Hardy CVE-2010-4163: block: check for proper length of iov entries earlier in blk_rq_map_user_iov()

Tim Gardner timg at tpi.com
Fri Feb 18 21:18:14 UTC 2011


The following changes since commit 0b2f210442dd2ca2c184c1451f5d41fa37e7c60b:
  Brad Figg (1):
        UBUNTU: Ubuntu-2.6.24-28.86

are available in the git repository at:

  git://kernel.ubuntu.com/rtg/ubuntu-hardy.git CVE-2010-4163

Tim Gardner (1):
      block: check for proper length of iov entries earlier in blk_rq_map_user_iov(), CVE-2010-4163

 fs/bio.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

>From aabab832c692067d4558aa577222ee408be06df0 Mon Sep 17 00:00:00 2001
From: Tim Gardner <tim.gardner at canonical.com>
Date: Fri, 18 Feb 2011 14:15:10 -0700
Subject: [PATCH] block: check for proper length of iov entries earlier in blk_rq_map_user_iov(), CVE-2010-4163

BugLink: http://bugs.launchpad.net/bugs/721504

CVE-2010-4163

commit 9284bcf checks for proper length of iov entries in
blk_rq_map_user_iov(). But if the map is unaligned, kernel
will break out the loop without checking for the proper length.
So we need to check the proper length before the unalign check.

Signed-off-by: Xiaotian Feng <dfeng at redhat.com>
Cc: stable at kernel.org
Signed-off-by: Jens Axboe <jaxboe at fusionio.com>
(backported from commit 5478755616ae2ef1ce144dded589b62b2a50d575)

Signed-off-by: Tim Gardner <tim.gardner at canonical.com>
---
 fs/bio.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/fs/bio.c b/fs/bio.c
index d59ddbf..461ca55 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -609,6 +609,9 @@ static struct bio *__bio_map_user_iov(struct request_queue *q,
 		unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
 		unsigned long start = uaddr >> PAGE_SHIFT;
 
+		if (!len)
+			return ERR_PTR(-EINVAL);
+
 		nr_pages += end - start;
 		/*
 		 * buffer must be aligned to at least hardsector size for now
-- 
1.7.0.4





More information about the kernel-team mailing list