[PATCH v4] tools/bootconfig: fix resource leak in apply_xbc()

[PATCH v4] tools/bootconfig: fix resource leak in apply_xbc()

[Yunfeng Ye]

An error is found by a internel analysis tool:
  "Memory leak: data" and "Resource leak: fd" in tools/bootconfig/main.c

Fix the @data and @fd allocations that are leaked in the error path of
apply_xbc().

Fixes: 85c46b78da58 ("bootconfig: Add bootconfig magic word for indicating bootconfig explicitly")
Fixes: 950313ebf79c ("tools: bootconfig: Add bootconfig command")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
v3 -> v4:
 - update the commit message

v2 -> v3:
 - set 'ret' to 0 before returning on success

v1 -> v2:
 - complete the error handling at other error path
 - add "Fixes" tag

 tools/bootconfig/main.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/tools/bootconfig/main.c b/tools/bootconfig/main.c
index 16b9a420e6fd..17a9837dcfaa 100644
--- a/tools/bootconfig/main.c
+++ b/tools/bootconfig/main.c
@@ -314,31 +314,35 @@ 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);
-		return ret;
+		goto free_data;
 	}

 	/* Apply new one */
 	fd = open(path, O_RDWR | O_APPEND);
 	if (fd < 0) {
 		pr_err("Failed to open %s: %d\n", path, 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 close_fd;
 	}
 	/* Write a magic word of the bootconfig */
 	ret = write(fd, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN);
-	if (ret < 0) {
+	if (ret < 0)
 		pr_err("Failed to apply a boot config magic: %d\n", ret);
-		return ret;
-	}
+
+	ret = 0;
+
+close_fd:
 	close(fd);
+free_data:
 	free(data);

-	return 0;
+	return ret;
 }

 int usage(void)
-- 
1.8.3.1

Re: [PATCH v4] tools/bootconfig: fix resource leak in apply_xbc()

[Markus Elfring]

> An error is found by a internel analysis tool:
>   "Memory leak: data" and "Resource leak: fd" in tools/bootconfig/main.c

If such an information will ever be integrated into a final commit message,
I would prefer a wording variant like the following.

   Two issues were pointed out by an internal source code analysis tool:
   * Line …:
     Memory leak: data

   * Line …:
     Resource leak: fd


Each of these issues has got a different importance for this function implementation.


> Fix the @data and @fd allocations that are leaked in the error path of
> apply_xbc().

How do you think about to replace the @ characters by other delimiters
for the relevant identifiers?

Regards,
Markus

Re: [PATCH v4] tools/bootconfig: fix resource leak in apply_xbc()

[Dan Carpenter]

Looks good thanks!

Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>

regards,
dan carpenter

Re: [PATCH v4] tools/bootconfig: fix resource leak in apply_xbc()

[Dan Carpenter]

On Fri, May 08, 2020 at 05:40:09PM +0300, Dan Carpenter wrote:
> Looks good thanks!
> 
> Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>

I was also absolutely fine with the v3 patch as well.

regards,
dan carpenter

Re: [PATCH v4] tools/bootconfig: Completion of error handling

[Markus Elfring]

…
> +++ b/tools/bootconfig/main.c
> @@ -314,31 +314,35 @@ int apply_xbc(const char *path, const char *xbc_path)
…
> +close_fd:
>  	close(fd);

Do analysis tools point any software development concerns out
at this source code place?
https://wiki.sei.cmu.edu/confluence/display/c/ERR33-C.+Detect+and+handle+standard+library+errors#ERR33-C.Detectandhandlestandardlibraryerrors-AutomatedDetection

Regards,
Markus