From 2e8e2c7847cc17a8135ad17869f5ba37207e2f89 Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Tue, 19 Mar 2013 12:36:50 +0100 Subject: [PATCH] batman-adv: Only write requested number of byte to user buffer commit b5a1eeef04cc7859f34dec9b72ea1b28e4aba07c upstream. 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 Signed-off-by: Jiri Slaby Signed-off-by: Greg Kroah-Hartman --- net/batman-adv/icmp_socket.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/net/batman-adv/icmp_socket.c b/net/batman-adv/icmp_socket.c index 88c310aacc40..ad7d8b289abd 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) -- 2.39.5