CVE-2026-53029

fs/ntfs3: prevent uninitialized lcn caused by zero len

MEDIUM
5.5
CVSS Score
Published: June 24, 2026 at 04:29 PM UTC
Updated: July 15, 2026 at 02:54 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.1%

Description

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: prevent uninitialized lcn caused by zero len syzbot reported a uninit-value in ntfs_iomap_begin [1]. Since runs was not touched yet, run_lookup_entry() immediately fails and returns false, which makes the value of "*len" 0. Simultaneously, the new value and err value are also 0, causing the logic in attr_data_get_block_locked() to jump directly to ok, ultimately resulting in *lcn being triggered before it is set [1]. In ntfs_iomap_begin(), the check for a 0 value in clen is moved forward to before updating lcn to avoid this [1]. [1] BUG: KMSAN: uninit-value in ntfs_iomap_begin+0x8c0/0x1460 fs/ntfs3/inode.c:825 ntfs_iomap_begin+0x8c0/0x1460 fs/ntfs3/inode.c:825 iomap_iter+0x9b7/0x1540 fs/iomap/iter.c:110 Local variable lcn created at: ntfs_iomap_begin+0x15d/0x1460 fs/ntfs3/inode.c:786

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

7.0 ≤ v < 7.0.107.0 ≤ v < 7.110d7c95af043b45a85dc738c3271bf760ff3577e7.0
Vendor states this is fixed in 485f750cac3d8bdf5552a0e3d79ce5e3a03ece49 (fixed)
Vendor states this is fixed in e98266e823a1fa06fe6499df61aeaac2fd6f7a49 (fixed)
Vendor states this is fixed in 7.0 (unaffected)
Vendor states this is fixed in 7.0.10 (unaffected)
Vendor states this is fixed in 7.1 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-908

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