[Libguestfs] [libnbd PATCH 3/3] api: Add new API nbd_set_pread_initialize()

[Richard W.M. Jones]

On Wed, Feb 09, 2022 at 04:07:26PM -0600, Eric Blake wrote:
> +  "set_pread_initialize", {
> +    default_call with
> +    args = [Bool "request"]; ret = RErr;
> +    shortdesc = "control whether libnbd pre-initializes read buffers";
> +    longdesc = "\
> +By default, libnbd will pre-initialize the contents of a buffer
> +passed to calls such as L<nbd_pread(3)> to all zeroes prior to checking
> +for any other errors, so that even if a client application passed in an
> +uninitialized buffer but fails to check for errors, it will not result
> +in a potential security risk caused by an accidental leak of prior heap
> +contents.  However, for a client application that has audited that an
> +uninitialized buffer is never dereferenced, or which performs its own
> +pre-initialization, libnbd's sanitization efforts merely pessimize
> +performance.
> +
> +Calling this function with C<request> set to false tells libnbd to
> +skip the buffer initialization step in read commands.";
> +    see_also = [Link "get_pread_initialize";
> +                Link "set_strict_mode";
> +                Link "pread"; Link "pread_structured"; Link "aio_pread";
> +                Link "aio_pread_structured"];
> +  };

Could it be worth mentioning CVE-2022-0485 by name in the text here?
And/or linking to:
https://listman.redhat.com/archives/libguestfs/2022-February/msg00104.html

Anyway the whole patch series looks good, so:

Reviewed-by: Richard W.M. Jones <rjones at redhat.com>

Rich.

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