Upstream information

CVE-2026-63827 at MITRE

Description

In the Linux kernel, the following vulnerability has been resolved:

apparmor: fix use-after-free in rawdata dedup loop

aa_replace_profiles() walks ns->rawdata_list to dedup the incoming
policy blob against entries already attached to existing profiles.
Per the kernel-doc on struct aa_loaddata, list membership does not
hold a reference: profiles hold pcount, and when the last pcount
drops, do_ploaddata_rmfs() is queued on a workqueue that takes
ns->lock and removes the entry. Between dropping the last pcount
and the workqueue running, an entry remains on the list with
pcount == 0.

aa_get_profile_loaddata() is an unconditional kref_get() on
pcount, so when the dedup loop hits such an entry, refcount
hardening reports

refcount_t: addition on 0; use-after-free.

inside aa_replace_profiles(), and the poisoned counter then
trips "saturated" and "underflow" warnings on the subsequent
uses of the same loaddata.

Before commit a0b7091c4de4 ("apparmor: fix race on rawdata
dereference") the dedup path used a get_unless_zero-style helper
on a single counter, so the existing "if (tmp)" guard was
meaningful. The split-refcount refactor introduced
aa_get_profile_loaddata(), which has plain kref_get() semantics,
and the guard quietly became a no-op.

Introduce aa_get_profile_loaddata_not0(), matching the existing
_not0 convention used by aa_get_profile_not0(), and use it for
the rawdata_list dedup lookup so dying entries are skipped.

Reproduced on x86_64 with v7.1-rc5 in QEMU+KVM running Ubuntu
24.04 + stress-ng 0.17.06:

stress-ng --apparmor 1 --klog-check --timeout 60s

Without this patch the three refcount_t warnings fire within a
few seconds. With it the same 60 s run is clean. Coverage is a
smoke-test only; a longer soak with CONFIG_KASAN, CONFIG_KCSAN
and CONFIG_PROVE_LOCKING would be welcome from anyone with the
cycles.

SUSE information

Overall state of this security issue: Pending

This issue is currently rated as having important severity.

CVSS v3 Scores
CVSS detail CNA (NVD) Linux Kernel CNA SUSE
Base Score 7.8 7.8 7.8
Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack Vector Local Local Local
Attack Complexity Low Low Low
Privileges Required Low Low Low
User Interaction None None None
Scope Unchanged Unchanged Unchanged
Confidentiality Impact High High High
Integrity Impact High High High
Availability Impact High High High
CVSSv3 Version 3.1 3.1 3.1
CVSS v4 Scores
CVSS detail SUSE
Base Score 8.5
Vector CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Attack Vector Local
Attack Complexity Low
Attack Requirements None
Privileges Required Low
User Interaction None
Vulnerable System Confidentiality Impact High
Vulnerable System Integrity Impact High
Vulnerable System Availability Impact High
Subsequent System Confidentiality Impact None
Subsequent System Integrity Impact None
Subsequent System Availability Impact None
CVSSv4 Version 4.0

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 entries: 1272179 [NEW], 1272203 [NEW]

No SUSE Security Announcements cross referenced.

List of released packages

Product(s) Fixed package version(s) References
openSUSE Tumbleweed
  • kernel-devel >= 7.1.4-1.1
  • kernel-macros >= 7.1.4-1.1
  • kernel-source >= 7.1.4-1.1
  • kernel-source-vanilla >= 7.1.4-1.1
Patchnames:
openSUSE-Tumbleweed-2026-11339


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 Affected
SUSE Linux Enterprise Desktop 15 SP7 kernel-source Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 kernel-default Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 kernel-source 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 Affected
SUSE Linux Enterprise High Availability Extension 16.1 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP7 kernel-default Affected
SUSE Linux Enterprise High Performance Computing 15 SP7 kernel-source Affected
SUSE Linux Enterprise Live Patching 15 SP7 kernel-default Affected
SUSE Linux Enterprise Live Patching 15 SP7 kernel-source Affected
SUSE Linux Enterprise Micro 5.3 kernel-default Affected
SUSE Linux Enterprise Micro 5.3 kernel-rt Affected
SUSE Linux Enterprise Micro 5.3 kernel-source Affected
SUSE Linux Enterprise Micro 5.3 kernel-source-rt Affected
SUSE Linux Enterprise Micro 5.4 kernel-default Affected
SUSE Linux Enterprise Micro 5.4 kernel-rt Affected
SUSE Linux Enterprise Micro 5.4 kernel-source Affected
SUSE Linux Enterprise Micro 5.4 kernel-source-rt Affected
SUSE Linux Enterprise Micro 5.5 kernel-default Affected
SUSE Linux Enterprise Micro 5.5 kernel-source Affected
SUSE Linux Enterprise Micro 5.5 kernel-source-rt Affected
SUSE Linux Enterprise Module for Basesystem 15 SP7 kernel-default Affected
SUSE Linux Enterprise Module for Basesystem 15 SP7 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP7 kernel-default Affected
SUSE Linux Enterprise Module for Development Tools 15 SP7 kernel-source Affected
SUSE Linux Enterprise Module for Legacy 15 SP7 kernel-default Affected
SUSE Linux Enterprise Module for Legacy 15 SP7 kernel-source Affected
SUSE Linux Enterprise Module for Public Cloud 15 SP7 kernel-default Affected
SUSE Linux Enterprise Module for Public Cloud 15 SP7 kernel-source Affected
SUSE Linux Enterprise Real Time 15 SP7 kernel-source-rt Affected
SUSE Linux Enterprise Server 15 SP7 kernel-default Affected
SUSE Linux Enterprise Server 15 SP7 kernel-source 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 Affected
SUSE Linux Enterprise Server 16.1 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP7 kernel-default Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP7 kernel-source 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 Affected
SUSE Linux Enterprise Server for SAP applications 16.1 kernel-source Affected
SUSE Linux Enterprise Workstation Extension 15 SP7 kernel-default Affected
SUSE Linux Enterprise Workstation Extension 15 SP7 kernel-source Affected
SUSE Linux Micro 6.0 kernel-default Affected
SUSE Linux Micro 6.0 kernel-source Affected
SUSE Linux Micro 6.0 kernel-source-rt Affected
SUSE Linux Micro 6.1 kernel-default Affected
SUSE Linux Micro 6.1 kernel-source Affected
SUSE Linux Micro 6.1 kernel-source-rt 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 Affected
SUSE Linux Micro Extras 6.0 kernel-source Affected
SUSE Linux Micro Extras 6.0 kernel-source-rt Affected
SUSE Real Time Module 15 SP7 kernel-source-rt 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-default Not affected
SUSE Linux Enterprise High Performance Computing 12 SP5 kernel-source Not affected
SUSE Linux Enterprise High Performance Computing 15 SP4 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-default Affected
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP5 kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS kernel-default Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS kernel-source Affected
SUSE Linux Enterprise Live Patching 12 SP5 kernel-default Not affected
SUSE Linux Enterprise Live Patching 12 SP5 kernel-source Not affected
SUSE Linux Enterprise Live Patching 15 SP4 kernel-default Affected
SUSE Linux Enterprise Live Patching 15 SP4 kernel-source Affected
SUSE Linux Enterprise Live Patching 15 SP5 kernel-default Affected
SUSE Linux Enterprise Live Patching 15 SP5 kernel-source Affected
SUSE Linux Enterprise Module for Basesystem 15 SP4 kernel-source Affected
SUSE Linux Enterprise Module for Basesystem 15 SP5 kernel-source Affected
SUSE Linux Enterprise Module for Basesystem 15 SP6 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP4 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP5 kernel-source Affected
SUSE Linux Enterprise Module for Development Tools 15 SP6 kernel-source 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 12 SP5-LTSS Extended Security kernel-default Not affected
SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security kernel-source Not affected
SUSE Linux Enterprise Server 15 SP4 kernel-source Affected
SUSE Linux Enterprise Server 15 SP4-LTSS kernel-default Affected
SUSE Linux Enterprise Server 15 SP4-LTSS kernel-source Affected
SUSE Linux Enterprise Server 15 SP5 kernel-source Affected
SUSE Linux Enterprise Server 15 SP5-LTSS kernel-default Affected
SUSE Linux Enterprise Server 15 SP5-LTSS kernel-source Affected
SUSE Linux Enterprise Server 15 SP6 kernel-source Affected
SUSE Linux Enterprise Server 15 SP6-LTSS kernel-default Affected
SUSE Linux Enterprise Server 15 SP6-LTSS kernel-source Affected
SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 kernel-source Not affected
SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-default Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP6 kernel-source Affected
SUSE Manager Proxy 4.3 kernel-source Affected
SUSE Manager Proxy LTS 4.3 kernel-source Affected
SUSE Manager Retail Branch Server 4.3 kernel-source Affected
SUSE Manager Retail Branch Server LTS 4.3 kernel-source Affected
SUSE Manager Server 4.3 kernel-source Affected
SUSE Manager Server LTS 4.3 kernel-source 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 Affected
SUSE Linux Enterprise Desktop 15 SP5 kernel-source Affected
SUSE Linux Enterprise Desktop 15 SP6 kernel-source 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-ESPOS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS kernel-source Affected
SUSE Linux Enterprise High Performance Computing 15 SP6 kernel-source 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 Affected
SUSE Linux Enterprise Real Time 15 SP4 kernel-source-rt Affected
SUSE Linux Enterprise Real Time 15 SP5 kernel-source-rt 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 Linux Enterprise Server for SAP Applications 15 SP4 kernel-default Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-source Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-default Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-source 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 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 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 Real Time Module 15 SP4 kernel-source-rt Affected
SUSE Real Time Module 15 SP5 kernel-source-rt Affected
openSUSE Leap 15.3 kernel-source Not affected
openSUSE Leap 15.4 kernel-source Affected
openSUSE Leap 15.4 kernel-source-rt Affected
openSUSE Leap 15.5 kernel-source Affected
openSUSE Leap 15.5 kernel-source-rt Affected
openSUSE Leap 15.6 kernel-source Affected


SUSE Timeline for this CVE

CVE page created: Sun Jul 19 17:31:17 2026
CVE page last modified: Mon Jul 27 19:40:32 2026