In the Linux kernel, the following vulnerability has been resolved:
selinux: reject a class permission count below its inherited common
security_get_permissions() maps an inherited common’s permissions into
an array sized by the class’s own permissions.nprim, but class_read()
takes that nprim verbatim from the policy image and never checks that it
covers the common. A class that inherits a common of N permissions while
declaring a smaller nprim is accepted, and on load the common’s
permissions are written past the class-sized array — an out-of-bounds
heap write.
Reject a class whose permission count is below its inherited common’s.
Well-formed policies, where the class count already includes the
inherited permissions, are unaffected.
