CVE-2024-38618 ALSA: timer: Set lower bound of start tick time
A local attacker can cause a system hang or RCU stall by setting an extremely small ALSA timer tick interval, requiring a kernel patch to enforce a minimum limit.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-38618?
CVE-2024-38618 is a medium-severity denial of service vulnerability in Linux kernel, published on 19 Jun 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ALSA: timer: Set lower bound of start tick time
Currently ALSA timer doesn't have the lower limit of the start tick time, and it allows a very small size, e.g. 1 tick with 1ns resolution for hrtimer. Such a situation may lead to an unexpected RCU stall, where the callback repeatedly queuing the expire update, as reported by fuzzer.
This patch introduces a sanity check of the timer start tick time, so that the system returns an error when a too small start size is set. As of this patch, the lower limit is hard-coded to 100us, which is small enough but can still work somehow.
Which versions are affected by CVE-2024-38618?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-38618?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2024-38618 being exploited?
There is no known exploitation of CVE-2024-38618 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-38618, DEBIAN-CVE-2024-38618, GHSA-2hfc-xmh6-q9f9, UBUNTU-CVE-2024-38618.