From: Sven Eckelmann Date: Sat, 10 Dec 2011 14:28:36 +0000 (+0100) Subject: batman-adv: Only write requested number of byte to user buffer X-Git-Tag: firefly_0821_release~3680^2~3834^2~250^2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=b5a1eeef04cc7859f34dec9b72ea1b28e4aba07c;p=firefly-linux-kernel-4.4.55.git batman-adv: Only write requested number of byte to user buffer Don't write more than the requested number of bytes of an batman-adv icmp packet to the userspace buffer. Otherwise unrelated userspace memory might get overridden by the kernel. Signed-off-by: Sven Eckelmann Signed-off-by: Marek Lindner --- diff --git a/net/batman-adv/icmp_socket.c b/net/batman-adv/icmp_socket.c index 3b04fff3ede3..d9c1e7bb7fbf 100644 --- a/net/batman-adv/icmp_socket.c +++ b/net/batman-adv/icmp_socket.c @@ -136,10 +136,9 @@ 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); + packet_len = min(count, socket_packet->icmp_len); + error = copy_to_user(buf, &socket_packet->icmp_packet, packet_len); - packet_len = socket_packet->icmp_len; kfree(socket_packet); if (error)