CVE-2025-21810 driver core: class: Fix wild pointer dereferences in API class_dev_iter_next()

What is CVE-2025-21810?

CVE-2025-21810 is a high-severity vulnerability in Linux kernel, published on 27 Feb 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

In the Linux kernel, the following vulnerability has been resolved:

driver core: class: Fix wild pointer dereferences in API class_dev_iter_next()

There are a potential wild pointer dereferences issue regarding APIs class_dev_iter_(init|next|exit)(), as explained by below typical usage:

// All members of @iter are wild pointers. struct class_dev_iter iter;

// class_dev_iter_init(@iter, @class, ...) checks parameter @class for // potential class_to_subsys() error, and it returns void type and does // not initialize its output parameter @iter, so caller can not detect // the error and continues to invoke class_dev_iter_next(@iter) even if // @iter still contains wild pointers. class_dev_iter_init(&iter, ...);

// Dereference these wild pointers in @iter here once suffer the error. while (dev = class_dev_iter_next(&iter)) { ... };

// Also dereference these wild pointers here. class_dev_iter_exit(&iter);

Actually, all callers of these APIs have such usage pattern in kernel tree. Fix by: - Initialize output parameter @iter by memset() in class_dev_iter_init() and give callers prompt by pr_crit() for the error. - Check if @iter is valid in class_dev_iter_next().

Weakness: CWE-476

Which versions are affected by CVE-2025-21810?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2025-21810?

Apply the vendor's patch.

Is CVE-2025-21810 being exploited?

There is no known exploitation of CVE-2025-21810 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2025-21810, DEBIAN-CVE-2025-21810, GHSA-p7wm-885p-3rmg, ROOT-OS-UBUNTU-2404-CVE-2025-21810, UBUNTU-CVE-2025-21810.