Bug 2541260 (CVE-2026-97990)

Summary:	CVE-2026-97990 kernel: vdpa_sim_net: check TX pull result before RX copy
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:	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 vHost Data Path Acceleration (vDPA) network simulator driver. When a packet transmission pull operation fails, a negative error code is improperly treated as an unsigned value, resulting in an excessively large buffer length during receive processing. A local user could exploit this flaw to cause out-of-bounds memory access, leading to a kernel crash and Denial of Service (DoS).	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 2026-09-25 11:12:20 UTC

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

vdpa_sim_net: check TX pull result before RX copy

vringh_iov_pull_iotlb() returns a signed byte count.  A failed TX pull is
currently added to the unsigned byte counter and then passed as a size_t
length to receive_filter() and vringh_iov_push_iotlb().  A negative error
can therefore become a large length in the RX path.

Handle non-positive pull results before every length use.  Count the TX
error and complete the consumed TX descriptor with zero bytes.

I found this bug myself, though the patch was written with AI assistance.

Comment 1 gkamathe 2026-09-30 08:29:49 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97990.mbox