tree ab604a42d397957a3aeb55c343d59648d6332c30
parent 7c4d7d710f7eb499ec483f25acc28b53adaa3260
author Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> 1358354032 -0500
committer Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> 1370639155 -0400

xen/blkback: Check device permissions before allowing OP_DISCARD

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.

Cc: stable@vger.kernel.org
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>