Subject: Re: [PATCH] ipaddrlabel: Fix descriptor leak in flush_addrlabel()

From: Donald Hunter <[email-masked]>
Date: Thu, 08 Feb 2024 13:32:11 +0000

Maks Mishin <[email-masked]> writes:

> Added closure of descriptor `rth2.fd` created by rtnl_open() when
> returning from function.
>
> Signed-off-by: Maks Mishin <[email-masked]>
> ---
>  ip/ipaddrlabel.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/ip/ipaddrlabel.c b/ip/ipaddrlabel.c
> index b045827a..3857fcf5 100644
> --- a/ip/ipaddrlabel.c
> +++ b/ip/ipaddrlabel.c
> @@ -201,8 +201,10 @@ static int flush_addrlabel(struct nlmsghdr *n, void *arg)
>  		n->nlmsg_type = RTM_DELADDRLABEL;
>  		n->nlmsg_flags = NLM_F_REQUEST;
>  
> -		if (rtnl_open(&rth2, 0) < 0)
> +		if (rtnl_open(&rth2, 0) < 0) {
> +			rtnl_close(&rth2);

This change is unnecessary. You're calling rtnl_close() in the case where
rtnl_open() just failed so there's nothing to close.

>  			return -1;
> +		}
>  
>  		if (rtnl_talk(&rth2, n, NULL) < 0)
>  			return -2;