CVE-2026-45884
apparmor: avoid per-cpu hold underflow in aa_get_buffer
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.
INFO
Published Date :
May 27, 2026, 2:17 p.m.
Last Modified :
May 27, 2026, 2:48 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Apply the provided Linux kernel patch.
- Update the Linux kernel to a secure version.
- Test the fix to ensure stability.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-45884.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-45884 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-45884
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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CVE-2026-45884 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-45884 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 27, 2026
Action Type Old Value New Value Added 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. Added Reference https://git.kernel.org/stable/c/202824a1f89a9786c20a3d646a7c88d223abb1b2 Added Reference https://git.kernel.org/stable/c/4bcddd0f6b2e52b4c7b520e4d36a115caf5b7169 Added Reference https://git.kernel.org/stable/c/640cf2f09575c9dc344b3f7be2498d31e3923ead Added Reference https://git.kernel.org/stable/c/80c334acc6d0bee8605a358a33e69b4aea1ffb92