Bug 2482107 (CVE-2026-45880)

Summary:	CVE-2026-45880 kernel: PCI/P2PDMA: Release per-CPU pgmap ref when vm_insert_page() fails
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
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Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's PCI/P2PDMA subsystem. When the `vm_insert_page()` function fails during memory allocation, the system does not properly release a per-CPU reference for the page map. This oversight can lead to a resource leak, causing the `memunmap_pages()` function to hang indefinitely when attempting to remove a PCI device. Consequently, a local attacker could potentially trigger a Denial of Service (DoS) condition, making the system unresponsive.	Story Points:	---
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Documentation:	---	CRM:
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-05-27 15:11:39 UTC

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

PCI/P2PDMA: Release per-CPU pgmap ref when vm_insert_page() fails

When vm_insert_page() fails in p2pmem_alloc_mmap(), p2pmem_alloc_mmap()
doesn't invoke percpu_ref_put() to free the per-CPU ref of pgmap acquired
after gen_pool_alloc_owner(), and memunmap_pages() will hang forever when
trying to remove the PCI device.

Fix it by adding the missed percpu_ref_put().

Comment 1 Keith Grant 2026-05-28 03:20:16 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026052715-CVE-2026-45880-4a0d@gregkh/T