Re: [Qemu-devel] [PATCH] block/vmdk: Report failures in vmdk_read_cid()

[Kevin Wolf <kwolf@redhat.com>]

Am 09.07.2017 um 19:06 hat Peter Maydell geschrieben:
> The function vmdk_read_cid() can fail if the read on the underlying
> block device fails, or if there's a format error in the VMDK file.
> However its API doesn't provide a mechanism to report these errors,
> and in some cases we were returning a CID of 0 and in some cases a
> CID of 0xffffffff, either of which might potentially be valid values.
> 
> Change the function to return 0 on success or a negative errno, and
> return the CID via a uint32_t* argument. Update the callsites to
> handle and propagate the error appropriately.
> 
> This fixes in passing a Coverity-spotted issue (CID 1350038) where
> we weren't checking the return value from sscanf().
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Fam, this is the commit that introduced the qemu-iotests 059 failure for
vmdk. I think what's happening is that we use an image produced by a
fuzzer, and with the additional checks introduced in this patch, we now
fail earlier and don't test the condition any more that we wanted to
test.

So do we need a new version of sample_images/afl9.vmdk.bz2 that has a
valid CID?

Kevin