batman-adv: bat_socket_read missing checks

commit c00b6856fc642b234895cfabd15b289e76726430 upstream.

Writing a icmp_packet_rr and then reading icmp_packet can lead to kernel
memory corruption, if __user *buf is just below TASK_SIZE.

Signed-off-by: Paul Kot <pawlkt@gmail.com>
[sven@narfation.org: made it checkpatch clean]
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/batman-adv/icmp_socket.c b/net/batman-adv/icmp_socket.c
index fa22ba2bb832ac97b58b4b35c36830fceb7e75ee..88c310aacc401d61d4e1391abd0e3a4eedc4622d 100644 (file)
--- a/net/batman-adv/icmp_socket.c
+++ b/net/batman-adv/icmp_socket.c
@@ -136,8 +136,8 @@ static ssize_t bat_socket_read(struct file *file, char __user *buf,
 
        spin_unlock_bh(&socket_client->lock);
 
-       error = __copy_to_user(buf, &socket_packet->icmp_packet,
-                              socket_packet->icmp_len);
+       error = copy_to_user(buf, &socket_packet->icmp_packet,
+                            socket_packet->icmp_len);
 
        packet_len = socket_packet->icmp_len;
        kfree(socket_packet);