From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sven Eckelmann , Marek Lindner , Jiri Slaby Subject: [ 22/56] batman-adv: Only write requested number of byte to user buffer Date: Tue, 2 Apr 2013 15:49:49 -0700 Message-Id: <20130402224714.460411537@linuxfoundation.org> In-Reply-To: <20130402224711.840825715@linuxfoundation.org> References: <20130402224711.840825715@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sven Eckelmann 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(-) --- 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 fi 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)