#VU90742 Improper locking in Linux kernel - CVE-2021-47421

Vulnerability identifier: #VU90742

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-2021-47421

CWE-ID: CWE-667

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 improper locking within the amdgpu_pci_error_detected() and amdgpu_pci_resume() functions in drivers/gpu/drm/amd/amdgpu/amdgpu_device.c. A local user can perform a denial of service (DoS) attack.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 5.14, 5.14 rc1, 5.14 rc2, 5.14 rc3, 5.14 rc4, 5.14 rc7, 5.14.0-49.el9, 5.14.1, 5.14.2, 5.14.3, 5.14.4, 5.14.5, 5.14.6, 5.14.7, 5.14.8, 5.14.9, 5.14.10, 5.14.11, 5.15 rc1, 5.15 rc2, 5.15 rc3, 5.15 rc4, 5.15 rc5, 5.15 rc6, 5.15 rc7

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External links
https://git.kernel.org/stable/c/72e9a1bf9b722628c28092e0c2cd8717edd201dc
https://git.kernel.org/stable/c/248b061689a40f4fed05252ee2c89f87cf26d7d8
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.14.12
https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.15

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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.