Wind River Support Network

Description

In the Linux kernel, the following vulnerability has been resolved:  bpf: Use array_map_meta_equal for percpu array inner map replacement  percpu_array_map_ops.map_meta_equal points to the generic bpf_map_meta_equal(), which does not compare max_entries.  When a percpu array serves as an inner map, replacing it with one that has fewer max_entries bypasses the check.  Since percpu_array_map_gen_lookup() inlines the original template's index_mask as a JIT immediate, a lookup on the replacement map can access pptrs[] out of bounds.  Point percpu_array_map_ops.map_meta_equal to array_map_meta_equal(), which already enforces the max_entries equality check.  Add a selftest to verify that replacing a percpu array inner map with a differently-sized one is rejected.