CVE-2025-40346

CVE-2025-40346 is a security vulnerability that is still awaiting full analysis and scoring. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Description

In the Linux kernel, the following vulnerability has been resolved: arch_topology: Fix incorrect error check in topology_parse_cpu_capacity() Fix incorrect use of PTR_ERR_OR_ZERO() in topology_parse_cpu_capacity() which causes the code to proceed with NULL clock pointers. The current logic uses !PTR_ERR_OR_ZERO(cpu_clk) which evaluates to true for both valid pointers and NULL, leading to potential NULL pointer dereference in clk_get_rate(). Per include/linux/err.h documentation, PTR_ERR_OR_ZERO(ptr) returns: "The error code within @ptr if it is an error pointer; 0 otherwise." This means PTR_ERR_OR_ZERO() returns 0 for both valid pointers AND NULL pointers. Therefore !PTR_ERR_OR_ZERO(cpu_clk) evaluates to true (proceed) when cpu_clk is either valid or NULL, causing clk_get_rate(NULL) to be called when of_clk_get() returns NULL. Replace with !IS_ERR_OR_NULL(cpu_clk) which only proceeds for valid pointers, preventing potential NULL pointer dereference in clk_get_rate().

Frequently asked questions

What is CVE-2025-40346?
In the Linux kernel, the following vulnerability has been resolved: arch_topology: Fix incorrect error check in topology_parse_cpu_capacity() Fix incorrect use of PTR_ERR_OR_ZERO() in topology_parse_cpu_capacity() which causes the code to proceed with NULL clock pointers. The current logic uses !PTR_ERR_OR_ZERO(cpu_clk) which evaluates to true for both valid pointers and NULL, leading to potential NULL pointer dereference in clk_get_rate(). Per include/linux/err.h documentation, PTR_ERR_OR_ZERO(ptr) returns: "The error code within @ptr if it is an error pointer; 0 otherwise." This means PTR_ERR_OR_ZERO() returns 0 for both valid pointers AND NULL pointers. Therefore !PTR_ERR_OR_ZERO(cpu_clk) evaluates to true (proceed) when cpu_clk is either valid or NULL, causing clk_get_rate(NULL) to be called when of_clk_get() returns NULL. Replace with !IS_ERR_OR_NULL(cpu_clk) which only proceeds for valid pointers, preventing potential NULL pointer dereference in clk_get_rate().
Is CVE-2025-40346 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-40346?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-40346 have an EU (EUVD) identifier?
Yes. CVE-2025-40346 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-203641.
When was CVE-2025-40346 published?
CVE-2025-40346 was published on 2025-12-16 and last updated on 2026-06-17.

References