[PATCH bpf-next v2] selftests/bpf:fix a resource leak

[PATCH bpf-next v2] selftests/bpf:fix a resource leak

[Zhu Jun]

The requested resources should be closed before return
in main(), otherwise resource leak will occur

Signed-off-by: Zhu Jun <zhujun2@cmss.chinamobile.com>
---
Changes in v2:
 - check for cg_fd >= 0 and have just one out label

 tools/testing/selftests/bpf/test_sockmap.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/bpf/test_sockmap.c b/tools/testing/selftests/bpf/test_sockmap.c
index a34e95040994..285a9a714666 100644
--- a/tools/testing/selftests/bpf/test_sockmap.c
+++ b/tools/testing/selftests/bpf/test_sockmap.c
@@ -2075,8 +2075,10 @@ int main(int argc, char **argv)
 
 	if (!cg_fd) {
 		cg_fd = cgroup_setup_and_join(CG_PATH);
-		if (cg_fd < 0)
-			return cg_fd;
+		if (cg_fd < 0) {
+			err = cg_fd;
+			goto out;
+		}
 		cg_created = 1;
 	}
 
@@ -2092,7 +2094,7 @@ int main(int argc, char **argv)
 	if (err) {
 		fprintf(stderr, "populate program: (%s) %s\n",
 			bpf_file, strerror(errno));
-		return 1;
+		goto out;
 	}
 	running = 1;
 
@@ -2109,7 +2111,8 @@ int main(int argc, char **argv)
 		free(options.whitelist);
 	if (options.blacklist)
 		free(options.blacklist);
-	close(cg_fd);
+	if (cg_fd >= 0)
+		close(cg_fd);
 	if (cg_created)
 		cleanup_cgroup_environment();
 	return err;
-- 
2.17.1

Re: [PATCH bpf-next v2] selftests/bpf:fix a resource leak

[Shuah Khan]

On 7/9/24 19:59, Zhu Jun wrote:
> The requested resources should be closed before return
> in main(), otherwise resource leak will occur
> 
> Signed-off-by: Zhu Jun <zhujun2@cmss.chinamobile.com>

How did you find this problem? Please give more details
on the tool used including the output from the tool.
> ---
> Changes in v2:
>   - check for cg_fd >= 0 and have just one out label
> 
>   tools/testing/selftests/bpf/test_sockmap.c | 11 +++++++----
>   1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/testing/selftests/bpf/test_sockmap.c b/tools/testing/selftests/bpf/test_sockmap.c
> index a34e95040994..285a9a714666 100644
> --- a/tools/testing/selftests/bpf/test_sockmap.c
> +++ b/tools/testing/selftests/bpf/test_sockmap.c
> @@ -2075,8 +2075,10 @@ int main(int argc, char **argv)
>   
>   	if (!cg_fd) {
>   		cg_fd = cgroup_setup_and_join(CG_PATH);
> -		if (cg_fd < 0)
> -			return cg_fd;
> +		if (cg_fd < 0) {
> +			err = cg_fd;
> +			goto out;
> +		}

I don't this this improves the code - it makes it more complex.
If you want to improve this - add the same error message that
gets printed out for

case 'c':

in argument parsing.

fprintf(stderr, "ERROR: (%i) open cg path failed: %s\n",
                  cg_fd, optarg);
>   		cg_created = 1;
>   	}
>   
> @@ -2092,7 +2094,7 @@ int main(int argc, char **argv)
>   	if (err) {
>   		fprintf(stderr, "populate program: (%s) %s\n",
>   			bpf_file, strerror(errno));
> -		return 1;
> +		goto out;

This looks good to me.

>   	}
>   	running = 1;
>   
> @@ -2109,7 +2111,8 @@ int main(int argc, char **argv)
>   		free(options.whitelist);
>   	if (options.blacklist)
>   		free(options.blacklist);
> -	close(cg_fd);
> +	if (cg_fd >= 0)

Why is this check necessary?
> +		close(cg_fd);


>   	if (cg_created)
>   		cleanup_cgroup_environment();
>   	return err;

thanks,
-- Shuah