CVE-2026-90156 json
ksmbd: safely discard unregistered deferred locks
published 2026-09-17 52 d ago modified 2026-10-30 9 d ago also EUVD-2026-81749
- cvss
- —
- not scored
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 11%
- public exploits
- 0
- none known
Summary
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: safely discard unregistered deferred locks
When vfs_lock_file() defers a lock, smb2_lock() puts its ksmbd_lock on rollback_list before allocating and registering the asynchronous work. If either operation fails, rollback assumes that smb_lock->conn is initialized and dereferences NULL. The deferred file_lock also remains linked into the VFS blocked-lock state while it is freed.
Keep the lock off rollback_list until async setup succeeds. On setup failures, explicitly unblock and wake the deferred lock before freeing it and its ksmbd wrapper.
Patch / fix
- Linux Linux 6.1.191, 6.6.160, 6.12.114, 6.18.57, 7.2.6, 7.3
- linux Debian 13 6.12.115-2
- linux Debian 14 7.2.6-1
debian advisories DEBIAN-CVE-2026-90156
- linux Ubuntu 26.04 LTS 7.0.0-42.42
- linux-aws Ubuntu 26.04 LTS 7.0.0-1016.17
- linux-gcp Ubuntu 26.04 LTS 7.0.0-1016.18
- linux-ibm Ubuntu 26.04 LTS 7.0.0-1017.17
- linux-riscv Ubuntu 26.04 LTS 7.0.0-42.42.1
- linux-oracle Ubuntu 26.04 LTS 7.0.0-1015.16
- linux-hwe-7.0 Ubuntu 24.04 LTS 7.0.0-42.42~24.04.1
- linux-oem-7.0 Ubuntu 26.04 LTS 7.0.0-1017.17
ubuntu advisories UBUNTU-CVE-2026-90156
Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
- kernel-source openSUSE Tumbleweed 7.2.7-1.1
opensuse advisories openSUSE-SU-2026:11880-1
- kernel Azure Linux 3.0 6.6.161.1-1
azure linux advisories AZL-102651
Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT
- git.kernel.org/stable/c/aaa51ac0d934cb4e2ab96e150fccc934e822009b commit
- git.kernel.org/stable/c/ecdcfa15b3d799476c685cecd433ebefc93015c8 commit
- git.kernel.org/stable/c/77413400f083a959724de6f36348c9677ef9873a commit
- git.kernel.org/stable/c/52b91bc5253bb83665f3ea70565d0b2487dae643 commit
- git.kernel.org/stable/c/d09af9a35ff7b77a950b507133d9092aadbfeff4 commit
- git.kernel.org/stable/c/054bcca4cd9f00719b01f7108b51a2168fb94f15 commit
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2026-90156 updated cvss 5.5
kernel: ksmbd: safely discard unregistered deferred locks
-
Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9not affected: vulnerable code not present
+1 more productsfewer
Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
Exploit prediction
0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-08).
Affected products
- Linux Linux
Classification
- Technology feeds
References
- git.kernel.org /stable/c/aaa51ac0d934cb4e2ab96e150fccc934e822009b
- git.kernel.org /stable/c/ecdcfa15b3d799476c685cecd433ebefc93015c8
- git.kernel.org /stable/c/77413400f083a959724de6f36348c9677ef9873a
- git.kernel.org /stable/c/52b91bc5253bb83665f3ea70565d0b2487dae643
- git.kernel.org /stable/c/d09af9a35ff7b77a950b507133d9092aadbfeff4
- git.kernel.org /stable/c/054bcca4cd9f00719b01f7108b51a2168fb94f15
Sources
- CVE List CVE-2026-90156
- NVD CVE-2026-90156
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.