Re: [2/2] ASoC: samsung: odroid: fix a double-free issue for cpu_dai

Re: [2/2] ASoC: samsung: odroid: fix a double-free issue for cpu_dai

[Markus Elfring]

> These two updates fix two different bugs.

I can follow this view to some degree.


> and the other is the double-free issue

This programming error affects also the use of data structures which became invalid.
https://cwe.mitre.org/data/definitions/415.html#oc_415_Notes


> So we sent two patches to fix them separately.

You would like to fix something according to two variables (of the data type “device_node *”)
in the same function implementation.
Please combine these corrections in an update step under a topic like
“ASoC: samsung: odroid: Fix handling of device node references in odroid_audio_probe()”.
(The previous update step would contain still a known programming mistake otherwise,
wouldn't it?)

Regards,
Markus

Re: [2/2] ASoC: samsung: odroid: fix a double-free issue for cpu_dai

[Markus Elfring]

> The cpu_dai variable is still being used after the of_node_put() call,

Such an implementation detail is questionable.
https://wiki.sei.cmu.edu/confluence/display/c/MEM30-C.+Do+not+access+freed+memory


> which may result in double-free:

This consequence is also undesirable.
https://cwe.mitre.org/data/definitions/415.html


Now I wonder if two update steps are really appropriate as a fix
instead of using a single update step for the desired correction
in this software module.
Should a commit (including previous ones) usually be correct by itself?

Regards,
Markus