Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Local access with low privileges required to reach fprobe tracing interfaces; UAF enables full kernel memory corruption yielding C:H/I:H/A:H.
AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
Primary rating from NVD.
CVSS VectorNVD
Lifecycle Timeline
6DescriptionNVD
In the Linux kernel, the following vulnerability has been resolved:
fprobe: Fix unregister_fprobe() to wait for RCU grace period
Commit 4346ba1604093 ("fprobe: Rewrite fprobe on function-graph tracer") changed fprobe to register struct fprobe to an rcu-hlist, but it forgot to wait for RCU GP. Thus there can be use-after-free if the fprobe is released right after unregistering. This can be happened on fprobe event and sample module code.
To fix this issue, add synchronize_rcu() in unregister_fprobe().
Note that BPF is OK because fprobe is used as a part of bpf_kprobe_multi_link. This unregisters its fprobe in bpf_kprobe_multi_link_release() and it is deallocated via bpf_kprobe_multi_link_dealloc(), which is invoked from bpf_link_defer_dealloc_rcu_gp() RCU callback.
For BPF, this also introduced unregister_fprobe_async() which does NOT wait for RCU grace priod.
AnalysisAI
Use-after-free in the Linux kernel's fprobe subsystem exposes kernel memory to corruption when a fprobe is released immediately after unregistration without waiting for an RCU grace period. The flaw was introduced by commit 4346ba1604093, which rewrote fprobe on the function-graph tracer and placed struct fprobe on an RCU-protected hlist but omitted the required synchronize_rcu() call in unregister_fprobe(), leaving a window where in-flight RCU readers may dereference freed memory. BPF users of fprobe are explicitly unaffected because BPF defers deallocation through the bpf_link_defer_dealloc_rcu_gp() RCU callback; affected paths are fprobe events and sample module code.
Technical ContextAI
The fprobe subsystem provides kernel function entry and exit probing, layered on top of the function-graph tracer. Commit 4346ba1604093 refactored fprobe registration to use an RCU-protected hlist (a linked list safe for lockless concurrent readers via the Read-Copy-Update mechanism). RCU semantics require that after removing an element from such a list, the caller must wait for a grace period - during which all pre-existing RCU read-side critical sections complete - before freeing the element. The missing synchronize_rcu() in unregister_fprobe() violates this contract: if a caller frees the fprobe struct immediately after unregistering, any concurrent RCU reader that already holds a reference to it will dereference freed memory (CWE-416: Use After Free). The CPE cpe:2.3:a:linux:linux:*:*:*:*:*:*:*:* covers the Linux kernel codebase broadly; affected versions span from commit 4346ba1604093 through the stable-tree fix commits.
RemediationAI
Upgrade to a patched Linux kernel release: version 7.1 or later on mainline, 7.0.11 or later on the 7.0.x stable branch (patch commit 56b4cfcf1518245493c60fd39c56978f508f1816 at https://git.kernel.org/stable/c/56b4cfcf1518245493c60fd39c56978f508f1816), or 6.18.34 or later on the 6.18.x stable branch (patch commit a4f6a9005ed6cfd360ef2520430927f05f92ffb0 at https://git.kernel.org/stable/c/a4f6a9005ed6cfd360ef2520430927f05f92ffb0). Ubuntu users should apply the packages referenced in USN-8593-1 at https://ubuntu.com/security/notices/USN-8593-1. As a compensating control on systems that cannot be immediately patched, restrict access to the kernel tracing and fprobe event interfaces (typically under /sys/kernel/debug/tracing/) to root only using DAC permissions or Linux Security Module policies such as SELinux or AppArmor; this prevents low-privileged local users from triggering the vulnerable unregister path. Note that this workaround does not protect against root-level exploitation and may break legitimate tracing tooling.
Same weakness CWE-416 – Use After Free
View allSame technique Use After Free
View allVendor StatusVendor
SUSE
Severity: Moderate| Product | Status |
|---|---|
| SUSE Linux Enterprise Desktop 15 SP7 | Not-Affected |
| SUSE Linux Enterprise Desktop 15 SP7 | Not-Affected |
| SUSE Linux Enterprise High Availability Extension 15 SP7 | Not-Affected |
| SUSE Linux Enterprise High Availability Extension 15 SP7 | Not-Affected |
| SUSE Linux Enterprise High Availability Extension 16.0 | Not-Affected |
| SUSE Linux Enterprise High Availability Extension 16.0 | Not-Affected |
| SUSE Linux Enterprise High Availability Extension 16.1 | Not-Affected |
| SUSE Linux Enterprise High Availability Extension 16.1 | Not-Affected |
| SUSE Linux Enterprise Live Patching 15 SP7 | Not-Affected |
| SUSE Linux Enterprise Live Patching 15 SP7 | Not-Affected |
| SUSE Linux Enterprise Micro 5.3 | Not-Affected |
| SUSE Linux Enterprise Micro 5.3 | Not-Affected |
| SUSE Linux Enterprise Micro 5.3 | Not-Affected |
| SUSE Linux Enterprise Micro 5.3 | Not-Affected |
| SUSE Linux Enterprise Micro 5.4 | Not-Affected |
| SUSE Linux Enterprise Micro 5.4 | Not-Affected |
| SUSE Linux Enterprise Micro 5.4 | Not-Affected |
| SUSE Linux Enterprise Micro 5.4 | Not-Affected |
| SUSE Linux Enterprise Micro 5.5 | Not-Affected |
| SUSE Linux Enterprise Micro 5.5 | Not-Affected |
| SUSE Linux Enterprise Micro 5.5 | Not-Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | Not-Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | Not-Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP7 | Not-Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP7 | Not-Affected |
| SUSE Linux Enterprise Module for Legacy 15 SP7 | Not-Affected |
| SUSE Linux Enterprise Module for Legacy 15 SP7 | Not-Affected |
| SUSE Linux Enterprise Module for Public Cloud 15 SP7 | Not-Affected |
| SUSE Linux Enterprise Module for Public Cloud 15 SP7 | Not-Affected |
| SUSE Linux Enterprise Real Time 15 SP7 | Not-Affected |
| SUSE Linux Enterprise Server 15 SP7 | Not-Affected |
| SUSE Linux Enterprise Server 15 SP7 | Not-Affected |
| SUSE Linux Enterprise Server 16.0 | Not-Affected |
| SUSE Linux Enterprise Server 16.0 | Not-Affected |
| SUSE Linux Enterprise Server 16.1 | Not-Affected |
| SUSE Linux Enterprise Server 16.1 | Not-Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | Not-Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | Not-Affected |
| SUSE Linux Enterprise Server for SAP applications 16.0 | Not-Affected |
| SUSE Linux Enterprise Server for SAP applications 16.0 | Not-Affected |
| SUSE Linux Enterprise Server for SAP applications 16.1 | Not-Affected |
| SUSE Linux Enterprise Server for SAP applications 16.1 | Not-Affected |
| SUSE Linux Enterprise Workstation Extension 15 SP7 | Not-Affected |
| SUSE Linux Enterprise Workstation Extension 15 SP7 | Not-Affected |
| SUSE Linux Micro 6.0 | Not-Affected |
| SUSE Linux Micro 6.0 | Not-Affected |
| SUSE Linux Micro 6.0 | Not-Affected |
| SUSE Linux Micro 6.1 | Not-Affected |
| SUSE Linux Micro 6.1 | Not-Affected |
| SUSE Linux Micro 6.1 | Not-Affected |
| SUSE Linux Micro 6.2 | Not-Affected |
| SUSE Linux Micro 6.2 | Not-Affected |
| SUSE Linux Micro Extras 6.0 | Not-Affected |
| SUSE Linux Micro Extras 6.0 | Not-Affected |
| SUSE Linux Micro Extras 6.0 | Not-Affected |
| SUSE Real Time Module 15 SP7 | Not-Affected |
| openSUSE Leap 16.0 | Not-Affected |
| SUSE Linux Enterprise High Performance Computing 12 SP5 | Not-Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | Not-Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | Not-Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | Not-Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | Not-Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | Not-Affected |
| SUSE Linux Enterprise Live Patching 12 SP5 | Not-Affected |
| SUSE Linux Enterprise Live Patching 12 SP5 | Not-Affected |
| SUSE Linux Enterprise Live Patching 15 SP4 | Not-Affected |
| SUSE Linux Enterprise Live Patching 15 SP4 | Not-Affected |
| SUSE Linux Enterprise Live Patching 15 SP5 | Not-Affected |
| SUSE Linux Enterprise Live Patching 15 SP5 | Not-Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP4 | Not-Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP5 | Not-Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP6 | Not-Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP4 | Not-Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP5 | Not-Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP6 | Not-Affected |
| SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE | Not-Affected |
| SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE | Not-Affected |
| SUSE Linux Enterprise Server 12 SP5 | Not-Affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS | Not-Affected |
| SUSE Linux Enterprise Server 12 SP5-LTSS | Not-Affected |
| SUSE Linux Enterprise Server 15 SP4 | Not-Affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | Not-Affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | Not-Affected |
| SUSE Linux Enterprise Server 15 SP5 | Not-Affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | Not-Affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | Not-Affected |
| SUSE Linux Enterprise Server 15 SP6 | Not-Affected |
| SUSE Linux Enterprise Server 15 SP6-LTSS | Not-Affected |
| SUSE Linux Enterprise Server 15 SP6-LTSS | Not-Affected |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | Not-Affected |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | Not-Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | Not-Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | Not-Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | Not-Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | Not-Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | Not-Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | Not-Affected |
| SUSE CaaS Platform 4.0 | Not-Affected |
| SUSE Enterprise Storage 6 | Not-Affected |
| SUSE Enterprise Storage 7 | Not-Affected |
| SUSE Enterprise Storage 7.1 | Not-Affected |
| SUSE Linux Enterprise Desktop 11 SP4 | Not-Affected |
| SUSE Linux Enterprise Desktop 15 SP1 | Not-Affected |
| SUSE Linux Enterprise Desktop 15 SP2 | Not-Affected |
| SUSE Linux Enterprise Desktop 15 SP3 | Not-Affected |
| SUSE Linux Enterprise Desktop 15 SP4 | Not-Affected |
| SUSE Linux Enterprise Desktop 15 SP5 | Not-Affected |
| SUSE Linux Enterprise Desktop 15 SP6 | Not-Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1 | Not-Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS | Not-Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS | Not-Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2 | Not-Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS | Not-Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS | Not-Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3 | Not-Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS | Not-Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | Not-Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4 | Not-Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | Not-Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | Not-Affected |
| SUSE Linux Enterprise Micro 5.0 | Not-Affected |
| SUSE Linux Enterprise Micro 5.1 | Not-Affected |
| SUSE Linux Enterprise Micro 5.2 | Not-Affected |
| SUSE Linux Enterprise Micro 5.2 | Not-Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP1 | Not-Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP2 | Not-Affected |
| SUSE Linux Enterprise Module for Basesystem 15 SP3 | Not-Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP1 | Not-Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP2 | Not-Affected |
| SUSE Linux Enterprise Module for Development Tools 15 SP3 | Not-Affected |
| SUSE Linux Enterprise Real Time 15 SP2 | Not-Affected |
| SUSE Linux Enterprise Real Time 15 SP3 | Not-Affected |
| SUSE Linux Enterprise Real Time 15 SP4 | Not-Affected |
| SUSE Linux Enterprise Real Time 15 SP4 | Not-Affected |
| SUSE Linux Enterprise Real Time 15 SP5 | Not-Affected |
| SUSE Linux Enterprise Server 11 SP4 | Not-Affected |
| SUSE Linux Enterprise Server 11 SP4-LTSS | Not-Affected |
| SUSE Linux Enterprise Server 15 SP1 | Not-Affected |
| SUSE Linux Enterprise Server 15 SP1-BCL | Not-Affected |
| SUSE Linux Enterprise Server 15 SP1-LTSS | Not-Affected |
| SUSE Linux Enterprise Server 15 SP1-LTSS | Not-Affected |
| SUSE Linux Enterprise Server 15 SP2 | Not-Affected |
| SUSE Linux Enterprise Server 15 SP2-BCL | Not-Affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | Not-Affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | Not-Affected |
| SUSE Linux Enterprise Server 15 SP3 | Not-Affected |
| SUSE Linux Enterprise Server 15 SP3-BCL | Not-Affected |
| SUSE Linux Enterprise Server 15 SP3-LTSS | Not-Affected |
| SUSE Linux Enterprise Server 15 SP3-LTSS | Not-Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP1 | Not-Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP2 | Not-Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | Not-Affected |
| SUSE Manager Proxy 4.0 | Not-Affected |
| SUSE Manager Proxy 4.1 | Not-Affected |
| SUSE Manager Proxy 4.2 | Not-Affected |
| SUSE Manager Proxy 4.3 | Not-Affected |
| SUSE Manager Proxy LTS 4.3 | Not-Affected |
| SUSE Manager Retail Branch Server 4.0 | Not-Affected |
| SUSE Manager Retail Branch Server 4.1 | Not-Affected |
| SUSE Manager Retail Branch Server 4.2 | Not-Affected |
| SUSE Manager Retail Branch Server 4.3 | Not-Affected |
| SUSE Manager Retail Branch Server LTS 4.3 | Not-Affected |
| SUSE Manager Server 4.0 | Not-Affected |
| SUSE Manager Server 4.1 | Not-Affected |
| SUSE Manager Server 4.2 | Not-Affected |
| SUSE Manager Server 4.3 | Not-Affected |
| SUSE Manager Server LTS 4.3 | Not-Affected |
| SUSE Real Time Module 15 SP4 | Not-Affected |
| SUSE Real Time Module 15 SP5 | Not-Affected |
| openSUSE Leap 15.3 | Not-Affected |
| openSUSE Leap 15.4 | Not-Affected |
| openSUSE Leap 15.4 | Not-Affected |
| openSUSE Leap 15.5 | Not-Affected |
| openSUSE Leap 15.5 | Not-Affected |
| openSUSE Leap 15.6 | Not-Affected |
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-45648
GHSA-q3rx-6vfg-rc7w