FAQ Search Today's Posts Mark Forums Read
» Video Reviews

» Linux Archive

Linux-archive is a website aiming to archive linux email lists and to make them easily accessible for linux users/developers.


» Sponsor

» Partners

» Sponsor

Go Back   Linux Archive > Ubuntu > Ubuntu Kernel Team

 
 
LinkBack Thread Tools
 
Old 10-28-2010, 03:40 PM
Linus Torvalds
 
Default net: fix rds_iovec page count overflow

BugLink: http://bugs.launchpad.net/bugs/709153
CVE-2010-3865

As reported by Thomas Pollet, the rdma page counting can overflow. We
get the rdma sizes in 64-bit unsigned entities, but then limit it to
UINT_MAX bytes and shift them down to pages (so with a possible "+1" for
an unaligned address).

So each individual page count fits comfortably in an 'unsigned int' (not
even close to overflowing into signed), but as they are added up, they
might end up resulting in a signed return value. Which would be wrong.

Catch the case of tot_pages turning negative, and return the appropriate
error code.

Reported-by: Thomas Pollet <thomas.pollet@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(backported from commit 1b1f693d7ad6d193862dcb1118540a030c5e761f upstream)
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
---
net/rds/rdma.c | 10 ++++++++++
1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/net/rds/rdma.c b/net/rds/rdma.c
index 3998967..0a403a7 100644
--- a/net/rds/rdma.c
+++ b/net/rds/rdma.c
@@ -500,6 +500,16 @@ static struct rds_rdma_op *rds_rdma_prepare(struct rds_sock *rs,

max_pages = max(nr, max_pages);
nr_pages += nr;
+
+ /*
+ * nr for one entry in limited to (UINT_MAX>>PAGE_SHIFT)+1
+ * so nr_pages cannot overflow without first going negative.
+ * If nr cannot overflow then max_pages should be ok.
+ */
+ if (nr_pages < 0) {
+ ret = -EINVAL;
+ goto out;
+ }
}

pages = kcalloc(max_pages, sizeof(struct page *), GFP_KERNEL);
--
1.7.0.4


--
kernel-team mailing list
kernel-team@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/kernel-team
 
Old 10-28-2010, 03:40 PM
Linus Torvalds
 
Default net: fix rds_iovec page count overflow

BugLink: http://bugs.launchpad.net/bugs/709153
CVE-2010-3865

As reported by Thomas Pollet, the rdma page counting can overflow. We
get the rdma sizes in 64-bit unsigned entities, but then limit it to
UINT_MAX bytes and shift them down to pages (so with a possible "+1" for
an unaligned address).

So each individual page count fits comfortably in an 'unsigned int' (not
even close to overflowing into signed), but as they are added up, they
might end up resulting in a signed return value. Which would be wrong.

Catch the case of tot_pages turning negative, and return the appropriate
error code.

Reported-by: Thomas Pollet <thomas.pollet@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(backported from commit 1b1f693d7ad6d193862dcb1118540a030c5e761f upstream)
[v2: nr is unsigned in the old code]
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
---
net/rds/rdma.c | 11 +++++++++++
1 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/net/rds/rdma.c b/net/rds/rdma.c
index 6b09b94..ff5e3c9 100644
--- a/net/rds/rdma.c
+++ b/net/rds/rdma.c
@@ -473,6 +473,17 @@ static struct rds_rdma_op *rds_rdma_prepare(struct rds_sock *rs,

max_pages = max(nr, max_pages);
nr_pages += nr;
+
+ /*
+ * nr for one entry in limited to (UINT_MAX>>PAGE_SHIFT)+1
+ * so nr_pages cannot overflow without becoming bigger than
+ * INT_MAX first. If nr cannot overflow then max_pages should
+ * be ok.
+ */
+ if (nr_pages > INT_MAX) {
+ ret = -EINVAL;
+ goto out;
+ }
}

pages = kcalloc(max_pages, sizeof(struct page *), GFP_KERNEL);
--
1.7.0.4


--------------060104000902000801090001
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

--
kernel-team mailing list
kernel-team@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/kernel-team

--------------060104000902000801090001--
 

Thread Tools




All times are GMT. The time now is 09:42 PM.

VBulletin, Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO ©2007, Crawlability, Inc.
Copyright 2007 - 2008, www.linux-archive.org