Use-after-free in Linux kernel AppArmor rawdata handling

CVE-2026-23410 is a Linux kernel AppArmor vulnerability caused by a race condition in raw profile data handling that can lead to a use-after-free. AppArmor exposes members of struct aa_loaddata through securityfs raw_data entries. Because the associated rawdata inodes were not refcounted, an attacker could race open() on one of these rawdata files against removal of the last reference to the same rawdata object, for example by removing the corresponding AppArmor profile. In the vulnerable path, seq_rawdata_open() dereferences inode->i_private after the underlying struct aa_loaddata may already have been freed, leaving i_private as a dangling pointer and causing access to freed memory. The upstream fix changed AppArmor rawdata lifetime management to a double-refcount scheme so the profile reference breaks the circular dependency while rawdata is only freed after all inode references are released.