Bug 2507406 (CVE-2026-64532) - CVE-2026-64532 kernel: fs/ntfs3: bound NTFS_DE view.data_off in UpdateRecordData{Root,Allocation}
Summary: CVE-2026-64532 kernel: fs/ntfs3: bound NTFS_DE view.data_off in UpdateRecordD...
Keywords:
Status: NEW
Alias: CVE-2026-64532
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-07-27 08:01 UTC by OSIDB Bzimport
Modified: 2026-07-29 05:54 UTC (History)
2 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-07-27 08:01:46 UTC
In the Linux kernel, the following vulnerability has been resolved:

fs/ntfs3: bound NTFS_DE view.data_off in UpdateRecordData{Root,Allocation}

In do_action()'s UpdateRecordDataRoot (fslog.c:3489) and
UpdateRecordDataAllocation (fslog.c:3697) cases, the memmove
destination is `Add2Ptr(e, le16_to_cpu(e->view.data_off))`,
where e->view.data_off comes from an on-disk NTFS_DE inside
an INDEX_ROOT or INDEX_BUFFER.  Neither case validates
view.data_off + dlen against e->size; the existing
check_if_index_root / check_if_alloc_index helpers walk the
entry chain and validate the entry's offset, but not its
internal view fields.

The neighbouring read sites (e.g., fs/ntfs3/index.c when
iterating view entries) check view.data_off + view.data_size
<= e->size.  Apply the same bound at the two memmove sites.

Reproduced under UML+KASAN on mainline 8d90b09e6741 via
pr_warn-only probe instrumentation: with view.data_off forced
to 0xFFFC, the memmove writes 32 bytes past the end of the
NTFS_DE.

This is similar in shape to Pavitra Jha's 2026-05-02 patch
"fs/ntfs3: prevent oob in case UpdateRecordDataRoot"
(<20260502105008.21827-1-jhapavitra98>) which
proposes calling ntfs3_bad_de_range(); that helper does not
exist in mainline.  This patch uses inline checks.


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