CVE-2026-45884

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxea9bae12d02819556db63348db8bd8441eb316f2 < 202824a1f89a9786c20a3d646a7c88d223abb1b2affected
LinuxLinuxea9bae12d02819556db63348db8bd8441eb316f2 < 80c334acc6d0bee8605a358a33e69b4aea1ffb92affected
LinuxLinuxea9bae12d02819556db63348db8bd8441eb316f2 < 4bcddd0f6b2e52b4c7b520e4d36a115caf5b7169affected
LinuxLinuxea9bae12d02819556db63348db8bd8441eb316f2 < 640cf2f09575c9dc344b3f7be2498d31e3923eadaffected
LinuxLinux6.7affected
LinuxLinux0 < 6.7unaffected
LinuxLinux6.12.75 <= 6.12.*unaffected
LinuxLinux6.18.14 <= 6.18.*unaffected
LinuxLinux6.19.4 <= 6.19.*unaffected
LinuxLinux7.0 <= *unaffected

Weaknesses

References