#VU93052 NULL pointer dereference in Linux kernel - CVE-2021-47275

Vulnerability identifier: #VU93052

Vulnerability risk: Low

CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-47275

CWE-ID: CWE-476

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to NULL pointer dereference within the cached_dev_cache_miss() function in drivers/md/bcache/request.c. A local user can perform a denial of service (DoS) attack.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 5.12, 5.12 rc1, 5.12 rc2, 5.12 rc3, 5.12 rc4, 5.12 rc6, 5.12 rc8, 5.12.1, 5.12.2, 5.12.3, 5.12.4, 5.12.5, 5.12.6, 5.12.7, 5.12.8, 5.12.9, 5.12.10, 5.13 rc1, 5.13 rc4, 5.13 rc5

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External links
https://git.kernel.org/stable/c/555002a840ab88468e252b0eedf0b05e2ce7099c
https://git.kernel.org/stable/c/41fe8d088e96472f63164e213de44ec77be69478
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.11
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.13

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.