Upstream information
Description
In the Linux kernel, the following vulnerability has been resolved:selinux: preserve user SID across nested backing files
SELinux saves the user file SID in a backing-file security blob so it
remains available after mmap() replaces vma->vm_file with a backing file.
For nested backing files (overlayfs over overlayfs, or FUSE passthrough
backed by overlayfs), user_file may itself be a backing file. Its
fsec->sid is the SID of the mounter that opened it, rather than the user
that opened the top-level file. mprotect() then checks fd { use } against
the mounter SID. This can incorrectly deny access without a domain
transition, or check the wrong target SID after one.
Copy the saved user SID when user_file is a backing file. Keep using the
regular file SID for the first backing layer.
With two nested overlayfs mounts and SELinux enforcing,
mprotect(PROT_READ) returns EACCES with an fd { use } denial against the
mounter SID. With this change, mprotect() succeeds.
Tested on arm64 QEMU with a small BusyBox initramfs and a purpose-built
SELinux policy. The original test was also repeated with Fedora Cloud
Base 44 userspace and gave the same result.
SUSE information
Overall state of this security issue: Resolved
This issue is currently rated as having low severity.
| CVSS detail | SUSE |
|---|---|
| Base Score | 2.5 |
| Vector | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N |
| Attack Vector | Local |
| Attack Complexity | High |
| Privileges Required | Low |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality Impact | Low |
| Integrity Impact | None |
| Availability Impact | None |
| 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: 1284558 [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Please note that this evaluation state might be work in progress, incomplete or outdated.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 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 |
| Products at an unknown state of their lifecycle. | ||
| SUSE Linux Enterprise Server for NVIDIA 16.1 | kernel-source | Not affected |
SUSE Timeline for this CVE
CVE page created: Thu Oct 8 12:09:34 2026CVE page last modified: Thu Oct 8 18:02:21 2026