Bug 2516281 (CVE-2026-72198)

Summary: CVE-2026-72198 kernel: ntfs: reject non-resident records for resident-only attributes
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: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's NTFS file system driver. This vulnerability arises from the incorrect handling of non-resident records for attributes that are expected to be resident. This can lead to 'union confusion paths' where the kernel attempts to read data from an incorrect memory location or misinterprets attribute values. While the direct impact is not explicitly detailed, such issues can typically lead to system instability or a denial of service.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-08-15 06:04:19 UTC
In the Linux kernel, the following vulnerability has been resolved:

ntfs: reject non-resident records for resident-only attributes

The shared lookup-time attribute validator rejects non-resident
$FILE_NAME and $VOLUME_NAME records because their formats require
resident values and callers handle returned records as resident
attributes. Other resident-only attribute types still pass through the
generic non-resident mapping-pairs checks.

That leaves real resident/non-resident union confusion paths. Inode load
looks up $STANDARD_INFORMATION and then reads data.resident.value_offset
without checking a->non_resident. ntfs_inode_sync_standard_information()
does the same when updating the standard information value.
ntfs_write_volume_flags() also looks up $VOLUME_INFORMATION and reads
data.resident.value_offset directly. $INDEX_ROOT callers in dir.c and
index.c depend on the same lookup contract before consuming the resident
index root value.

Reject non-resident records for all resident-only attribute types in the
shared validator. Keep the existing $FILE_NAME and $VOLUME_NAME behavior,
but factor it through a helper and extend it to
$STANDARD_INFORMATION, $OBJECT_ID, $VOLUME_INFORMATION, $INDEX_ROOT, and
$EA_INFORMATION. For $OBJECT_ID and $EA_INFORMATION this is contract
hardening for resident-only formats; this patch only rejects the
non-resident form and does not add new resident value validation for
those types.