public inbox for netdev@vger.kernel.org 
 help / color / mirror / Atom feed
From: Petr Machata <petrm@nvidia•com>
To: heminhong <heminhong@kylinos•cn>
Cc: <stephen@networkplumber•org>, <netdev@vger•kernel.org>
Subject: Re: [PATCH v3] iproute2: prevent memory leak
Date: Wed, 15 Nov 2023 11:23:28 +0100	[thread overview]
Message-ID: <87y1ezwbk8.fsf@nvidia.com> (raw)
In-Reply-To: <20231115075650.33219-1-heminhong@kylinos.cn>


heminhong <heminhong@kylinos•cn> writes:

> When the return value of rtnl_talk() is greater than
> or equal to 0, 'answer' will be allocated.
> The 'answer' should be free after using,
> otherwise it will cause memory leak.

The patch also frees the memory when rtnl_talk() returns < 0. In that
case the answer has not been initialized. You should probably initialize
the answer to NULL.

> Signed-off-by: heminhong <heminhong@kylinos•cn>
> ---
>  ip/link_gre.c    | 1 +
>  ip/link_gre6.c   | 1 +
>  ip/link_ip6tnl.c | 1 +
>  ip/link_iptnl.c  | 1 +
>  ip/link_vti.c    | 1 +
>  ip/link_vti6.c   | 1 +
>  6 files changed, 6 insertions(+)
>
> diff --git a/ip/link_gre.c b/ip/link_gre.c
> index 74a5b5e9..3d3fcbae 100644
> --- a/ip/link_gre.c
> +++ b/ip/link_gre.c
> @@ -113,6 +113,7 @@ static int gre_parse_opt(struct link_util *lu, int argc, char **argv,
>  get_failed:
>  			fprintf(stderr,
>  				"Failed to get existing tunnel info.\n");
> +			free(answer);
>  			return -1;
>  		}
>  

The context of this hunk is:

 	struct nlmsghdr *answer;
 
 	... answer untouched here ...
 
 		if (rtnl_talk(&rth, &req.n, &answer) < 0) {
 get_failed:
+			free(answer);
 			fprintf(stderr,
 				"Failed to get existing tunnel info.\n");
 			return -1;
 		}

If rtnl_talk() fails, answer is never initialized, so passing it to free
is invalid.

  reply	other threads:[~2023-11-15 10:33 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-14  9:24 [PATCH] iproute2: prevent memory leak heminhong
2023-11-15  0:36 ` Stephen Hemminger
2023-11-15  2:37   ` [PATCH v2] " heminhong
2023-11-15  3:32     ` Florian Westphal
2023-11-15  3:33     ` Stephen Hemminger
2023-11-15  7:56       ` [PATCH v3] " heminhong
2023-11-15 10:23         ` Petr Machata [this message]
2023-11-16  3:13           ` [PATCH v4] " heminhong
2023-11-16 12:04             ` Andrea Claudi
2023-11-16 23:05             ` Stephen Hemminger
2023-11-17  0:45               ` Andrea Claudi
2023-11-17  3:31                 ` Stephen Hemminger
2023-11-17 17:20             ` patchwork-bot+netdevbpf

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87y1ezwbk8.fsf@nvidia.com \
    --to=petrm@nvidia$(echo .)com \
    --cc=heminhong@kylinos$(echo .)cn \
    --cc=netdev@vger$(echo .)kernel.org \
    --cc=stephen@networkplumber$(echo .)org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox