# CVE-2026-43127: ntfs3: fix circular locking dependency in run_unpack_ex CVE-2026-43127 is fixed in 23 products on 1 platform, first by ALAS2023-2026-1702, released May 11, 2026. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2026-43127 - Priority: Routine - CVSS: 5.5 (Moderate) - EPSS: 0.0012 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: May 6, 2026 - Weakness: Improper Locking - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-43127 ## 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. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool6.18 amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | bpftool6.18-debuginfo amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel-livepatch-6.18.16-18.222 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18 amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-debuginfo amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-debuginfo-common-aarch64 amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-debuginfo-common-x86_64 amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-devel amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-headers amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-libbpf amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-libbpf-debuginfo amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-libbpf-devel amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-libbpf-static amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-modules-extra amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-modules-extra-common amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-tools amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-tools-debuginfo amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | kernel6.18-tools-devel amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.115-2 | [DEBIAN-CVE-2026-43127](https://patchblox.com/security/data/fix/linux/debian-cve-2026-43127.md) | May 15, 2026 | | Linux | linux Debian 14 | 6.19.6-1 | [DEBIAN-CVE-2026-43127](https://patchblox.com/security/data/fix/linux/debian-cve-2026-43127.md) | May 15, 2026 | | Linux | perf6.18 amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | perf6.18-debuginfo amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | python3-perf6.18 amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | | Linux | python3-perf6.18-debuginfo amzn 2023 | 1:6.18.16-18.222.amzn2023 | [ALAS2023-2026-1702](https://patchblox.com/security/data/fix/linux/alas2023-2026-1702.md) | May 11, 2026 | --- Data as of 2026-11-09T07:25:28Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.