This is a note to let you know that I've just added the patch titled
xen/blkback: Check device permissions before allowing OP_DISCARD
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
xen-blkback-check-device-permissions-before-allowing-op_discard.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 604c499cbbcc3d5fe5fb8d53306aa0fae1990109 Mon Sep 17 00:00:00 2001
From: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Date: Wed, 16 Jan 2013 11:33:52 -0500
Subject: xen/blkback: Check device permissions before allowing OP_DISCARD
From: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
commit 604c499cbbcc3d5fe5fb8d53306aa0fae1990109 upstream.
We need to make sure that the device is not RO or that
the request is not past the number of sectors we want to
issue the DISCARD operation for.
This fixes CVE-2013-2140.
Acked-by: Jan Beulich <JBeulich@xxxxxxxx>
Acked-by: Ian Campbell <Ian.Campbell@xxxxxxxxxx>
[v1: Made it pr_warn instead of pr_debug]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/block/xen-blkback/blkback.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -399,7 +399,18 @@ static int dispatch_discard_io(struct xe
int status = BLKIF_RSP_OKAY;
struct block_device *bdev = blkif->vbd.bdev;
unsigned long secure;
+ struct phys_req preq;
+ preq.sector_number = req->u.discard.sector_number;
+ preq.nr_sects = req->u.discard.nr_sectors;
+
+ err = xen_vbd_translate(&preq, blkif, WRITE);
+ if (err) {
+ pr_warn(DRV_PFX "access denied: DISCARD [%llu->%llu] on dev=%04x\n",
+ preq.sector_number,
+ preq.sector_number + preq.nr_sects, blkif->vbd.pdevice);
+ goto fail_response;
+ }
blkif->st_ds_req++;
xen_blkif_get(blkif);
@@ -410,7 +421,7 @@ static int dispatch_discard_io(struct xe
err = blkdev_issue_discard(bdev, req->u.discard.sector_number,
req->u.discard.nr_sectors,
GFP_KERNEL, secure);
-
+fail_response:
if (err == -EOPNOTSUPP) {
pr_debug(DRV_PFX "discard op failed, not supported\n");
status = BLKIF_RSP_EOPNOTSUPP;
Patches currently in stable-queue which might be from konrad.wilk@xxxxxxxxxx are
queue-3.4/xen-blkback-check-device-permissions-before-allowing-op_discard.patch
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