Re: [PATCH 5/6] bundle: don't leak an fd in case of early return

From: Jeff King <peff@peff.net>
Date: Mar 30, 2016, 01:17 UTC
Message-ID: <20160330011743.GD2237@sigill.intra.peff.net>
In-Reply-To: <1459298333-21899-6-git-send-email-sbeller@google.com>

On Tue, Mar 29, 2016 at 05:38:52PM -0700, Stefan Beller wrote:

Show 23 quoted lines

> In successful operation `write_pack_data` will close the `bundle_fd`,
> but when we exit early, we need to take care of the file descriptor
> ourselves.
> 
> Signed-off-by: Stefan Beller <sbeller@google.com>
> ---
>  bundle.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/bundle.c b/bundle.c
> index 506ac49..04d62af 100644
> --- a/bundle.c
> +++ b/bundle.c
> @@ -434,8 +434,11 @@ int create_bundle(struct bundle_header *header, const char *path,
>  	init_revisions(&revs, NULL);
>  
>  	/* write prerequisites */
> -	if (compute_and_write_prerequisites(bundle_fd, &revs, argc, argv))
> +	if (compute_and_write_prerequisites(bundle_fd, &revs, argc, argv)) {
> +		if (!bundle_to_stdout)
> +			close(bundle_fd);
>  		return -1;
> +	}

Makes sense. Should we also be rolling back the lock file? It happens automatically at program exit, of course, but we are in library code here that should not rely on that.

Show 10 quoted lines

> @@ -447,8 +450,11 @@ int create_bundle(struct bundle_header *header, const char *path,
>  	ref_count = write_bundle_refs(bundle_fd, &revs);
>  	if (!ref_count)
>  		die(_("Refusing to create empty bundle."));
> -	else if (ref_count < 0)
> +	else if (ref_count < 0) {
> +		if (!bundle_to_stdout)
> +			close(bundle_fd);
>  		return -1;
> +	}

Ditto here, and in the error return from write_pack_data(). There are enough spots that it may be worth setting up a "goto err" path.

-Peff