Re: [PATCH] clk: imx: clk-imx8mm: fix memory leak issue in 'imx8mm_clocks_probe'

From: Dongliang Mu
Date: Fri Apr 14 2023 - 21:57:23 EST



On 2023/4/15 00:38, Dan Carpenter wrote:
On Thu, Apr 13, 2023 at 12:06:59PM -0700, Stephen Boyd wrote:
Quoting Zhou Shide (2023-04-12 20:24:39)
The function imx8mm_clocks_probe() has two main issues:
- The of_iomap() function may cause a memory leak.
- Memory allocated for 'clk_hw_data' may not be freed properly
in some paths.

To fix these issues, this commit replaces the use of of_iomap()
with devm_of_iomap() and replaces kzalloc() with devm_kzalloc().
This ensures that all memory is properly managed and automatically
freed when the device is removed.

In addition, when devm_of_iomap() allocates memory with an error,
it will first jump to label "unregister_hws" and
then return PTR_ ERR(base).

Fixes: 9c71f9ea35d7 ("clk: imx: imx8mm: Switch to clk_hw based API")
Fixes: ba5625c3e272 ("clk: imx: Add clock driver support for imx8mm")
Signed-off-by: Zhou Shide <u201911681@xxxxxxxxxxx>
---
The issue is discovered by static analysis, and the patch is not tested yet.
And you're not coordinating with each other?

This is a university program. The patches are reviewed by his professor
and teaching assistants etc. I've been reviewing some of these patches
as well because of they're using Smatch.

Thanks for your explanation, Dan. We are from Huazhong University of Science and Technology.

Some undergraduate and graduatestudents who are interested in Linux Kernel are guided by me [1] and Dan to contribute into our kernel community.

We found Smatch is really great in finding kernel issues and these issues are suitable for undergraduate students. Therefore, I contacted Dan to do a favor for patch interview. And our internal review are publicly hosted in a google group [2].

Please let me know if you have any questions.

[1] https://mudongliang.github.io/about/

[2] https://groups.google.com/g/hust-os-kernel-patches


regards,
dan carpenter