From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from einhorn.in-berlin.de ([192.109.42.8]:47760 "EHLO einhorn.in-berlin.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753741AbaIHMVj (ORCPT ); Mon, 8 Sep 2014 08:21:39 -0400 Date: Mon, 8 Sep 2014 14:05:02 +0200 From: Stefan Richter To: Dan Carpenter , Mauro Carvalho Chehab Cc: linux-media@vger.kernel.org, linux1394-devel@lists.sourceforge.net, kernel-janitors@vger.kernel.org Subject: Re: [patch] [media] firewire: firedtv-avc: potential buffer overflow Message-ID: <20140908140502.20d6f864@kant> In-Reply-To: <20140908111843.GC6947@mwanda> References: <20140908111843.GC6947@mwanda> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On Sep 08 Dan Carpenter wrote: > "program_info_length" is user controlled and can go up to 4095. The > operand[] array has 509 bytes so we need to add a limit here to prevent > buffer overflows. > > Signed-off-by: Dan Carpenter Reviewed-by: Stefan Richter Thank you. > > diff --git a/drivers/media/firewire/firedtv-avc.c b/drivers/media/firewire/firedtv-avc.c > index d1a1a13..ac17567 100644 > --- a/drivers/media/firewire/firedtv-avc.c > +++ b/drivers/media/firewire/firedtv-avc.c > @@ -1157,6 +1157,10 @@ int avc_ca_pmt(struct firedtv *fdtv, char *msg, int length) > if (pmt_cmd_id != 1 && pmt_cmd_id != 4) > dev_err(fdtv->device, > "invalid pmt_cmd_id %d\n", pmt_cmd_id); > + if (program_info_length > sizeof(c->operand) - write_pos) { > + ret = -EINVAL; > + goto out; > + } > > memcpy(&c->operand[write_pos], &msg[read_pos], > program_info_length); > @@ -1180,6 +1184,11 @@ int avc_ca_pmt(struct firedtv *fdtv, char *msg, int length) > dev_err(fdtv->device, "invalid pmt_cmd_id %d " > "at stream level\n", pmt_cmd_id); > > + if (es_info_length > sizeof(c->operand) - write_pos) { > + ret = -EINVAL; > + goto out; > + } > + > memcpy(&c->operand[write_pos], &msg[read_pos], > es_info_length); > read_pos += es_info_length; -- Stefan Richter -=====-====- =--= -=--- http://arcgraph.de/sr/