A vulnerability in the Linux kernel's AppArmor component involves an unsigned integer underflow in the per-CPU buffer hold counter within the… (CVE-2026-45884)
A vulnerability in the Linux kernel's AppArmor component involves an unsigned integer underflow in the per-CPU buffer hold counter within the aa_get_buffer() function. This underflow causes the hold counter to wrap to a very large value, preventing buffers from being returned to the global list. As a result, other CPUs may be starved of buffers, leading to repeated memory allocations and potential denial of service. The issue has been fixed by adding a guard to prevent the hold counter from underflowing.
AI Analysis
Technical Summary
The Linux kernel's AppArmor module had a vulnerability where the aa_get_buffer() function unconditionally decremented a per-CPU cache hold counter. If this counter reached zero while the buffer count was still non-zero, the unsigned decrement caused an underflow, wrapping the hold counter to UINT_MAX. This prevented aa_put_buffer() from returning buffers to the global list, causing buffer starvation on other CPUs and forcing repeated memory allocations (kmalloc) of size aa_g_path_max. The fix involves guarding the decrement operation to prevent the hold counter from underflowing.
Potential Impact
This vulnerability does not affect confidentiality or integrity but impacts availability by causing buffer starvation and forcing repeated memory allocations, potentially leading to denial of service conditions on affected systems.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance.
A vulnerability in the Linux kernel's AppArmor component involves an unsigned integer underflow in the per-CPU buffer hold counter within the… (CVE-2026-45884)
Description
A vulnerability in the Linux kernel's AppArmor component involves an unsigned integer underflow in the per-CPU buffer hold counter within the aa_get_buffer() function. This underflow causes the hold counter to wrap to a very large value, preventing buffers from being returned to the global list. As a result, other CPUs may be starved of buffers, leading to repeated memory allocations and potential denial of service. The issue has been fixed by adding a guard to prevent the hold counter from underflowing.
CVSS v3.1
Score 5.5medium
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel's AppArmor module had a vulnerability where the aa_get_buffer() function unconditionally decremented a per-CPU cache hold counter. If this counter reached zero while the buffer count was still non-zero, the unsigned decrement caused an underflow, wrapping the hold counter to UINT_MAX. This prevented aa_put_buffer() from returning buffers to the global list, causing buffer starvation on other CPUs and forcing repeated memory allocations (kmalloc) of size aa_g_path_max. The fix involves guarding the decrement operation to prevent the hold counter from underflowing.
Potential Impact
This vulnerability does not affect confidentiality or integrity but impacts availability by causing buffer starvation and forcing repeated memory allocations, potentially leading to denial of service conditions on affected systems.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-8h74-qh3g-94fx
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-45884"]
- Ecosystems
- []
- Database Specific Severity
- MODERATE
- Cvss Version
- 3.1
Threat ID: 6a3ef7ef27e9c79719034b7f
Added to database: 06/26/2026, 22:06:39 UTC
Last enriched: 06/26/2026, 22:49:55 UTC
Last updated: 07/31/2026, 19:24:46 UTC
Views: 4
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