CVE-2024-26778 fbdev: savage: Error out if pixclock equals zero
A local attacker can cause a kernel crash via divide-by-zero in the savage framebuffer driver by passing zero pixclock values.
- 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-2024-26778?
CVE-2024-26778 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 3 Apr 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:
fbdev: savage: Error out if pixclock equals zero
The userspace program could pass any values to the driver through ioctl() interface. If the driver doesn't check the value of pixclock, it may cause divide-by-zero error.
Although pixclock is checked in savagefb_decode_var(), but it is not checked properly in savagefb_probe(). Fix this by checking whether pixclock is zero in the function savagefb_check_var() before info->var.pixclock is used as the divisor.
This is similar to CVE-2022-3061 in i740fb which was fixed by commit 15cf0b8.
Weakness: CWE-369
Which versions are affected by CVE-2024-26778?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2024-26778?
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-2024-26778 being exploited?
There is no known exploitation of CVE-2024-26778 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as BELL-CVE-2024-26778, DEBIAN-CVE-2024-26778, GHSA-4m6c-v88j-qqxh, UBUNTU-CVE-2024-26778.