CVE-2023-54255 sh: dma: Fix DMA channel offset calculation
A flaw in the Linux kernel SH DMA driver causes incorrect offset calculations, leading to kernel panics and denial of service on affected SuperH architectures.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-54255?
CVE-2023-54255 is a denial of service vulnerability in Linux, published on 30 Dec 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:
sh: dma: Fix DMA channel offset calculation
Various SoCs of the SH3, SH4 and SH4A family, which use this driver, feature a differing number of DMA channels, which can be distributed between up to two DMAC modules. The existing implementation fails to correctly accommodate for all those variations, resulting in wrong channel offset calculations and leading to kernel panics.
Rewrite dma_base_addr() in order to properly calculate channel offsets in a DMAC module. Fix dmaor_read_reg() and dmaor_write_reg(), so that the correct DMAC module base is selected for the DMAOR register.
Which versions are affected by CVE-2023-54255?
How do I fix CVE-2023-54255?
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-2023-54255 being exploited?
There is no known exploitation of CVE-2023-54255 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-54255, DEBIAN-CVE-2023-54255, GHSA-hvj9-4j33-rmxc, UBUNTU-CVE-2023-54255.