Bug 2562655 (CVE-2026-99101)

Summary: CVE-2026-99101 kernel: ntfs: move attribute payload before shrinking its record
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: 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   
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Doc Text:
A flaw was found in the Linux kernel's NTFS file system driver. When clearing compression or sparse file flags, the driver shrinks an internal attribute record before shifting its contents, which overwrites part of the record with adjacent data. A local user could exploit this behavior by changing file attributes to cause file system corruption and data integrity issues.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-10-28 10:44:21 UTC 
In the Linux kernel, the following vulnerability has been resolved:

ntfs: move attribute payload before shrinking its record

ntfs_new_attr_flags() resizes the non-resident attribute record before
moving its name and mapping pairs to their shorter-header offsets when
compression or sparse state is cleared.

Shrinking the record first moves the following attribute over the tail of
the old record. The subsequent memmove() therefore copies bytes from that
following attribute instead of the old mapping pairs. Re-enabling
compression on an empty file persists those bytes as a malformed mapping
pairs array, which ntfsck reports as a missing or invalid run length.

Move the payload before shrinking the record, while retaining the existing
resize-before-move ordering when growing it.