Received-SPF: pass (google.com: domain of linux-nfs-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <5819a1ec-e65f-7c10-00a6-fafae7b12c0f@redhat.com>
Date:   Mon, 28 Feb 2022 15:26:59 -0500
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.5.0
Subject: Re: [PATCH] mountd: Fix potential data corrupter
Content-Language: en-US
From:   Steve Dickson <steved@redhat.com>
To:     Linux NFS Mailing list <linux-nfs@vger.kernel.org>
References: <20220224190604.291491-1-steved@redhat.com>
In-Reply-To: <20220224190604.291491-1-steved@redhat.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 2/24/22 2:06 PM, Steve Dickson wrote:
> Commit 9c99b463 typecast an uint into a int
> to fix a Coverity warning. Potentially this
> could cause a very large rogue value to be
> negative allow the rouge value to index into
> a table causing corruption.
> 
> A check has been added to detect this type
> of situation.
> 
> Signed-off-by: Steve Dickson <steved@redhat.com>
Committed... (tag: nfs-utils-2-6-2-rc3)
With the addition of
   Reported-by: Richard Weinberger <richard@nod.at>

steved.
> ---
>   support/nfs/rpcdispatch.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/support/nfs/rpcdispatch.c b/support/nfs/rpcdispatch.c
> index f7c27c98..7329f419 100644
> --- a/support/nfs/rpcdispatch.c
> +++ b/support/nfs/rpcdispatch.c
> @@ -26,12 +26,13 @@ rpc_dispatch(struct svc_req *rqstp, SVCXPRT *transp,
>   			void *argp, void *resp)
>   {
>   	struct rpc_dentry	*dent;
> +	int rq_vers = (int)rqstp->rq_vers;
>   
> -	if (((int)rqstp->rq_vers) > nvers) {
> +	if (rq_vers < 1 || rq_vers > nvers) {
>   		svcerr_progvers(transp, 1, nvers);
>   		return;
>   	}
> -	dtable += (rqstp->rq_vers - 1);
> +	dtable += (rq_vers - 1);
>   	if (rqstp->rq_proc > dtable->nproc) {
>   		svcerr_noproc(transp);
>   		return;