Bug 2536318 (CVE-2026-92505)

Summary:	CVE-2026-92505 kernel: iommu/amd: Fix undefined behavior in devid_write debugfs function
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
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:
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Doc Text:	A flaw was found in the Linux kernel's iommu/amd component, specifically within the `devid_write` debugfs function. When the `for_each_pci_segment()` loop fails to find a matching segment, a pointer can reference an invalid memory location. Accessing this invalid memory can lead to undefined behavior, potentially causing system instability or a denial of service.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-09-17 17:20:53 UTC

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

iommu/amd: Fix undefined behavior in devid_write debugfs function

When for_each_pci_segment() loop completes without finding a matching
segment, the pci_seg pointer is not NULL but points to an invalid memory
location (the list head). Accessing pci_seg->id after the loop causes
undefined behavior.

Fix this by handling the successful case inside the loop and returning
-EINVAL after the loop if no matching segment is found.

Comment 1 gkamathe 2026-09-21 00:26:43 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-92505.mbox