qcow2: Check backing_file_offset (CVE-2014-0144)
Header, header extension and the backing file name must all be stored in
the first cluster. Setting the backing file to a much higher value
allowed header extensions to become much bigger than we want them to be
(unbounded allocation).
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/tests/qemu-iotests/080.out b/tests/qemu-iotests/080.out
index 41a166a..48c40aa 100644
--- a/tests/qemu-iotests/080.out
+++ b/tests/qemu-iotests/080.out
@@ -6,4 +6,11 @@
no file open, try 'help open'
qemu-io: can't open device TEST_DIR/t.qcow2: qcow2 header exceeds cluster size
no file open, try 'help open'
+
+== Huge unknown header extension ==
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+qemu-io: can't open device TEST_DIR/t.qcow2: Invalid backing file offset
+no file open, try 'help open'
+qemu-io: can't open device TEST_DIR/t.qcow2: Header extension too large
+no file open, try 'help open'
*** done
