CVE-2021-47650: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.3% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: ASoC: soc-compress: prevent the potentially use of null pointer There is one call trace that snd_soc_register_card() ->snd_soc_bind_card()->soc_init_pcm_runtime() ->snd_soc_dai_compress_new()->snd_soc_new_compress(). In the trace the 'codec_dai' transfers from card->dai_link, and we can see from the snd_soc_add_pcm_runtime() in snd_soc_bind_card() that, if value of card->dai_link->num_codecs is 0, then 'codec_dai' could be null pointer caused by index out of bound in 'asoc_rtd_to_codec(rtd, 0)'. And snd_soc_register_card() is called by various platforms. Therefore, it is better to add the check in the case of misusing. And because 'cpu_dai' has already checked in soc_init_pcm_runtime(), there is no need to check again. Adding the check as follow, then if 'codec_dai' is null, snd_soc_new_compress() will not pass through the check 'if (playback + capture != 1)', avoiding the leftover use of 'codec_dai'.

Affected products

• Linux Linux Kernel: from 5.4, before 5.4.189 (fixed in 5.4.189); from 5.5, before 5.10.110 (fixed in 5.10.110); from 5.11, before 5.15.33 (fixed in 5.15.33); from 5.16, before 5.16.19 (fixed in 5.16.19); from 5.17, before 5.17.2 (fixed in 5.17.2)

Published 2025-02-26. Last modified 2026-06-17.