What’s Vulnerable › Vulnerabilities

CVE-2021-47289: ACPI: fix NULL pointer dereference

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2024-05-21 · updated 2026-06-17
• Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: ACPI: fix NULL pointer dereference Commit 71f642833284 ("ACPI: utils: Fix reference counting in for_each_acpi_dev_match()") started doing "acpi_dev_put()" on a pointer that was possibly NULL. That fails miserably, because that helper inline function is not set up to handle that case. Just make acpi_dev_put() silently accept a NULL pointer, rather than calling down to put_device() with an invalid offset off that NULL pointer.

Affected products

• Linux kernel: before 5.4.139; from 5.5 before 5.10.57; from 5.11 before 5.13.6; 5.14-rc1, 5.14-rc2 — fixed in 5.10.57, 5.13.6, 5.4.139

How to fix

Upgrade to a fixed version: Linux kernel 5.10.57, 5.13.6, 5.4.139. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/38f54217b423c0101d03a00feec6fb8ec608b12e
• https://git.kernel.org/stable/c/cae3fa3d8165761f3000f523b11cfa1cd35206bc
• https://git.kernel.org/stable/c/ccf23a0888077a25a0793a746c3941db2a7562e4
• https://git.kernel.org/stable/c/fc68f42aa737dc15e7665a4101d4168aadb8e4c4
• https://git.kernel.org/stable/c/38f54217b423c0101d03a00feec6fb8ec608b12e
• https://git.kernel.org/stable/c/cae3fa3d8165761f3000f523b11cfa1cd35206bc
• https://git.kernel.org/stable/c/ccf23a0888077a25a0793a746c3941db2a7562e4
• https://git.kernel.org/stable/c/fc68f42aa737dc15e7665a4101d4168aadb8e4c4

Get alerted when CVE-2021-47289 or the next vulnerability affects your stack