Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752768Ab3CRErQ (ORCPT ); Mon, 18 Mar 2013 00:47:16 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33447 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751651Ab3CREaU (ORCPT ); Mon, 18 Mar 2013 00:30:20 -0400 Message-Id: <20130318042151.545639263@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Mon, 18 Mar 2013 04:22:59 +0000 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, Sven Eckelmann , Marek Lindner Subject: [ 75/82] batman-adv: Only write requested number of byte to user buffer In-Reply-To: <20130318042144.234468645@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:d98f:da4e:f620:7bea X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1350 Lines: 41 3.2-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: Ben Hutchings --- 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) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/