Bug 2516291 (CVE-2026-72199) - CVE-2026-72199 kernel: ntfs: validate resident index root values on lookup
Summary: CVE-2026-72199 kernel: ntfs: validate resident index root values on lookup
Keywords:
Status: NEW
Alias: CVE-2026-72199
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-15 06:04 UTC by OSIDB Bzimport
Modified: 2026-08-18 05:38 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


Attachments (Terms of Use)

Description OSIDB Bzimport 2026-08-15 06:04:48 UTC
In the Linux kernel, the following vulnerability has been resolved:

ntfs: validate resident index root values on lookup

Resident $INDEX_ROOT values carry index header fields that callers
consume after lookup. Some callers already validate parts of the layout
before walking entries, but those checks are scattered and do not cover
all root header invariants, such as entries_offset alignment and lower
bound, index_length, and allocated_size consistency.

The resident root resize paths now keep these header fields consistent
while the value size changes: ntfs_ir_truncate() lowers
index.allocated_size before shrinking the resident value, and
ntfs_ir_reparent() grows the resident value before publishing a larger
root header. Lookup-time validation can therefore cover these invariants
without tripping over the driver's own resize paths.

Add $INDEX_ROOT to the minimum resident value size table and validate the
resident index header fields before returning the attribute from lookup.
Require 8-byte aligned index header fields, a sane entries_offset, an
index_length within allocated_size, allocated_size within the resident
value, and enough entry space for at least an index entry header.

The shared validator already rejects non-resident records for
resident-only attribute types, including $INDEX_ROOT.


Note You need to log in before you can comment on or make changes to this bug.