CVE-2026-90231

Summary

In the Linux kernel, the following vulnerability has been resolved:

apparmor: fix unconfined user namespace restriction forced stack

If a task is already confined by a stack the unprivileged transition restriction on unconfined is not correctly, applied. This results in an escape if two transitions through an unconfined profile can be executed.

Fix this by pushing the check into the per profile label build. The check will always be done against unconfined and result in a stack of just the unconfined component when necessary.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux2d9da9b188b8cd3b579d7ef5ba5d334be9dd38fc < 7d1099b86356df81c379159bfb8a598aaf83ce81affected
LinuxLinux2d9da9b188b8cd3b579d7ef5ba5d334be9dd38fc < 7da0bdf0610f6d35bbb061536a47fc41646306f0affected
LinuxLinux2d9da9b188b8cd3b579d7ef5ba5d334be9dd38fc < 08c2f7c8d4b1434cfae006f3daf4d1bce330b57baffected
LinuxLinux6.7affected
LinuxLinux0 < 6.7unaffected
LinuxLinux6.18.52 <= 6.18.*unaffected
LinuxLinux7.2.6 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References