Bug 2507192 (CVE-2026-64280)

Summary:	CVE-2026-64280 kernel: fpga: dfl-afu: validate DMA mapping length in afu_dma_map_region()
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's `dfl-afu` FPGA driver. A local user could exploit this vulnerability by providing an excessively large length value during Direct Memory Access (DMA) mapping operations. The system incorrectly truncates this value, leading to memory corruption. This could allow a local attacker to gain elevated privileges or execute arbitrary code on the system.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-07-25 10:09:51 UTC

In the Linux kernel, the following vulnerability has been resolved:

fpga: dfl-afu: validate DMA mapping length in afu_dma_map_region()

afu_ioctl_dma_map() accepts a 64-bit length from userspace via
DFL_FPGA_PORT_DMA_MAP ioctl without an upper bound check. The value
is passed to afu_dma_pin_pages() where npages is derived as
length >> PAGE_SHIFT and passed to pin_user_pages_fast() which takes
int nr_pages, causing implicit truncation if length is very large.

Validate map.length at the ioctl entry point before calling
afu_dma_map_region(), rejecting values whose page count exceeds
INT_MAX.

Comment 1 TEJ RATHI 2026-07-29 10:59:43 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026072502-CVE-2026-64280-0e16@gregkh/T