CVE-2026-64280: fpga: dfl-afu: validate DMA mapping length in afu_dma_map_region()
In the Linux kernel, the following vulnerability has been resolved:
fpga: dfl-afu: validate DMA mapping length in afudmamapregion()
afuioctldmamap() accepts a 64-bit length from userspace via DFLFPGAPORTDMAMAP ioctl without an upper bound check. The value is passed to afudmapinpages() where npages is derived as length >> PAGESHIFT and passed to pinuserpagesfast() which takes int nrpages, causing implicit truncation if length is very large.
Validate map.length at the ioctl entry point before calling afudmamapregion(), rejecting values whose page count exceeds INTMAX.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
At the fpga: dfl-afu ioctl entry point, validate map.length before calling afu_dma_map_region(). Reject user-supplied lengths where the derived page count exceeds the afu_ioctl_dma_map() limit to prevent implicit truncation (map.length passed via fpga: dfl-afu and then into npages = length >> PAGE_SHIFT for pin_user_pages_fast()).
Linux kernel (fpga: dfl-afu) DMA mapping length validation = Validate map.length at the ioctl entry point before calling afu_dma_map_region(); reject values whose page count exceeds afu_ioctl_dma_map() limits
Event History
Frequently Asked Questions
What is the severity of CVE-2026-64280?
CVE-2026-64280 has a high severity rating of 8.8 according to the CVSS 3.1 scoring.
How do I fix CVE-2026-64280?
To fix CVE-2026-64280, update to the patched version of the Linux kernel that addresses the vulnerability.
What systems are affected by CVE-2026-64280?
CVE-2026-64280 affects systems running the Linux kernel that utilize the DFL_FPGA_PORT_DMA_MAP ioctl.
What type of vulnerability is CVE-2026-64280?
CVE-2026-64280 is a denial-of-service vulnerability related to improper validation of DMA mapping lengths in the Linux kernel.
When was CVE-2026-64280 published?
CVE-2026-64280 was published on July 25, 2026.