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

fs/ntfs3: fix missing run load for vcn0 in attr_data_get_block_locked()

When a compressed or sparse attribute has its clusters frame-aligned,
vcn is rounded down to the frame start using cmask, which can result
in vcn != vcn0. In this case, vcn and vcn0 may reside in different
attribute segments.

The code already handles the case where vcn is in a different segment
by loading its runs before allocation. However, it fails to load runs
for vcn0 when vcn0 resides in a different segment than vcn. This causes
run_lookup_entry() to return SPARSE_LCN for vcn0 since its segment was
never loaded into the in-memory run list, triggering the WARN_ON(1).

Fix this by adding a missing check for vcn0 after the existing vcn
segment check. If vcn0 falls outside the current segment range
[svcn, evcn1), find and load the attribute segment containing vcn0
before performing the run lookup.

The following scenario triggers the bug:
attr_data_get_block_locked()
vcn = vcn0 & cmask <- vcn != vcn0 after frame alignment
load runs for vcn segment <- vcn0 segment not loaded!
attr_allocate_clusters() <- allocation succeeds
run_lookup_entry(vcn0) <- vcn0 not in run -> SPARSE_LCN
WARN_ON(1) <- bug fires here!

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Source ID Title
Debian DSA Debian DSA DSA-6393-1 linux security update
Ubuntu USN Ubuntu USN USN-8566-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8568-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8569-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-8593-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8603-1 Linux kernel (Azure) vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 24 Jul 2026 18:30:00 +0000


Sat, 18 Jul 2026 15:30:00 +0000


Fri, 26 Jun 2026 05:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-665

Fri, 26 Jun 2026 00:15:00 +0000


Wed, 24 Jun 2026 19:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-665

Wed, 24 Jun 2026 17:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: fix missing run load for vcn0 in attr_data_get_block_locked() When a compressed or sparse attribute has its clusters frame-aligned, vcn is rounded down to the frame start using cmask, which can result in vcn != vcn0. In this case, vcn and vcn0 may reside in different attribute segments. The code already handles the case where vcn is in a different segment by loading its runs before allocation. However, it fails to load runs for vcn0 when vcn0 resides in a different segment than vcn. This causes run_lookup_entry() to return SPARSE_LCN for vcn0 since its segment was never loaded into the in-memory run list, triggering the WARN_ON(1). Fix this by adding a missing check for vcn0 after the existing vcn segment check. If vcn0 falls outside the current segment range [svcn, evcn1), find and load the attribute segment containing vcn0 before performing the run lookup. The following scenario triggers the bug: attr_data_get_block_locked() vcn = vcn0 & cmask <- vcn != vcn0 after frame alignment load runs for vcn segment <- vcn0 segment not loaded! attr_allocate_clusters() <- allocation succeeds run_lookup_entry(vcn0) <- vcn0 not in run -> SPARSE_LCN WARN_ON(1) <- bug fires here!
Title fs/ntfs3: fix missing run load for vcn0 in attr_data_get_block_locked()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-07-24T14:33:47.674Z

Reserved: 2026-06-09T07:44:35.379Z

Link: CVE-2026-53027

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

Severity :

Publid Date: 2026-06-24T00:00:00Z

Links: CVE-2026-53027 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-06-26T06:30:17Z

Weaknesses