Linux Kernel up to 6.15.7 update_locked_rq null pointer dereference

Summaryinfo

A vulnerability labeled as critical has been found in Linux Kernel up to 6.15.7. Affected by this vulnerability is the function update_locked_rq. Executing a manipulation can lead to null pointer dereference. This vulnerability is handled as CVE-2025-38522. There is not any exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.15.7 and classified as critical. This vulnerability affects the function update_locked_rq. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. As an impact it is known to affect availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: sched/ext: Prevent update_locked_rq() calls with NULL rq Avoid invoking update_locked_rq() when the runqueue (rq) pointer is NULL in the SCX_CALL_OP and SCX_CALL_OP_RET macros. Previously, calling update_locked_rq(NULL) with preemption enabled could trigger the following warning: BUG: using __this_cpu_write() in preemptible [00000000] This happens because __this_cpu_write() is unsafe to use in preemptible context. rq is NULL when an ops invoked from an unlocked context. In such cases, we don't need to store any rq, since the value should already be NULL (unlocked). Ensure that update_locked_rq() is only called when rq is non-NULL, preventing calling __this_cpu_write() on preemptible context.

The advisory is available at git.kernel.org. This vulnerability was named CVE-2025-38522 since 04/16/2025. Technical details are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 260060 (Linux Distros Unpatched Vulnerability : CVE-2025-38522), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.15.8 eliminates this vulnerability. Applying the patch 237c43037b336e36a49eb9f2daac1c7719ec7f8b/e14fd98c6d66cb76694b12c05768e4f9e8c95664 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (260060), EUVD (EUVD-2025-27881) and CERT Bund (WID-SEC-2025-1858). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• RESF Rocky Linux
• Dell Avamar
• Open Source Linux Kernel
• Dell NetWorker
• Dell Secure Connect Gateway
• IBM QRadar SIEM
• IBM Security Verify Access

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.15.0
• 6.15.1
• 6.15.2
• 6.15.3
• 6.15.4
• 6.15.5
• 6.15.6
• 6.15.7

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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