Bug 2536249 (CVE-2026-93170)

Summary:	CVE-2026-93170 kernel: dmaengine: xilinx_dma: Fix channel idle state management in AXIDMA and MCDMA interrupt handlers
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, 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 Xilinx DMA (Direct Memory Access) engine. A race condition in the AXIDMA and MCDMA interrupt handlers can cause the DMA channel to be incorrectly marked as idle while data transfer descriptors are still being processed. This premature idle state can lead to spurious transfer attempts, potentially resulting in descriptor corruption or missed data completions, which may impact system stability and data integrity.	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 2026-09-17 17:07:24 UTC

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

dmaengine: xilinx_dma: Fix channel idle state management in AXIDMA and MCDMA interrupt handlers

Fix a race condition in AXIDMA and MCDMA irq handlers where the channel
could be incorrectly marked as idle and attempt spurious transfers when
descriptors are still being processed.

The issue occurs when:
1. Multiple descriptors are queued and active.
2. An interrupt fires after completing some descriptors.
3. xilinx_dma_complete_descriptor() moves completed descriptors to
done_list.
4. Channel is marked idle and start_transfer() is called even though
   active_list still contains unprocessed descriptors.
5. This leads to premature transfer attempts and potential descriptor
   corruption or missed completions.

Only mark the channel as idle and start new transfers when the active list
is actually empty, ensuring proper channel state management and avoiding
spurious transfer attempts.

Comment 1 gkamathe 2026-09-18 05:13:45 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93170.mbox