Insanely large requests could cause an integer overflow in
bdrv_rw_co() while converting sectors to bytes. This patch catches the
problem and returns an error (if we hadn't overflown the integer here,
bdrv_check_byte_request() would have rejected the request, so we're not
breaking anything that was supposed to work before).
We actually do have a test case that triggers behaviour where we
accidentally let such a request pass, so that it would return success,
but read 0 bytes instead of the requested 4 GB. It fails now like it
should.
If the vdi block driver wants to be able to deal with huge images, it
can't read the whole block bitmap at once into memory like it does
today, but needs to use a metadata cache like qcow2 does.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This test checks for proper bounds checking of some VDI input
headers. The following is checked:
1. Max image size (1024TB) with the appropriate Blocks In Image
value (0x3fffffff) is detected as valid.
2. Image size exceeding max (1024TB) is seen as invalid
3. Valid image size but with Blocks In Image value that is too
small fails
4. Blocks In Image size exceeding max (0x3fffffff) is seen as invalid
5. 64MB image, with 64 Blocks In Image, and 1MB Block Size is seen
as valid
6. Block Size < 1MB not supported
7. Block Size > 1MB not supported
[Max Reitz <mreitz@redhat.com> pointed out that "1MB + 1" in the test
case is wrong. Change to "1MB + 64KB" to match the 0x110000 value.
--Stefan]
Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
