# CVE-2026-45884: linux: In the Linux kernel, the following vulnerability has been resolved:  apparmor: avoid per-cpu hold underflow in aa_get...

CVE-2026-45884 is fixed in 14 products on 1 platform, first by DEBIAN-CVE-2026-45884, released May 27, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-45884
- Priority: Routine
- CVSS: 5.5 (medium)
- EPSS: 0.0016
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 27, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:  apparmor: avoid per-cpu hold underflow in aa_get_buffer  When aa_get_buffer() pulls from the per-cpu list it unconditionally decrements cache->hold. If hold reaches 0 while count is still non-zero, the unsigned decrement wraps to UINT_MAX. This keeps hold non-zero for a very long time, so aa_put_buffer() never returns buffers to the global list, which can starve other CPUs and force repeated kmalloc(aa_g_path_max) allocations.  Guard the decrement so hold never underflows.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | dtb-aarch64 opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 |
| Linux | kernel-64kb opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 |
| Linux | kernel-64kb sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 |
| Linux | kernel-azure opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 |
| Linux | kernel-azure sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 |
| Linux | kernel-default opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 |
| Linux | kernel-default sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 |
| Linux | kernel-default-base opensuse-leap 16.0 | 6.12.0-160000.36.1.160000.2.17 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 |
| Linux | kernel-default-base sles 16.0 | 6.12.0-160000.36.1.160000.2.17 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 |
| Linux | kernel-docs opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 |
| Linux | kernel-docs sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 |
| Linux | kernel-kvmsmall opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 |
| Linux | kernel-kvmsmall sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 |
| Linux | kernel-obs-build opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 |
| Linux | kernel-obs-qa opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 |
| Linux | kernel-obs-qa sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 |
| Linux | kernel-rt opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 |
| Linux | kernel-source opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 |
| Linux | kernel-source sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 |
| Linux | kernel-syms opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 |
| Linux | kernel-syms sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 |
| Linux | kernel-zfcpdump opensuse-leap 16.0 | 6.12.0-160000.36.1 | [OPENSUSE-SU-2026:21388-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21388-1.md) | Jul 21, 2026 |
| Linux | kernel-zfcpdump sles 16.0 | 6.12.0-160000.36.1 | [SUSE-SU-2026:22835-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22835-1.md) | Jul 21, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.85-1 | [DEBIAN-CVE-2026-45884](https://patchblox.com/security/data/fix/linux/debian-cve-2026-45884.md) | May 27, 2026 |
| Linux | linux Debian 14 | 6.18.14-1 | [DEBIAN-CVE-2026-45884](https://patchblox.com/security/data/fix/linux/debian-cve-2026-45884.md) | May 27, 2026 |

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Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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