selftests/bpf: Cover scalar arena frees below the base

Add a verifier_arena case that fills a two-page arena, calls
bpf_arena_free_pages() with a scalar address one page below the arena
base, and then verifies that another allocation is still rejected.

Before the runtime guard, the invalid free can repopulate the free
tree with an out-of-domain offset and the final allocation succeeds.

Signed-off-by: Yiyang Chen <chenyy23@mails.tsinghua.edu.cn>
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Link: https://lore.kernel.org/bpf/20260717-c10-031-public-bpf-next-v2-b4-v2-2-54b555443a7c@mails.tsinghua.edu.cn
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

0 files changed, 0 insertions, 0 deletions