Re: [Qemu-devel] [PATCH] block/crypto: Simplify block_crypto_co_create_opts_luks to avoid a memory leak

[Philippe Mathieu-Daudé]

On 07/05/2018 07:20 AM, Kevin Wolf wrote:
> Am 04.07.2018 um 17:02 hat Philippe Mathieu-Daudé geschrieben:
>> After 1ec4f4160a1 Coverity reported:
>>
>>   Variable cryptoopts going out of scope leaks the storage it points to.
>>
>> Fixes: Coverity CID 1393782 (Resource leak)
>> Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
> 
> I already sent a much simpler fix:
> [PATCH] block/crypto: Fix memory leak in create error path

Oh OK I searched a bit but missed it.

> The only thing that is needed is replacing the return with a goto.
> Splitting it in three different error paths is unnecessary because the
> cleanup function handle NULL values just fine.

OK, good to know.

>> I think this check is superfluous but I respected the previous code:
>>
>>      ret = block_crypto_co_create_generic(bs, size, create_opts, errp);
>>      if (ret > 0) {
>>          ret = 0;
>>      }
> 
> It is wrong, too. The old code keep the error code, goto fail skipped
> the ret = 0.

So this is not particularly wrong but as superfluous as the current use :)

ret = 0 is only useful if block_crypto_co_create_generic() returned a
value > 0, which seems unlikely.

Regards,

Phil.