From 9302e863aa8baa5d932fc078967050c055fa1a7f Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Wed, 26 Mar 2014 13:06:09 +0100 Subject: parallels: Sanity check for s->tracks (CVE-2014-0142) This avoids a possible division by zero. Convert s->tracks to unsigned as well because it feels better than surviving just because the results of calculations with s->tracks are converted to unsigned anyway. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Signed-off-by: Stefan Hajnoczi --- block/parallels.c | 7 ++++++- tests/qemu-iotests/076 | 7 +++++++ tests/qemu-iotests/076.out | 4 ++++ 3 files changed, 17 insertions(+), 1 deletion(-) diff --git a/block/parallels.c b/block/parallels.c index fe47ecb..1a5bd35 100644 --- a/block/parallels.c +++ b/block/parallels.c @@ -51,7 +51,7 @@ typedef struct BDRVParallelsState { uint32_t *catalog_bitmap; unsigned int catalog_size; - int tracks; + unsigned int tracks; } BDRVParallelsState; static int parallels_probe(const uint8_t *buf, int buf_size, const char *filename) @@ -93,6 +93,11 @@ static int parallels_open(BlockDriverState *bs, QDict *options, int flags, bs->total_sectors = le32_to_cpu(ph.nb_sectors); s->tracks = le32_to_cpu(ph.tracks); + if (s->tracks == 0) { + error_setg(errp, "Invalid image: Zero sectors per track"); + ret = -EINVAL; + goto fail; + } s->catalog_size = le32_to_cpu(ph.catalog_entries); if (s->catalog_size > INT_MAX / 4) { diff --git a/tests/qemu-iotests/076 b/tests/qemu-iotests/076 index 6028ac5..b614a7d 100755 --- a/tests/qemu-iotests/076 +++ b/tests/qemu-iotests/076 @@ -42,6 +42,7 @@ _supported_fmt parallels _supported_proto generic _supported_os Linux +tracks_offset=$((0x1c)) catalog_entries_offset=$((0x20)) nb_sectors_offset=$((0x24)) @@ -63,6 +64,12 @@ poke_file "$TEST_IMG" "$nb_sectors_offset" "\xff\xff\xff\xff" poke_file "$TEST_IMG" "$catalog_entries_offset" "\x01\x00\x00\x40" { $QEMU_IO -c "read 64M 64M" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir +echo +echo "== Zero sectors per track ==" +_use_sample_img fake.parallels.bz2 +poke_file "$TEST_IMG" "$tracks_offset" "\x00\x00\x00\x00" +{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir + # success, all done echo "*** done" rm -f $seq.full diff --git a/tests/qemu-iotests/076.out b/tests/qemu-iotests/076.out index 12af42a..f7745d8 100644 --- a/tests/qemu-iotests/076.out +++ b/tests/qemu-iotests/076.out @@ -11,4 +11,8 @@ no file open, try 'help open' == Overflow in catalog allocation == qemu-io: can't open device TEST_DIR/fake.parallels: Catalog too large no file open, try 'help open' + +== Zero sectors per track == +qemu-io: can't open device TEST_DIR/fake.parallels: Invalid image: Zero sectors per track +no file open, try 'help open' *** done -- cgit v1.1