A vulnerability in the Linux kernel's netlink subsystem allowed an unprivileged user to infer kernel memory layout details by exploiting how network namespace pointers were hashed. This could enable recovery of the address of init_net, a kernel structure. The issue was fixed by replacing the use of raw network namespace pointers with a unique, non-address net_cookie value in hash keys, preventing information leakage. The fix is compatible with older stable kernels and preserves namespace separation without changing public table walkers.