Upstream information
Description
In the Linux kernel, the following vulnerability has been resolved:unshare: don't drop active namespace references that were never taken
Active references on the namespaces of an nsproxy are taken when the
nsproxy is installed into a task in switch_task_namespaces() and
copy_namespaces() and dropped again by put_nsproxy() through
deactivate_nsproxy().
But ksys_unshare() calls put_nsproxy() on an nsproxy that was never
installed when set_cred_ucounts() fails. The new namespaces of that
nsproxy go from zero to minus one and the namespaces shared with the
caller lose a reference that belongs to the nsproxy the caller keeps
using:
WARNING: kernel/nscommon.c:171 at __ns_ref_active_put+0x1cd/0x230
nsproxy_ns_active_put
deactivate_nsproxy
ksys_unshare
Afterwards the namespaces the caller lives in aren't listed by listns()
anymore. set_cred_ucounts() only fails when alloc_ucounts() can't
allocate and it only allocates when the real uid of the caller differs
from its effective uid.
Commit cefd55bd2159 ("nsproxy: fix free_nsproxy() and simplify
create_new_namespaces()") separated the two cases on purpose.
nsproxy_free() frees an nsproxy that was prepared but never installed
and that's what a failed setns() uses in put_nsset(). Export it and use
it for a failed unshare() as well.
SUSE information
Overall state of this security issue: Resolved
This issue is currently rated as having moderate severity.
| CVSS detail | SUSE |
|---|---|
| Base Score | 5.5 |
| Vector | 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 Impact | None |
| Integrity Impact | None |
| Availability Impact | High |
| CVSSv3 Version | 3.1 |
Note from the SUSE Security Team on the kernel-default package
SUSE will no longer fix all CVEs in the Linux Kernel anymore, but declare some bug classes as won't fix. Please refer to TID 21496 for more details. SUSE Bugzilla entry: 1287731 [NEW] No SUSE Security Announcements cross referenced.Status of this issue by product and package
Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.
| Product(s) | Source package | State |
|---|---|---|
| Products under general support and receiving all security fixes. | ||
| SUSE Linux Enterprise Desktop 15 SP7 | kernel-default | Not affected |
| SUSE Linux Enterprise Desktop 15 SP7 | kernel-source | Not affected |
| SUSE Linux Enterprise High Availability Extension 15 SP7 | kernel-default | Not affected |
| SUSE Linux Enterprise High Availability Extension 15 SP7 | kernel-source | Not affected |
| SUSE Linux Enterprise High Availability Extension 16.0 | kernel-default | Not affected |
| SUSE Linux Enterprise High Availability Extension 16.0 | kernel-source | Not affected |
| SUSE Linux Enterprise High Availability Extension 16.1 | kernel-default | Not affected |
| SUSE Linux Enterprise High Availability Extension 16.1 | kernel-source | Not affected |
| SUSE Linux Enterprise Micro 5.3 | kernel-default | Not affected |
| SUSE Linux Enterprise Micro 5.3 | kernel-rt | Not affected |
| SUSE Linux Enterprise Micro 5.3 | kernel-source | Not affected |
| SUSE Linux Enterprise Micro 5.3 | kernel-source-rt | Not affected |
| SUSE Linux Enterprise Micro 5.4 | kernel-default | Not affected |
| SUSE Linux Enterprise Micro 5.4 | kernel-rt | Not affected |
| SUSE Linux Enterprise Micro 5.4 | kernel-source | Not affected |
| SUSE Linux Enterprise Micro 5.4 | kernel-source-rt | Not affected |
| SUSE Linux Enterprise Micro 5.5 | kernel-default | Not affected |
| SUSE Linux Enterprise Micro 5.5 | kernel-source | Not affected |
| SUSE Linux Enterprise Micro 5.5 | kernel-source-rt | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | kernel-default | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP7 | kernel-default | Not affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP7 | kernel-source | Not affected |
| SUSE Linux Enterprise Real Time 15 SP7 | kernel-source-rt | Not affected |
| SUSE Linux Enterprise Server 15 SP7 | kernel-default | Not affected |
| SUSE Linux Enterprise Server 15 SP7 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 16.0 | kernel-default | Not affected |
| SUSE Linux Enterprise Server 16.0 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 16.1 | kernel-default | Not affected |
| SUSE Linux Enterprise Server 16.1 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for NVIDIA 16.1 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | kernel-default | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP applications 16.0 | kernel-default | Not affected |
| SUSE Linux Enterprise Server for SAP applications 16.0 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP applications 16.1 | kernel-default | Not affected |
| SUSE Linux Enterprise Server for SAP applications 16.1 | kernel-source | Not affected |
| SUSE Linux Micro 6.0 | kernel-default | Not affected |
| SUSE Linux Micro 6.0 | kernel-source | Not affected |
| SUSE Linux Micro 6.0 | kernel-source-rt | Not affected |
| SUSE Linux Micro 6.1 | kernel-default | Not affected |
| SUSE Linux Micro 6.1 | kernel-source | Not affected |
| SUSE Linux Micro 6.1 | kernel-source-rt | Not affected |
| SUSE Linux Micro 6.2 | kernel-default | Not affected |
| SUSE Linux Micro 6.2 | kernel-source | Not affected |
| SUSE Linux Micro Extras 6.0 | kernel-default | Not affected |
| SUSE Linux Micro Extras 6.0 | kernel-source | Not affected |
| SUSE Linux Micro Extras 6.0 | kernel-source-rt | Not affected |
| SUSE Linux Micro Extras 6.1 | kernel-default | Not affected |
| SUSE Linux Micro Extras 6.1 | kernel-source | Not affected |
| SUSE Real Time Module 15 SP7 | kernel-source-rt | Not affected |
| openSUSE Leap 16.0 | kernel-source | Not affected |
| Products under Long Term Service Pack support and receiving important and critical security fixes. | ||
| SUSE Linux Enterprise High Performance Computing 12 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP6 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP6 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE | kernel-default | Not affected |
| SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE | kernel-source | Not affected |
| SUSE Linux Enterprise Server 12 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP6 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP6-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 15 SP6-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | kernel-default | Not affected |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | kernel-default | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | kernel-default | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | kernel-default | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | kernel-source | Not affected |
| Products past their end of life and not receiving proactive updates anymore. | ||
| SUSE CaaS Platform 4.0 | kernel-source | Not affected |
| SUSE Enterprise Storage 6 | kernel-source | Not affected |
| SUSE Enterprise Storage 7 | kernel-source | Not affected |
| SUSE Enterprise Storage 7.1 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 11 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 15 SP3 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 15 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 15 SP5 | kernel-source | Not affected |
| SUSE Linux Enterprise Desktop 15 SP6 | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3 | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | kernel-source | Not affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | kernel-source | Not affected |
| SUSE Linux Enterprise Micro 5.0 | kernel-default | Not affected |
| SUSE Linux Enterprise Micro 5.1 | kernel-default | Not affected |
| SUSE Linux Enterprise Micro 5.2 | kernel-default | Not affected |
| SUSE Linux Enterprise Micro 5.2 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP3 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP3 | kernel-source | Not affected |
| SUSE Linux Enterprise Real Time 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Real Time 15 SP3 | kernel-source | Not affected |
| SUSE Linux Enterprise Real Time 15 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Real Time 15 SP4 | kernel-source-rt | Not affected |
| SUSE Linux Enterprise Real Time 15 SP5 | kernel-source-rt | Not affected |
| SUSE Linux Enterprise Server 11 SP4 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 11 SP4-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP1-BCL | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP1-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 15 SP1-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP2-BCL | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP3 | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP3-BCL | kernel-source | Not affected |
| SUSE Linux Enterprise Server 15 SP3-LTSS | kernel-default | Not affected |
| SUSE Linux Enterprise Server 15 SP3-LTSS | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP1 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP2 | kernel-source | Not affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | kernel-source | Not affected |
| SUSE Manager Proxy 4.0 | kernel-source | Not affected |
| SUSE Manager Proxy 4.1 | kernel-source | Not affected |
| SUSE Manager Proxy 4.2 | kernel-source | Not affected |
| SUSE Manager Proxy 4.3 | kernel-source | Not affected |
| SUSE Manager Proxy LTS 4.3 | kernel-source | Not affected |
| SUSE Manager Retail Branch Server 4.0 | kernel-source | Not affected |
| SUSE Manager Retail Branch Server 4.1 | kernel-source | Not affected |
| SUSE Manager Retail Branch Server 4.2 | kernel-source | Not affected |
| SUSE Manager Retail Branch Server 4.3 | kernel-source | Not affected |
| SUSE Manager Retail Branch Server LTS 4.3 | kernel-source | Not affected |
| SUSE Manager Server 4.0 | kernel-source | Not affected |
| SUSE Manager Server 4.1 | kernel-source | Not affected |
| SUSE Manager Server 4.2 | kernel-source | Not affected |
| SUSE Manager Server 4.3 | kernel-source | Not affected |
| SUSE Manager Server LTS 4.3 | kernel-source | Not affected |
| SUSE Real Time Module 15 SP4 | kernel-source-rt | Not affected |
| SUSE Real Time Module 15 SP5 | kernel-source-rt | Not affected |
| openSUSE Leap 15.3 | kernel-source | Not affected |
| openSUSE Leap 15.4 | kernel-source | Not affected |
| openSUSE Leap 15.4 | kernel-source-rt | Not affected |
| openSUSE Leap 15.5 | kernel-source | Not affected |
| openSUSE Leap 15.5 | kernel-source-rt | Not affected |
| openSUSE Leap 15.6 | kernel-source | Not affected |
SUSE Timeline for this CVE
CVE page created: Mon Oct 26 17:54:59 2026CVE page last modified: Tue Oct 27 17:48:52 2026