# CVE-2026-97558: smb: client: fix cifsFileInfo reference leak in deferred close

CVE-2026-97558 is fixed in 52 products on 1 platform, first by DEBIAN-CVE-2026-97558, released October 2, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-97558
- Priority: High
- CVSS: 7.1 (Moderate)
- EPSS: 0.0023
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 25, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-97558

## Description

In the Linux kernel, the following vulnerability has been resolved:  smb: client: fix cifsFileInfo reference leak in deferred close  When cifs_close() defers a close, it hands the cifsFileInfo reference of the closing struct file to the queued work. Each execution of smb2_deferred_work_close() drops one such reference.  deferred_close_scheduled can be false while the work is pending: the workqueue clears PENDING when the callback starts to run, before the callback clears the flag under deferred_lock. A close in that interval requeues the running work, and the callback then clears the flag, leaving the requeued work pending with the flag down. A later cifs_open() can reuse the handle and its cifs_close() reaches the same branch: queue_delayed_work() fails because the work is still pending, but cifs_close() returns without dropping the closing file's reference. The cifsFileInfo count stays pinned and its tlink, dentry and server handle are leaked.  Check the return value and hand off the reference only when work was actually queued. Otherwise, use the shared _cifsFileInfo_put(), like the mod_delayed_work() branch above: the pending execution already owns its reference.  This issue was found by an in-house static analysis tool.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | bpftool6.12 amzn 2023 | 1:6.12.113-138.209.amzn2023 | [ALAS2023-2026-3335](https://patchblox.com/security/data/fix/linux/alas2023-2026-3335.md) | Nov 7, 2026 |
| Linux | bpftool6.12-debuginfo amzn 2023 | 1:6.12.113-138.209.amzn2023 | [ALAS2023-2026-3335](https://patchblox.com/security/data/fix/linux/alas2023-2026-3335.md) | Nov 7, 2026 |
| Linux | bpftool6.18 amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 |
| Linux | bpftool6.18-debuginfo amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 |
| Linux | dtb-aarch64 opensuse-leap 16.0 | 6.12.0-160000.40.1 | [OPENSUSE-SU-2026:22167-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22167-1.md) | Nov 7, 2026 |
| Linux | kernel-64kb opensuse-leap 16.0 | 6.12.0-160000.40.1 | [OPENSUSE-SU-2026:22167-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22167-1.md) | Nov 7, 2026 |
| Linux | kernel-64kb sles 16.0 | 6.12.0-160000.40.1 | [SUSE-SU-2026:24446-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24446-1.md) | Nov 7, 2026 |
| Linux | kernel-azure opensuse-leap 16.0 | 6.12.0-160000.40.1 | [OPENSUSE-SU-2026:22167-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22167-1.md) | Nov 7, 2026 |
| Linux | kernel-azure sles 16.0 | 6.12.0-160000.40.1 | [SUSE-SU-2026:24446-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24446-1.md) | Nov 7, 2026 |
| Linux | kernel-default opensuse-leap 16.0 | 6.12.0-160000.40.1 | [OPENSUSE-SU-2026:22167-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22167-1.md) | Nov 7, 2026 |
| Linux | kernel-default sles 16.0 | 6.12.0-160000.40.1 | [SUSE-SU-2026:24446-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24446-1.md) | Nov 7, 2026 |
| Linux | kernel-default-base opensuse-leap 16.0 | 6.12.0-160000.40.1.160000.2.29 | [OPENSUSE-SU-2026:22167-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22167-1.md) | Nov 7, 2026 |
| Linux | kernel-default-base sles 16.0 | 6.12.0-160000.40.1.160000.2.29 | [SUSE-SU-2026:24446-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24446-1.md) | Nov 7, 2026 |
| Linux | kernel-docs opensuse-leap 16.0 | 6.12.0-160000.40.1 | [OPENSUSE-SU-2026:22167-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22167-1.md) | Nov 7, 2026 |
| Linux | kernel-docs sles 16.0 | 6.12.0-160000.40.1 | [SUSE-SU-2026:24446-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24446-1.md) | Nov 7, 2026 |
| Linux | kernel-kvmsmall opensuse-leap 16.0 | 6.12.0-160000.40.1 | [OPENSUSE-SU-2026:22167-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22167-1.md) | Nov 7, 2026 |
| Linux | kernel-kvmsmall sles 16.0 | 6.12.0-160000.40.1 | [SUSE-SU-2026:24446-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24446-1.md) | Nov 7, 2026 |
| Linux | kernel-livepatch-6.12.113-138.209 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-3335](https://patchblox.com/security/data/fix/linux/alas2023-2026-3335.md) | Nov 7, 2026 |
| Linux | kernel-livepatch-6.18.54-121.166 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 |
| Linux | kernel-obs-build opensuse-leap 16.0 | 6.12.0-160000.40.1 | [OPENSUSE-SU-2026:22167-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22167-1.md) | Nov 7, 2026 |
| Linux | kernel-obs-qa opensuse-leap 16.0 | 6.12.0-160000.40.1 | [OPENSUSE-SU-2026:22167-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22167-1.md) | Nov 7, 2026 |
| Linux | kernel-obs-qa sles 16.0 | 6.12.0-160000.40.1 | [SUSE-SU-2026:24446-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24446-1.md) | Nov 7, 2026 |
| Linux | kernel-rt opensuse-leap 16.0 | 6.12.0-160000.40.1 | [OPENSUSE-SU-2026:22167-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22167-1.md) | Nov 7, 2026 |
| Linux | kernel-source opensuse-leap 16.0 | 6.12.0-160000.40.1 | [OPENSUSE-SU-2026:22167-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22167-1.md) | Nov 7, 2026 |
| Linux | kernel-source sles 16.0 | 6.12.0-160000.40.1 | [SUSE-SU-2026:24446-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24446-1.md) | Nov 7, 2026 |
| Linux | kernel-syms opensuse-leap 16.0 | 6.12.0-160000.40.1 | [OPENSUSE-SU-2026:22167-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22167-1.md) | Nov 7, 2026 |
| Linux | kernel-syms sles 16.0 | 6.12.0-160000.40.1 | [SUSE-SU-2026:24446-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24446-1.md) | Nov 7, 2026 |
| Linux | kernel-zfcpdump opensuse-leap 16.0 | 6.12.0-160000.40.1 | [OPENSUSE-SU-2026:22167-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22167-1.md) | Nov 7, 2026 |
| Linux | kernel-zfcpdump sles 16.0 | 6.12.0-160000.40.1 | [SUSE-SU-2026:24446-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24446-1.md) | Nov 7, 2026 |
| Linux | kernel6.12 amzn 2023 | 1:6.12.113-138.209.amzn2023 | [ALAS2023-2026-3335](https://patchblox.com/security/data/fix/linux/alas2023-2026-3335.md) | Nov 7, 2026 |
| Linux | kernel6.12-debuginfo amzn 2023 | 1:6.12.113-138.209.amzn2023 | [ALAS2023-2026-3335](https://patchblox.com/security/data/fix/linux/alas2023-2026-3335.md) | Nov 7, 2026 |
| Linux | kernel6.12-debuginfo-common-aarch64 amzn 2023 | 1:6.12.113-138.209.amzn2023 | [ALAS2023-2026-3335](https://patchblox.com/security/data/fix/linux/alas2023-2026-3335.md) | Nov 7, 2026 |
| Linux | kernel6.12-debuginfo-common-x86_64 amzn 2023 | 1:6.12.113-138.209.amzn2023 | [ALAS2023-2026-3335](https://patchblox.com/security/data/fix/linux/alas2023-2026-3335.md) | Nov 7, 2026 |
| Linux | kernel6.12-devel amzn 2023 | 1:6.12.113-138.209.amzn2023 | [ALAS2023-2026-3335](https://patchblox.com/security/data/fix/linux/alas2023-2026-3335.md) | Nov 7, 2026 |
| Linux | kernel6.12-headers amzn 2023 | 1:6.12.113-138.209.amzn2023 | [ALAS2023-2026-3335](https://patchblox.com/security/data/fix/linux/alas2023-2026-3335.md) | Nov 7, 2026 |
| Linux | kernel6.12-modules-extra amzn 2023 | 1:6.12.113-138.209.amzn2023 | [ALAS2023-2026-3335](https://patchblox.com/security/data/fix/linux/alas2023-2026-3335.md) | Nov 7, 2026 |
| Linux | kernel6.12-modules-extra-common amzn 2023 | 1:6.12.113-138.209.amzn2023 | [ALAS2023-2026-3335](https://patchblox.com/security/data/fix/linux/alas2023-2026-3335.md) | Nov 7, 2026 |
| Linux | kernel6.12-tools amzn 2023 | 1:6.12.113-138.209.amzn2023 | [ALAS2023-2026-3335](https://patchblox.com/security/data/fix/linux/alas2023-2026-3335.md) | Nov 7, 2026 |
| Linux | kernel6.12-tools-debuginfo amzn 2023 | 1:6.12.113-138.209.amzn2023 | [ALAS2023-2026-3335](https://patchblox.com/security/data/fix/linux/alas2023-2026-3335.md) | Nov 7, 2026 |
| Linux | kernel6.12-tools-devel amzn 2023 | 1:6.12.113-138.209.amzn2023 | [ALAS2023-2026-3335](https://patchblox.com/security/data/fix/linux/alas2023-2026-3335.md) | Nov 7, 2026 |
| Linux | kernel6.18 amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 |
| Linux | kernel6.18-debuginfo amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 |
| Linux | kernel6.18-debuginfo-common-aarch64 amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 |
| Linux | kernel6.18-debuginfo-common-x86_64 amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 |
| Linux | kernel6.18-devel amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 |
| Linux | kernel6.18-headers amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 |
| Linux | kernel6.18-modules-extra amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 |
| Linux | kernel6.18-modules-extra-common amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 |
| Linux | kernel6.18-tools amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 |
| Linux | kernel6.18-tools-debuginfo amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 |
| Linux | kernel6.18-tools-devel amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.113-1 | [DEBIAN-CVE-2026-97558](https://patchblox.com/security/data/fix/linux/debian-cve-2026-97558.md) | Oct 2, 2026 |
| Linux | linux Debian 14 | 7.2.7-1 | [DEBIAN-CVE-2026-97558](https://patchblox.com/security/data/fix/linux/debian-cve-2026-97558.md) | Oct 2, 2026 |
| Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.113-1~deb12u1 | [DEBIAN-CVE-2026-97558](https://patchblox.com/security/data/fix/linux/debian-cve-2026-97558.md) | Oct 2, 2026 |
| Linux | microvm-kernel6.18 amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 |
| Linux | perf6.12 amzn 2023 | 1:6.12.113-138.209.amzn2023 | [ALAS2023-2026-3335](https://patchblox.com/security/data/fix/linux/alas2023-2026-3335.md) | Nov 7, 2026 |
| Linux | perf6.12-debuginfo amzn 2023 | 1:6.12.113-138.209.amzn2023 | [ALAS2023-2026-3335](https://patchblox.com/security/data/fix/linux/alas2023-2026-3335.md) | Nov 7, 2026 |
| Linux | perf6.18 amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 |
| Linux | perf6.18-debuginfo amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 |
| Linux | python3-perf6.12 amzn 2023 | 1:6.12.113-138.209.amzn2023 | [ALAS2023-2026-3335](https://patchblox.com/security/data/fix/linux/alas2023-2026-3335.md) | Nov 7, 2026 |
| Linux | python3-perf6.12-debuginfo amzn 2023 | 1:6.12.113-138.209.amzn2023 | [ALAS2023-2026-3335](https://patchblox.com/security/data/fix/linux/alas2023-2026-3335.md) | Nov 7, 2026 |
| Linux | python3-perf6.18 amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 |
| Linux | python3-perf6.18-debuginfo amzn 2023 | 1:6.18.54-121.166.amzn2023 | [ALAS2023-2026-3192](https://patchblox.com/security/data/fix/linux/alas2023-2026-3192.md) | Nov 7, 2026 |

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