thebeanogamer / rpms / qemu-kvm

Forked from rpms/qemu-kvm 5 months ago
Clone
9ae3a8
From 4ce3cdbea5f0006ec857767f2dc74a02fffd0cb5 Mon Sep 17 00:00:00 2001
9ae3a8
From: Kevin Wolf <kwolf@redhat.com>
9ae3a8
Date: Tue, 25 Mar 2014 14:23:50 +0100
9ae3a8
Subject: [PATCH 43/49] qcow2: Fix NULL dereference in qcow2_open() error path (CVE-2014-0146)
9ae3a8
9ae3a8
RH-Author: Kevin Wolf <kwolf@redhat.com>
9ae3a8
Message-id: <1395753835-7591-44-git-send-email-kwolf@redhat.com>
9ae3a8
Patchwork-id: n/a
9ae3a8
O-Subject: [virt-devel] [EMBARGOED RHEL-7.0 qemu-kvm PATCH 43/48] qcow2: Fix NULL dereference in qcow2_open() error path (CVE-2014-0146)
9ae3a8
Bugzilla: 1079333
9ae3a8
RH-Acked-by: Jeff Cody <jcody@redhat.com>
9ae3a8
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
9ae3a8
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
9ae3a8
9ae3a8
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1079333
9ae3a8
Upstream status: Embargoed
9ae3a8
9ae3a8
The qcow2 code assumes that s->snapshots is non-NULL if s->nb_snapshots
9ae3a8
!= 0. By having the initialisation of both fields separated in
9ae3a8
qcow2_open(), any error occuring in between would cause the error path
9ae3a8
to dereference NULL in qcow2_free_snapshots() if the image had any
9ae3a8
snapshots.
9ae3a8
9ae3a8
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
9ae3a8
---
9ae3a8
 block/qcow2.c              |    7 ++++---
9ae3a8
 tests/qemu-iotests/080     |    7 +++++++
9ae3a8
 tests/qemu-iotests/080.out |    4 ++++
9ae3a8
 3 files changed, 15 insertions(+), 3 deletions(-)
9ae3a8
9ae3a8
diff --git a/block/qcow2.c b/block/qcow2.c
9ae3a8
index db9f667..33b46b8 100644
9ae3a8
--- a/block/qcow2.c
9ae3a8
+++ b/block/qcow2.c
9ae3a8
@@ -636,9 +636,6 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,
9ae3a8
         goto fail;
9ae3a8
     }
9ae3a8
 
9ae3a8
-    s->snapshots_offset = header.snapshots_offset;
9ae3a8
-    s->nb_snapshots = header.nb_snapshots;
9ae3a8
-
9ae3a8
     /* read the level 1 table */
9ae3a8
     if (header.l1_size > 0x2000000) {
9ae3a8
         /* 32 MB L1 table is enough for 2 PB images at 64k cluster size
9ae3a8
@@ -733,6 +730,10 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,
9ae3a8
         bs->backing_file[len] = '\0';
9ae3a8
     }
9ae3a8
 
9ae3a8
+    /* Internal snapshots */
9ae3a8
+    s->snapshots_offset = header.snapshots_offset;
9ae3a8
+    s->nb_snapshots = header.nb_snapshots;
9ae3a8
+
9ae3a8
     ret = qcow2_read_snapshots(bs);
9ae3a8
     if (ret < 0) {
9ae3a8
         error_setg_errno(errp, -ret, "Could not read snapshots");
9ae3a8
diff --git a/tests/qemu-iotests/080 b/tests/qemu-iotests/080
9ae3a8
index 56f8903..59e7a44 100755
9ae3a8
--- a/tests/qemu-iotests/080
9ae3a8
+++ b/tests/qemu-iotests/080
9ae3a8
@@ -139,6 +139,13 @@ poke_file "$TEST_IMG" "$offset_l1_size" "\x00\x00\x00\x01"
9ae3a8
 { $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir
9ae3a8
 
9ae3a8
 echo
9ae3a8
+echo "== Invalid L1 table (with internal snapshot in the image) =="
9ae3a8
+_make_test_img 64M
9ae3a8
+{ $QEMU_IMG snapshot -c foo $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir
9ae3a8
+poke_file "$TEST_IMG" "$offset_l1_size" "\x00\x00\x00\x00"
9ae3a8
+_img_info
9ae3a8
+
9ae3a8
+echo
9ae3a8
 echo "== Invalid backing file size =="
9ae3a8
 _make_test_img 64M
9ae3a8
 poke_file "$TEST_IMG" "$offset_backing_file_offset" "\x00\x00\x00\x00\x00\x00\x10\x00"
9ae3a8
diff --git a/tests/qemu-iotests/080.out b/tests/qemu-iotests/080.out
9ae3a8
index 303d6c3..4d84fbf 100644
9ae3a8
--- a/tests/qemu-iotests/080.out
9ae3a8
+++ b/tests/qemu-iotests/080.out
9ae3a8
@@ -59,6 +59,10 @@ no file open, try 'help open'
9ae3a8
 qemu-io: can't open device TEST_DIR/t.qcow2: Invalid L1 table offset
9ae3a8
 no file open, try 'help open'
9ae3a8
 
9ae3a8
+== Invalid L1 table (with internal snapshot in the image) ==
9ae3a8
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 
9ae3a8
+qemu-img: Could not open 'TEST_DIR/t.IMGFMT': L1 table is too small
9ae3a8
+
9ae3a8
 == Invalid backing file size ==
9ae3a8
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 
9ae3a8
 qemu-io: can't open device TEST_DIR/t.qcow2: Backing file name too long
9ae3a8
-- 
9ae3a8
1.7.1
9ae3a8