Bug 2536794 (CVE-2026-90134)

Summary:	CVE-2026-90134 kernel: ntfs: fix kmap_local_page() usage in compress
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
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 NTFS filesystem driver. This vulnerability arises from incorrect handling of memory page mappings in compressed input/output (I/O) operations. An attacker could potentially exploit this flaw by interacting with the NTFS driver, leading to system instability or a denial of service (DoS).	Story Points:	---
Clone Of:		Environment:
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Regression:	---	Mount Type:	---
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Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-09-17 19:34:03 UTC

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

ntfs: fix kmap_local_page() usage in compress

Several compressed I/O paths discard the address returned by
kmap_local_page() and later access or unmap the page using page_address().
This is invalid for highmem pages, and local mappings must also be unmapped
using the address returned by kmap_local_page().

Map each destination page in ntfs_decompress() only while producing the
current sub-block. Use memcpy_from_page(), memcpy_to_page(), and
memzero_page() for the other page accesses. Remove unnecessary local
mappings from ntfs_write_cb(), where pages are accessed through the vmap()
mapping.

Comment 1 Keith Grant 2026-09-23 15:11:01 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-90134.mbox