CVE-2026-74277 iommu/dma-iommu: Fix wrong scatterlist length assignment in P2PDMA path
A typo in the Linux kernel's IOMMU DMA mapping causes corrupted DMA lengths for P2PDMA, potentially leading to system instability or 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-2026-74277?
CVE-2026-74277 is a high-severity vulnerability in Linux, published on 15 Aug 2026. 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:
iommu/dma-iommu: Fix wrong scatterlist length assignment in P2PDMA path
In iommu_dma_map_sg(), when handling PCI P2PDMA cases, the DMA length of the current scatterlist segment `s` is incorrectly assigned from the head entry `sg->length` instead of the current entry `s->length`.
This typo causes all P2PDMA segments in the scatterlist to inherit the length of the first segment, leading to corrupted DMA lengths for multi- segment scatterlists.
Fix this by using `s->length` instead of `sg->length`.
Which versions are affected by CVE-2026-74277?
How do I fix CVE-2026-74277?
Apply the vendor's patch.
Is CVE-2026-74277 being exploited?
There is no known exploitation of CVE-2026-74277 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-74277, DEBIAN-CVE-2026-74277, GHSA-v74x-xvfc-h3j3, UBUNTU-CVE-2026-74277.