From 948c73284248032b7b915147c4c5ca1b3324cbab Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Tue, 3 Jun 2014 10:01:33 +0200
Subject: [PATCH 14/26] qcow1: Validate image size (CVE-2014-0223)
RH-Author: Kevin Wolf <kwolf@redhat.com>
Message-id: <1401789694-14289-6-git-send-email-kwolf@redhat.com>
Patchwork-id: 59111
O-Subject: [RHEL-6.6/6.5.z qemu-kvm PATCH 5/6] qcow1: Validate image size (CVE-2014-0223)
Bugzilla: 1097235
RH-Acked-by: Max Reitz <mreitz@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1097235
A huge image size could cause s->l1_size to overflow. Make sure that
images never require a L1 table larger than what fits in s->l1_size.
This cannot only cause unbounded allocations, but also the allocation of
a too small L1 table, resulting in out-of-bounds array accesses (both
reads and writes).
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit 46485de0cb357b57373e1ca895adedf1f3ed46ec)
Conflicts:
tests/qemu-iotests/092
tests/qemu-iotests/092.out
Replaced error_setg() by qerror_report() for RHEL 6.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
block/qcow.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
block/qcow.c | 16 ++++++++++++++--
1 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/block/qcow.c b/block/qcow.c
index 9c372ff..e6ba2c9 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -60,7 +60,7 @@ typedef struct BDRVQcowState {
int cluster_sectors;
int l2_bits;
int l2_size;
- int l1_size;
+ unsigned int l1_size;
uint64_t cluster_offset_mask;
uint64_t l1_table_offset;
uint64_t *l1_table;
@@ -163,7 +163,19 @@ static int qcow_open(BlockDriverState *bs, int flags)
/* read the level 1 table */
shift = s->cluster_bits + s->l2_bits;
- s->l1_size = (header.size + (1LL << shift) - 1) >> shift;
+ if (header.size > UINT64_MAX - (1LL << shift)) {
+ qerror_report(QERR_GENERIC_ERROR, "Image too large");
+ ret = -EINVAL;
+ goto fail;
+ } else {
+ uint64_t l1_size = (header.size + (1LL << shift) - 1) >> shift;
+ if (l1_size > INT_MAX / sizeof(uint64_t)) {
+ qerror_report(QERR_GENERIC_ERROR, "Image too large");
+ ret = -EINVAL;
+ goto fail;
+ }
+ s->l1_size = l1_size;
+ }
s->l1_table_offset = header.l1_table_offset;
s->l1_table = g_malloc(s->l1_size * sizeof(uint64_t));
--
1.7.1