CVE-2025-38704: rcu/nocb: Fix possible invalid rdp's->nocb_cb_kthread pointer access
In the Linux kernel, the following vulnerability has been resolved:
rcu/nocb: Fix possible invalid rdp's->nocbcbkthread pointer access
In the preparation stage of CPU online, if the corresponding the rdp's->nocbcbkthread does not exist, will be created, there is a situation where the rdp's rcuop kthreads creation fails, and then de-offload this CPU's rdp, does not assign this CPU's rdp->nocbcbkthread pointer, but this rdp's->nocbgprdp and rdp's->rdpgp->nocbgpkthread is still valid.
This will cause the subsequent re-offload operation of this offline CPU, which will pass the conditional check and the kthreadunpark() will access invalid rdp's->nocbcbkthread pointer.
This commit therefore use rdp's->nocbgpkthread instead of rdpgp's->nocbgpkthread for safety check.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2025-38704?
CVE-2025-38704 has a moderate severity rating as it pertains to a potential access issue within the Linux kernel's rcu/nocb functionalities.
How do I fix CVE-2025-38704?
To resolve CVE-2025-38704, ensure you update to the latest version of the Linux kernel where the vulnerability has been addressed.
What systems are affected by CVE-2025-38704?
CVE-2025-38704 affects various systems running the Linux kernel that utilize the rcu/nocb features.
What are the potential impacts of CVE-2025-38704?
The potential impacts of CVE-2025-38704 include system instability and unauthorized access due to improper handling of the nocb_cb_kthread pointer.
Is it possible to exploit CVE-2025-38704 remotely?
Exploitation of CVE-2025-38704 typically requires local access to the affected system, which limits its potential for remote exploitation.