Bug 2540334 (CVE-2026-93260)

Summary:	CVE-2026-93260 kernel: powerpc/xive: propagate IPI init errors to prevent 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:	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. When initialization of inter-processor interrupts fails within the PowerPC External Interrupt Virtualization Engine (XIVE), the system ignores the failure after freeing allocated memory structures. This leads to a use-after-free condition when subsequent setup code attempts to access the released data, resulting in memory corruption. An attacker or environment triggering an allocation failure could exploit this flaw to cause a Denial of Service (DoS) via a system crash or potentially execute arbitrary code.	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 2026-09-24 16:21:54 UTC

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

powerpc/xive: propagate IPI init errors to prevent use-after-free

When xive_init_ipis() fails (e.g. irq_domain_alloc_irqs() fails),
the error path frees the global xive_ipis array.  However,
xive_smp_probe() previously ignored this failure and proceeded to
call xive_setup_cpu_ipi(), which dereferences the already-freed
xive_ipis pointer -- a use-after-free.

Now that xive_smp_probe() returns int (previous patch), propagate
the error from xive_init_ipis() and xive_setup_cpu_ipi() through
xive_smp_probe().  Check the return value in both pnv_smp_probe()
and pSeries_smp_probe() so that IPI setup is aborted cleanly on
failure, avoiding the use-after-free.

Comment 1 gkamathe 2026-09-28 10:47:19 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-93260.mbox