Re: [PATCH] selftests/bpf: Add test for trie_get_next_key()

[Daniel Borkmann]

Hi Byeonguk,

On 10/24/24 11:08 AM, Byeonguk Jeong wrote:
> Add a test for out-of-bounds write in trie_get_next_key() when a full
> path from root to leaf exists and bpf_map_get_next_key() is called
> with the leaf node. It may crashes the kernel on failure, so please
> run in a VM.
>
> Signed-off-by: Byeonguk Jeong <jungbu2855@xxxxxxxxx>

Could you submit the fix + this selftest as a 2-patch series, otherwise BPF CI
cannot test both in combination (pls make sure subject has [PATCH bpf] so that
our CI adds this on top of the bpf tree).

Right now the CI selftest build threw an error:

  /tmp/work/bpf/bpf/tools/testing/selftests/bpf/map_tests/lpm_trie_map_get_next_key.c: In function ‘test_lpm_trie_map_get_next_key’:
  /tmp/work/bpf/bpf/tools/testing/selftests/bpf/map_tests/lpm_trie_map_get_next_key.c:84:9: error: format not a string literal and no format arguments [-Werror=format-security]
     84 |         CHECK(map_fd == -1, "bpf_map_create(), error:%s\n",
        |         ^~~~~
    TEST-OBJ [test_maps] task_storage_map.test.o
    TEST-OBJ [test_progs] access_variable_array.test.o
  cc1: all warnings being treated as errors
    TEST-OBJ [test_progs] align.test.o
    TEST-OBJ [test_progs] arena_atomics.test.o
  make: *** [Makefile:765: /tmp/work/bpf/bpf/tools/testing/selftests/bpf/lpm_trie_map_get_next_key.test.o] Error 1
  make: *** Waiting for unfinished jobs....
    GEN-SKEL [test_progs-no_alu32] test_usdt.skel.h
  make: Leaving directory '/tmp/work/bpf/bpf/tools/testing/selftests/bpf'

Also on quick glance, please use ASSERT_*() macros instead of CHECK() as the
latter is deprecated.

Thanks,
Daniel