Bug 2507191 (CVE-2026-64372)

Summary: CVE-2026-64372 kernel: cpufreq: pcc: fix use-after-free and double free in _OSC evaluation
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel's cpufreq subsystem. This vulnerability, a use-after-free and double-free error, occurs during the two-phase _OSC negotiation in the `pcc_cpufreq_do_osc()` function. A local attacker could exploit this memory corruption to cause a denial of service (DoS) or potentially achieve privilege escalation.
 Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-07-25 10:09:49 UTC 
In the Linux kernel, the following vulnerability has been resolved:

cpufreq: pcc: fix use-after-free and double free in _OSC evaluation

pcc_cpufreq_do_osc() calls acpi_evaluate_object() twice for the
two-phase _OSC negotiation. Between the two calls it freed
output.pointer but left output.length unchanged. Since
acpi_evaluate_object() treats a non-zero length with a non-NULL
pointer as an existing buffer to write into, the second call wrote
into freed memory (use-after-free). The subsequent kfree(output.pointer)
at out_free then freed the same pointer a second time (double free).

Reset output.pointer to NULL and output.length to ACPI_ALLOCATE_BUFFER
after freeing the first result, so ACPICA allocates a fresh buffer for
each phase independently.
Comment 1 TEJ RATHI 2026-07-29 11:12:33 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026072523-CVE-2026-64372-794b@gregkh/T