diff options
| author | Kevin Wolf <kwolf@redhat.com> | 2014-03-26 13:06:04 +0100 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2014-04-01 15:22:35 +0200 |
| commit | 11b128f4062dd7f89b14abc8877ff20d41b28be9 (patch) | |
| tree | dbbe66c763e4fd486d13703617ba092e7e7437e6 | |
| parent | 6b7d4c55586a849aa8313282d79432917eade3bf (diff) | |
| download | qemu-11b128f4062dd7f89b14abc8877ff20d41b28be9.zip qemu-11b128f4062dd7f89b14abc8877ff20d41b28be9.tar.gz qemu-11b128f4062dd7f89b14abc8877ff20d41b28be9.tar.bz2 | |
qcow2: Fix NULL dereference in qcow2_open() error path (CVE-2014-0146)
The qcow2 code assumes that s->snapshots is non-NULL if s->nb_snapshots
!= 0. By having the initialisation of both fields separated in
qcow2_open(), any error occuring in between would cause the error path
to dereference NULL in qcow2_free_snapshots() if the image had any
snapshots.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
| -rw-r--r-- | block/qcow2.c | 7 | ||||
| -rwxr-xr-x | tests/qemu-iotests/080 | 7 | ||||
| -rw-r--r-- | tests/qemu-iotests/080.out | 4 |
3 files changed, 15 insertions, 3 deletions
diff --git a/block/qcow2.c b/block/qcow2.c index b64564d..be48a27 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -637,9 +637,6 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, goto fail; } - s->snapshots_offset = header.snapshots_offset; - s->nb_snapshots = header.nb_snapshots; - /* read the level 1 table */ if (header.l1_size > 0x2000000) { /* 32 MB L1 table is enough for 2 PB images at 64k cluster size @@ -734,6 +731,10 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, bs->backing_file[len] = '\0'; } + /* Internal snapshots */ + s->snapshots_offset = header.snapshots_offset; + s->nb_snapshots = header.nb_snapshots; + ret = qcow2_read_snapshots(bs); if (ret < 0) { error_setg_errno(errp, -ret, "Could not read snapshots"); diff --git a/tests/qemu-iotests/080 b/tests/qemu-iotests/080 index 56f8903..59e7a44 100755 --- a/tests/qemu-iotests/080 +++ b/tests/qemu-iotests/080 @@ -139,6 +139,13 @@ poke_file "$TEST_IMG" "$offset_l1_size" "\x00\x00\x00\x01" { $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir echo +echo "== Invalid L1 table (with internal snapshot in the image) ==" +_make_test_img 64M +{ $QEMU_IMG snapshot -c foo $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir +poke_file "$TEST_IMG" "$offset_l1_size" "\x00\x00\x00\x00" +_img_info + +echo echo "== Invalid backing file size ==" _make_test_img 64M poke_file "$TEST_IMG" "$offset_backing_file_offset" "\x00\x00\x00\x00\x00\x00\x10\x00" diff --git a/tests/qemu-iotests/080.out b/tests/qemu-iotests/080.out index 303d6c3..4d84fbf 100644 --- a/tests/qemu-iotests/080.out +++ b/tests/qemu-iotests/080.out @@ -59,6 +59,10 @@ no file open, try 'help open' qemu-io: can't open device TEST_DIR/t.qcow2: Invalid L1 table offset no file open, try 'help open' +== Invalid L1 table (with internal snapshot in the image) == +Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 +qemu-img: Could not open 'TEST_DIR/t.IMGFMT': L1 table is too small + == Invalid backing file size == Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 qemu-io: can't open device TEST_DIR/t.qcow2: Backing file name too long |