From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754746Ab1AFAim (ORCPT ); Wed, 5 Jan 2011 19:38:42 -0500 Received: from kroah.org ([198.145.64.141]:36020 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754667Ab1AFAbX (ORCPT ); Wed, 5 Jan 2011 19:31:23 -0500 X-Mailbox-Line: From gregkh@clark.site Wed Jan 5 16:23:08 2011 Message-Id: <20110106002308.241538197@clark.site> User-Agent: quilt/0.48-11.2 Date: Wed, 05 Jan 2011 16:23:41 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, "Ahmed S. Darwish" , Marco Stornelli Subject: [122/152] RAMOOPS: Dont overflow over non-allocated regions In-Reply-To: <20110106002500.GA3172@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.36-stable review patch. If anyone has any objections, please let us know. ------------------ From: Ahmed S. Darwish commit 1873bb8115e678ad9fd0aac9dbbc68383bc36e06 upstream. The current code mis-calculates the ramoops header size, leading to an overflow over the next record at best, or over a non-allocated region at worst. Fix that calculation. Signed-off-by: Ahmed S. Darwish Acked-by: Marco Stornelli Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/char/ramoops.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) --- a/drivers/char/ramoops.c +++ b/drivers/char/ramoops.c @@ -27,7 +27,6 @@ #include #define RAMOOPS_KERNMSG_HDR "====" -#define RAMOOPS_HEADER_SIZE (5 + sizeof(struct timeval)) #define RECORD_SIZE 4096 @@ -63,8 +62,8 @@ static void ramoops_do_dump(struct kmsg_ struct ramoops_context, dump); unsigned long s1_start, s2_start; unsigned long l1_cpy, l2_cpy; - int res; - char *buf; + int res, hdr_size; + char *buf, *buf_orig; struct timeval timestamp; /* Only dump oopses if dump_oops is set */ @@ -72,6 +71,8 @@ static void ramoops_do_dump(struct kmsg_ return; buf = (char *)(cxt->virt_addr + (cxt->count * RECORD_SIZE)); + buf_orig = buf; + memset(buf, '\0', RECORD_SIZE); res = sprintf(buf, "%s", RAMOOPS_KERNMSG_HDR); buf += res; @@ -79,8 +80,9 @@ static void ramoops_do_dump(struct kmsg_ res = sprintf(buf, "%lu.%lu\n", (long)timestamp.tv_sec, (long)timestamp.tv_usec); buf += res; - l2_cpy = min(l2, (unsigned long)(RECORD_SIZE - RAMOOPS_HEADER_SIZE)); - l1_cpy = min(l1, (unsigned long)(RECORD_SIZE - RAMOOPS_HEADER_SIZE) - l2_cpy); + hdr_size = buf - buf_orig; + l2_cpy = min(l2, (unsigned long)(RECORD_SIZE - hdr_size)); + l1_cpy = min(l1, (unsigned long)(RECORD_SIZE - hdr_size) - l2_cpy); s2_start = l2 - l2_cpy; s1_start = l1 - l1_cpy;