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From:   Red Hat Product Security <secalert@redhat.com>
Subject: [engineering.redhat.com #494735] Re: [PATCH] nbd_genl_status: null check for nla_nest_start
Reply-To: secalert@redhat.com
In-Reply-To: <20190729164226.22632-1-navid.emamdoost@gmail.com>
References: <RT-Ticket-494735@engineering.redhat.com>
 <20190729130912.7imtg3hfnvb4lt2y@MacBook-Pro-91.local>
 <20190729164226.22632-1-navid.emamdoost@gmail.com>
Message-ID: <rt-4.0.13-5201-1564465920-1304.494735-5-0@engineering.redhat.com>
RT-Ticket: engineering.redhat.com #494735
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RT-Originator: darunesh@redhat.com
To:     navid.emamdoost@gmail.com
CC:     axboe@kernel.dk, emamd001@umn.edu, josef@toxicpanda.com,
        kjlu@umn.edu, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, nbd@other.debian.org,
        smccaman@umn.edu
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Date:   Tue, 30 Jul 2019 01:52:01 -0400
Sender: linux-kernel-owner@vger.kernel.org
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Hi Navid,

Thank you for you report. I have forwarded this to our analysis team. Once I'll
get an update on your reported vulnerability and it's patched I'll let you
know.
Please let me know if you have any questions or concerns.

On Mon Jul 29 12:42:56 2019, navid.emamdoost@gmail.com wrote:
> nla_nest_start may fail and return NULL. The check is inserted, and
> errno is selected based on other call sites within the same source
> code.
> Update: removed extra new line.
>
> Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
> ---
> drivers/block/nbd.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
> index 9bcde2325893..2410812d1e82 100644
> --- a/drivers/block/nbd.c
> +++ b/drivers/block/nbd.c
> @@ -2149,6 +2149,11 @@ static int nbd_genl_status(struct sk_buff *skb,
> struct genl_info *info)
> }
>
> dev_list = nla_nest_start_noflag(reply, NBD_ATTR_DEVICE_LIST);
> + if (!dev_list) {
> + ret = -EMSGSIZE;
> + goto out;
> + }
> +
> if (index == -1) {
> ret = idr_for_each(&nbd_index_idr, &status_cb, reply);
> if (ret) {


--
Best Regards,
Dhananjay Arunesh, Red Hat Product Security
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