---
id: CVE-2021-47650
title: 'ASoC: soc-compress: prevent the potentially use of null pointer'
summary: |-
  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()
  ->sn…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 467fece8fbc6774a3a3bd0981e1a342fb5022706 <
    68a69ad8df959e5211ed4a8e120783b2d352ea74
  - >-
    Linux >= 467fece8fbc6774a3a3bd0981e1a342fb5022706 <
    4639c1d97f385f4784f44d66a3da0672f4951ada
  - >-
    Linux >= 467fece8fbc6774a3a3bd0981e1a342fb5022706 <
    fc237b8d624f4bcb0f21a532627ce4e3b3a85569
  - >-
    Linux >= 467fece8fbc6774a3a3bd0981e1a342fb5022706 <
    08af6da684b44097ea09f1d74d5858b837ed203b
  - >-
    Linux >= 467fece8fbc6774a3a3bd0981e1a342fb5022706 <
    f69a75cb8a98c6c487d620442c68595726a69f60
  - >-
    Linux >= 467fece8fbc6774a3a3bd0981e1a342fb5022706 <
    de2c6f98817fa5decb9b7d3b3a8a3ab864c10588
  - Linux 5.4
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-05T19:42:28.630527Z'
published: '2025-02-26'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T19:49:35.327Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2021-47650'
references:
  - url: 'https://git.kernel.org/stable/c/68a69ad8df959e5211ed4a8e120783b2d352ea74'
  - url: 'https://git.kernel.org/stable/c/4639c1d97f385f4784f44d66a3da0672f4951ada'
  - url: 'https://git.kernel.org/stable/c/fc237b8d624f4bcb0f21a532627ce4e3b3a85569'
  - url: 'https://git.kernel.org/stable/c/08af6da684b44097ea09f1d74d5858b837ed203b'
  - url: 'https://git.kernel.org/stable/c/f69a75cb8a98c6c487d620442c68595726a69f60'
  - url: 'https://git.kernel.org/stable/c/de2c6f98817fa5decb9b7d3b3a8a3ab864c10588'
tags:
  - cve.org
epss: 0.00256
epssPercentile: 0.17296
ingestedAt: '2026-11-05T22:38:31.559Z'
---

## Overview

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

- `Linux >= 467fece8fbc6774a3a3bd0981e1a342fb5022706 < 68a69ad8df959e5211ed4a8e120783b2d352ea74`
- `Linux >= 467fece8fbc6774a3a3bd0981e1a342fb5022706 < 4639c1d97f385f4784f44d66a3da0672f4951ada`
- `Linux >= 467fece8fbc6774a3a3bd0981e1a342fb5022706 < fc237b8d624f4bcb0f21a532627ce4e3b3a85569`
- `Linux >= 467fece8fbc6774a3a3bd0981e1a342fb5022706 < 08af6da684b44097ea09f1d74d5858b837ed203b`
- `Linux >= 467fece8fbc6774a3a3bd0981e1a342fb5022706 < f69a75cb8a98c6c487d620442c68595726a69f60`
- `Linux >= 467fece8fbc6774a3a3bd0981e1a342fb5022706 < de2c6f98817fa5decb9b7d3b3a8a3ab864c10588`
- `Linux 5.4`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.