From 42eb58179b3b215bb507da3262b682b8a2ec10b5 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 15 May 2014 16:10:11 +0200 Subject: qcow1: Validate L2 table size (CVE-2014-0222) Too large L2 table sizes cause unbounded allocations. Images actually created by qemu-img only have 512 byte or 4k L2 tables. To keep things consistent with cluster sizes, allow ranges between 512 bytes and 64k (in fact, down to 1 entry = 8 bytes is technically working, but L2 table sizes smaller than a cluster don't make a lot of sense). This also means that the number of bytes on the virtual disk that are described by the same L2 table is limited to at most 8k * 64k or 2^29, preventively avoiding any integer overflows. Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf Reviewed-by: Benoit Canet --- tests/qemu-iotests/092.out | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'tests/qemu-iotests/092.out') diff --git a/tests/qemu-iotests/092.out b/tests/qemu-iotests/092.out index 8bf81580cd..73918b3c50 100644 --- a/tests/qemu-iotests/092.out +++ b/tests/qemu-iotests/092.out @@ -10,4 +10,15 @@ qemu-io: can't open device TEST_DIR/t.qcow: Cluster size must be between 512 and no file open, try 'help open' qemu-io: can't open device TEST_DIR/t.qcow: Cluster size must be between 512 and 64k no file open, try 'help open' + +== Invalid L2 table size == +Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 +qemu-io: can't open device TEST_DIR/t.qcow: L2 table size must be between 512 and 64k +no file open, try 'help open' +qemu-io: can't open device TEST_DIR/t.qcow: L2 table size must be between 512 and 64k +no file open, try 'help open' +qemu-io: can't open device TEST_DIR/t.qcow: L2 table size must be between 512 and 64k +no file open, try 'help open' +qemu-io: can't open device TEST_DIR/t.qcow: L2 table size must be between 512 and 64k +no file open, try 'help open' *** done -- cgit v1.2.3