ASoC: core: Check for rtd == NULL in snd_soc_remove_pcm_runtime()

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: ASoC: core: Check for rtd == NULL in snd_soc_remove_pcm_runtime() snd_soc_remove_pcm_runtime() might be called with rtd == NULL which will leads to null pointer dereference. This was reproduced with topology loading and marking a link as ignore due to missing hardware component on the system. On module removal the soc_tplg_remove_link() would call snd_soc_remove_pcm_runtime() with rtd == NULL since the link was ignored, no runtime was created.

References

• https://git.kernel.org/stable/c/8b465bedc2b417fd27c1d1ab7122882b4b60b1a0
• https://git.kernel.org/stable/c/82ba7b8cf9f6e3bf392a9f08ba3d1c0b200ccb94
• https://git.kernel.org/stable/c/7f8fc03712194fd4e2df28af7f7f7a38205934ef
• https://git.kernel.org/stable/c/41f53afe53a57a7c50323f99424b598190acf192
• https://git.kernel.org/stable/c/2fce20decc6a83f16dd73744150c4e7ea6c97c21
• https://git.kernel.org/stable/c/cecc65827ef3df9754e097582d89569139e6cd1e
• https://git.kernel.org/stable/c/7ce0a7255ce97ed7c54afae83fdbce712a1f0c9e
• https://git.kernel.org/stable/c/2d91cb261cac6d885954b8f5da28b5c176c18131