Re: [PATCH] tools/bootconfig: fix resource leak in apply_xbc()

From: Markus Elfring
Date: Thu May 07 2020 - 16:30:54 EST


> The @data and @fd is leak in the error path of apply_xbc(), so this
> patch fix it.

I suggest to improve this change description.

* Please use an imperative wording.

* Would you like to add the tag âFixesâ?


> +++ b/tools/bootconfig/main.c
> @@ -314,6 +314,7 @@ int apply_xbc(const char *path, const char *xbc_path)
> ret = delete_xbc(path);
> if (ret < 0) {
> pr_err("Failed to delete previous boot config: %d\n", ret);
> + free(data);
> return ret;
> }

I propose to adjust the exception handling.
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/coding-style.rst?id=6e7f2eacf09811d092c1b41263108ac7fe0d089d#n450

- return ret;
+ goto free_data;


> @@ -321,24 +322,26 @@ int apply_xbc(const char *path, const char *xbc_path)
> fd = open(path, O_RDWR | O_APPEND);
> if (fd < 0) {
> pr_err("Failed to open %s: %d\n", path, fd);
> + free(data);
> return fd;

- return fd;
+ ret = fd;
+ goto free_data;


> }
> /* TODO: Ensure the @path is initramfs/initrd image */
> ret = write(fd, data, size + 8);
> if (ret < 0) {
> pr_err("Failed to apply a boot config: %d\n", ret);
> - return ret;
> + goto out;

+ goto free_data;


> }
> /* Write a magic word of the bootconfig */
> ret = write(fd, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN);
> if (ret < 0) {

- if (ret < 0) {
+ if (ret < 0)


> pr_err("Failed to apply a boot config magic: %d\n", ret);
> - return ret;
> + goto out;

I suggest to avoid an extra jump at such a place.


> }

- }
+


> +out:

+close_fd:
> close(fd);

+free_data:
> free(data);


How do you think about to complete the error handling also at other
source code places?

Regards,
Markus