Re: [PATCH] linux-user: Return EINVAL for getgroups() with negative gidsetsize

[Michael Tokarev]

02.06.2023 20:48, Peter Maydell wrote:
> Coverity doesn't like the way we might end up calling getgroups()
> with a NULL grouplist pointer. This is fine for the special case
> of gidsetsize == 0, but we will also do it if the guest passes
> us a negative gidsetsize. (CID 1512465)
>
> Explicitly fail the negative gidsetsize with EINVAL, as the kernel
> does. This means we definitely only call the libc getgroups()
> with valid parameters.
>
> Possibly Coverity may still complain about getgroups(0, NULL), but
> that would be a false positive.
>
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

I especially kept the negative case like this when initially writing
this code, thinking to return whatever error the kernel will return.
But I guess it doesn't really matter here, and the less fragile corner
cases, the better.

Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>

Thanks,

/mjt