Threats Tagged '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.

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.