CVE-2026-43127 — MEDIUM (5.5)

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: ntfs3: fix circular locking dependency in run_unpack_ex Syzbot reported a circular locking dependency between wnd->rw_lock (sbi->used.bitmap) and ni->file.run_lock. The deadlock scenario: 1. ntfs_extend_mft() takes ni->file.run_lock then wnd->rw_lock. 2. run_unpack_ex() takes wnd->rw_lock then tries to acquire ni->file.run_lock inside ntfs_refresh_zone(). This creates an AB-BA deadlock. Fix this by using down_read_trylock() instead of down_read() when acquiring run_lock in run_unpack_ex(). If the lock is contended, skip ntfs_refresh_zone() - the MFT zone will be refreshed on the next MFT operation. This breaks the circular dependency since we never block waiting for run_lock while holding wnd->rw_lock.

CVSS Score

5.5

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

NONE

Availability

HIGH

Affected Products

Vendor	Product	Versions
Linux	Linux Kernel	>= 6.6.66, < 6.18.16

Related Weaknesses (CWE)

CWE-667

References

FAQ

What is CVE-2026-43127?

CVE-2026-43127 is a vulnerability with a CVSS score of 5.5 (MEDIUM). In the Linux kernel, the following vulnerability has been resolved: ntfs3: fix circular locking dependency in run_unpack_ex Syzbot reported a circular locking dependency between wnd->rw_lock (sbi->u...

How severe is CVE-2026-43127?

CVE-2026-43127 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-43127?

Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.