From b269057d62756f206ec0d97a42115c7a6dd38a11 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Tue, 25 Mar 2014 11:45:20 +0100 Subject: [PATCH 02/48] qcow2: Check backing_file_offset (CVE-2014-0144) RH-Author: Kevin Wolf Message-id: <1395744364-16049-2-git-send-email-kwolf@redhat.com> Patchwork-id: n/a O-Subject: [EMBARGOED RHEL-6.6/6.5.z qemu-kvm PATCH v2 01/45] qcow2: Check backing_file_offset (CVE-2014-0144) Bugzilla: 1079453 RH-Acked-by: Max Reitz RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Jeff Cody Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1079453 Upstream status: Embargoed Header, header extension and the backing file name must all be stored in the first cluster. Setting the backing file to a much higher value allowed header extensions to become much bigger than we want them to be (unbounded allocation). Signed-off-by: Kevin Wolf Conflicts: block/qcow2.c tests/qemu-iotests/080 tests/qemu-iotests/080.out Signed-off-by: Kevin Wolf --- block/qcow2.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/block/qcow2.c b/block/qcow2.c index 71c7b23..f402cd7 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -277,6 +277,12 @@ static int qcow2_open(BlockDriverState *bs, int flags) QLIST_INIT(&s->cluster_allocs); /* read qcow2 extensions */ + if (header.backing_file_offset > s->cluster_size) { + qerror_report(QERR_GENERIC_ERROR, "Invalid backing file offset"); + ret = -EINVAL; + goto fail; + } + if (header.backing_file_offset) { ext_end = header.backing_file_offset; } else { -- 1.7.1