@@ -399,7 +399,18 @@ static int dispatch_discard_io(struct xen_blkif *blkif,
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 xen_blkif *blkif,
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;
This is a note to let you know that I have just added a patch titled xen/blkback: Check device permissions before allowing to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From bf12f3831a7cd624fbcc711d354ae58f63233c0f Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Date: Wed, 16 Jan 2013 11:33:52 -0500 Subject: [PATCH] xen/blkback: Check device permissions before allowing OP_DISCARD 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@suse.com> Acked-by: Ian Campbell <Ian.Campbell@citrix.com> [v1: Made it pr_warn instead of pr_debug] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/block/xen-blkback/blkback.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) -- 1.8.1.2