Subject: Re: [PATCH v5 2/2] KEYS: Avoid false positive ENOMEM error on key read

From: Jarkko Sakkinen <[email-masked]>
Date: Thu, 19 Mar 2020 21:46:50 +0200

On Wed, Mar 18, 2020 at 06:14:57PM -0400, Waiman Long wrote:
> +			 * It is possible, though unlikely, that the key
> +			 * changes in between the up_read->down_read period.
> +			 * If the key becomes longer, we will have to
> +			 * allocate a larger buffer and redo the key read
> +			 * again.
> +			 */
> +			if (!tmpbuf || unlikely(ret > tmpbuflen)) {

Shouldn't you check that tmpbuflen stays below buflen (why else
you had made copy of buflen otherwise)?

/Jarkko