CVE-2024-27027 dpll: fix dpll_xa_ref_*_del() for multiple registrations

Medium 5.5 Published Updated

A logic error in the Linux kernel DPLL subsystem causes warnings and potential crashes when multiple registrations occur, leading to denial of service.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Local or same network only
Victim action needed
Not needed
Fix
Available

What is CVE-2024-27027?

CVE-2024-27027 is a medium-severity vulnerability in Linux kernel, published on 1 May 2024. 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:

dpll: fix dpll_xa_ref_*_del() for multiple registrations

Currently, if there are multiple registrations of the same pin on the same dpll device, following warnings are observed: WARNING: CPU: 5 PID: 2212 at drivers/dpll/dpll_core.c:143 dpll_xa_ref_pin_del.isra.0+0x21e/0x230 WARNING: CPU: 5 PID: 2212 at drivers/dpll/dpll_core.c:223 __dpll_pin_unregister+0x2b3/0x2c0

The problem is, that in both dpll_xa_ref_dpll_del() and dpll_xa_ref_pin_del() registration is only removed from list in case the reference count drops to zero. That is wrong, the registration has to be removed always.

To fix this, remove the registration from the list and free it unconditionally, instead of doing it only when the ref reference counter reaches zero.

Which versions are affected by CVE-2024-27027?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2024-27027?

Apply the vendor's patch.

Is CVE-2024-27027 being exploited?

There is no known exploitation of CVE-2024-27027 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as BELL-CVE-2024-27027, DEBIAN-CVE-2024-27027, GHSA-gwjw-xj3g-wq7h, UBUNTU-CVE-2024-27027.

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