Message-ID: <782a6f2d-84ae-3530-7e3c-07f31a4f303b@suse.de>
Date:   Tue, 7 Mar 2023 11:43:46 +0300
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Subject: Re: [PATCH] net: ieee802154: fix a null pointer in
 nl802154_trigger_scan
To:     Dongliang Mu <dzm91@hust.edu.cn>,
        Alexander Aring <alex.aring@gmail.com>,
        Stefan Schmidt <stefan@datenfreihafen.org>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>
Cc:     syzbot+bd85b31816913a32e473@syzkaller.appspotmail.com,
        linux-wpan@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20230307073004.74224-1-dzm91@hust.edu.cn>
Content-Language: en-US
From:   Denis Kirjanov <dkirjanov@suse.de>
In-Reply-To: <20230307073004.74224-1-dzm91@hust.edu.cn>
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On 3/7/23 10:30, Dongliang Mu wrote:
> There is a null pointer dereference if NL802154_ATTR_SCAN_TYPE is
> not set by the user.
> 
> Fix this by adding a null pointer check.
> 
> Reported-and-tested-by: syzbot+bd85b31816913a32e473@syzkaller.appspotmail.com
> Signed-off-by: Dongliang Mu <dzm91@hust.edu.cn>

Please add a Fixes: tag 

> ---
>  net/ieee802154/nl802154.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/net/ieee802154/nl802154.c b/net/ieee802154/nl802154.c
> index 2215f576ee37..1cf00cffd63f 100644
> --- a/net/ieee802154/nl802154.c
> +++ b/net/ieee802154/nl802154.c
> @@ -1412,7 +1412,8 @@ static int nl802154_trigger_scan(struct sk_buff *skb, struct genl_info *info)
>  		return -EOPNOTSUPP;
>  	}
>  
> -	if (!nla_get_u8(info->attrs[NL802154_ATTR_SCAN_TYPE])) {
> +	if (!info->attrs[NL802154_ATTR_SCAN_TYPE] ||
> +	    !nla_get_u8(info->attrs[NL802154_ATTR_SCAN_TYPE])) {
>  		NL_SET_ERR_MSG(info->extack, "Malformed request, missing scan type");
>  		return -EINVAL;
>  	}