Bug 2424898 (CVE-2025-68374)

Summary: CVE-2025-68374 kernel: md: fix rcu protection in md_wakeup_thread
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedKeywords: Security
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OS: Linux   
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A flaw was found in the Linux kernel's MD RAID subsystem. The RCU protection in md_wakeup_thread() is ineffective because the thread pointer is acquired before the rcu_read_lock() is taken. This ordering error means the pointer can be freed while still in use, leading to a potential use-after-free condition.
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Description OSIDB Bzimport 2025-12-24 11:04:41 UTC 
In the Linux kernel, the following vulnerability has been resolved:

md: fix rcu protection in md_wakeup_thread

We attempted to use RCU to protect the pointer 'thread', but directly
passed the value when calling md_wakeup_thread(). This means that the
RCU pointer has been acquired before rcu_read_lock(), which renders
rcu_read_lock() ineffective and could lead to a use-after-free.
Comment 1 Vipul Nair 2025-12-24 11:50:39 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025122402-CVE-2025-68374-560c@gregkh/T