Bug 2536438 (CVE-2026-90217)

Summary:	CVE-2026-90217 kernel: bpf: Compare iterator types during state pruning
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 Berkeley Packet Filter (BPF) verifier. The verifier, responsible for ensuring the safety of BPF programs, incorrectly compared iterator types during state pruning. This discrepancy between MEM_RCU and PTR_UNTRUSTED states could allow the verifier to prune an unsafe execution path, potentially leading to a security bypass.	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 17:50:34 UTC

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

bpf: Compare iterator types during state pruning

An iterator stack slot can be MEM_RCU or PTR_UNTRUSTED. These states
must not be equal, or the verifier can prune an unsafe path.

Compare the pointer type for STACK_ITER slots.

Comment 1 Mauro Matteo Cascella 2026-09-24 12:52:04 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-90217.mbox