Bug 2516293 (CVE-2026-72476)

Summary:	CVE-2026-72476 kernel: dmaengine: Fix possible use after free
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 dmaengine component of the Linux kernel. This flaw occurs in the `dma_release_channel()` function due to an incorrect order of operations, where a channel's reference count is decremented before verifying if the device is still in use. This can lead to a use-after-free vulnerability, potentially causing system instability or a denial of service.	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 2026-08-15 06:04:57 UTC

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

dmaengine: Fix possible use after free

In dma_release_channel(), check chan->device->privatecnt after call
dma_chan_put(). However, dma_chan_put() call dma_device_put() which could
release the last reference of the device if the DMA provider is already
gone and hence free it.

Fixes it by moving dma_chan_put() after the check.

Comment 1 gkamathe 2026-08-19 13:24:42 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081536-CVE-2026-72476-d0b7@gregkh/T