CVE-2021-47650
MediumIn 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'.
CVSS 3.1 score
5.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness type
CWE-476CVE-2021-47650 is a NULL Pointer Dereference vulnerability
What is NULL Pointer Dereference?
The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. Learn more on MITRE CWE
Affected versions
Linux kernel versions
5.4
and later are affected. Fixed in
5.4.189,
5.10.110,
5.15.33,
5.16.19,
5.17.2,
5.18
and their respective stable series.
References
The following references provide additional information about CVE-2021-47650 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/08af6da684b44097ea09f1d74d5858b837ed203b
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PatchKernel patch commithttps://git.kernel.org/stable/c/4639c1d97f385f4784f44d66a3da0672f4951ada
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PatchKernel patch commithttps://git.kernel.org/stable/c/68a69ad8df959e5211ed4a8e120783b2d352ea74
Frequently asked questions
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What is CVE-2021-47650?
CVE-2021-47650 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 , classified as a NULL Pointer Dereference flaw (CWE-476) . It affects Linux kernel versions from 5.4 onward and has been patched in 5.4.189, 5.10.110, 5.15.33 and others. CVE-2021-47650 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2021-47650?
CVE-2021-47650 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2021-47650?
Yes — CVE-2021-47650 has been patched. Fixed versions include 5.4.189, 5.10.110, 5.15.33 and others. If you are running Linux kernel 5.4 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2021-47650 actively exploited?
No — CVE-2021-47650 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is NULL Pointer Dereference (CWE-476)?
The product dereferences a pointer that it expects to be valid but is NULL, typically causing a crash. View CWE-476 on MITRE CWE →