linux-kernel - Re: [PATCH] xen/privcmd: allow fetching resource sizes

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <555ba53c-1b6b-6cf7-9887-52d4179f7456@oracle.com>
Date:   Mon, 11 Jan 2021 17:09:54 -0500
From:   boris.ostrovsky@...cle.com
To:     Roger Pau Monne <roger.pau@...rix.com>,
        linux-kernel@...r.kernel.org
Cc:     Juergen Gross <jgross@...e.com>,
        Stefano Stabellini <sstabellini@...nel.org>,
        Paul Durrant <paul.durrant@...rix.com>,
        xen-devel@...ts.xenproject.org
Subject: Re: [PATCH] xen/privcmd: allow fetching resource sizes


On 1/11/21 10:29 AM, Roger Pau Monne wrote:
>  
> +	xdata.domid = kdata.dom;
> +	xdata.type = kdata.type;
> +	xdata.id = kdata.id;
> +
> +	if (!kdata.addr && !kdata.num) {


I think we should not allow only one of them to be zero. If it's only kdata.num then we will end up with pfns array set to ZERO_SIZE_PTR (which is 0x10). We seem to be OK in that we are not derefencing pfns (either in kernel or in hypervisor) if number of frames is zero but IMO we shouldn't be tempting the fate.


(And if it's only kdata.addr then we will get a vma but I am not sure it will do what we want.)


-boris