CVE-2025-38522
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-08-16

Last updated on: 2025-11-18

Assigner: kernel.org

Description
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.
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Meta Information
Published
2025-08-16
Last Modified
2025-11-18
Generated
2026-05-07
AI Q&A
2025-08-16
EPSS Evaluated
2026-05-05
NVD
CVE-2025-38522
Affected Vendors & Products
Showing 9 associated CPEs
Vendor Product Version / Range
linux linux_kernel 6.15
linux linux_kernel 6.15
linux linux_kernel 6.16
linux linux_kernel 6.16
linux linux_kernel 6.16
linux linux_kernel 6.16
linux linux_kernel 6.16
linux linux_kernel 6.16
linux linux_kernel From 5.15.160 (inc) to 5.16 (inc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-476 The product dereferences a pointer that it expects to be valid but is NULL.
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability in the Linux kernel involves the function update_locked_rq() being called with a NULL runqueue (rq) pointer. When this happens with preemption enabled, it triggers a warning because __this_cpu_write(), used inside update_locked_rq(), is unsafe in preemptible contexts. The issue arises when operations are invoked from an unlocked context where rq is NULL, but update_locked_rq() is still called. The fix prevents calling update_locked_rq() when rq is NULL, avoiding unsafe operations in preemptible contexts.


How can this vulnerability impact me? :

This vulnerability can cause kernel warnings or potential instability due to unsafe calls in preemptible contexts, which might lead to system crashes or unpredictable behavior in the Linux kernel. It affects the kernel's scheduling operations and could impact system reliability.


What immediate steps should I take to mitigate this vulnerability?

The vulnerability is resolved by preventing calls to update_locked_rq() with a NULL runqueue pointer in the Linux kernel. Immediate mitigation involves updating your Linux kernel to a version that includes this fix, ensuring that update_locked_rq() is only called when the runqueue pointer is non-NULL.


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