CVE-2022-49654 net: dsa: qca8k: reset cpu port on MTU change
A Linux kernel driver bug causes a switch panic and network outage when MTU is changed, requiring a reset to recover.
- 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-2022-49654?
CVE-2022-49654 is a medium-severity denial of service vulnerability in Linux kernel, published on 26 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:
net: dsa: qca8k: reset cpu port on MTU change
It was discovered that the Documentation lacks of a fundamental detail on how to correctly change the MAX_FRAME_SIZE of the switch.
In fact if the MAX_FRAME_SIZE is changed while the cpu port is on, the switch panics and cease to send any packet. This cause the mgmt ethernet system to not receive any packet (the slow fallback still works) and makes the device not reachable. To recover from this a switch reset is required.
To correctly handle this, turn off the cpu ports before changing the MAX_FRAME_SIZE and turn on again after the value is applied.
Which versions are affected by CVE-2022-49654?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-49654?
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-2022-49654 being exploited?
There is no known exploitation of CVE-2022-49654 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-49654, GHSA-72j6-jfmc-mmvr, ROOT-OS-DEBIAN-11-CVE-2022-49654, UBUNTU-CVE-2022-49654.