Kernel warning via NULL runqueue update
Published Aug 16, 2025 · Updated May 11, 2026
NULL pointer dereference in Linux kernel 6.15 through 6.15.7 allows local users to trigger a kernel warning through sched_ext callbacks. In SCX_CALL_OP and SCX_CALL_OP_RET, an unlocked callback supplies a NULL runqueue to update_locked_rq(), which executes __this_cpu_write() in preemptible context. Local low-privileged access is required, and panic-on-warning configurations turn the warning into a kernel panic rather than code execution.
Summary
What happened
NULL pointer dereference in Linux kernel 6.15 through 6.15.7 allows local users to trigger a kernel warning through sched_ext callbacks. In SCX_CALL_OP and SCX_CALL_OP_RET, an unlocked callback supplies a NULL runqueue to update_locked_rq(), which executes __this_cpu_write() in preemptible context. Local low-privileged access is required, and panic-on-warning configurations turn the warning into a kernel panic rather than code execution.
The record
- CVE
- CVE-2025-38522
- Published
- Aug 16, 2025
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-476, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 16, 2025CVE publishedPublication date reported by the CVE source.
- May 11, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=18853ba782bef65fc81ef2b3370382e5b479c5eb <237c43037b336e36a49eb9f2daac1c7719ec7f8b
- Affected versionversion=18853ba782bef65fc81ef2b3370382e5b479c5eb <e14fd98c6d66cb76694b12c05768e4f9e8c95664
- Affected versionversion=6.15
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
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Public exploit references
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Technologies
Your stack
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Your stack
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