(VERIFY_WRITE, ubuf, size)))
+               return -EFAULT;
        sock = sockfd_lookup_light(fd, &err, &fput_needed);
        if (!sock)
                goto out;