From: Yonghong Song Date: Wed, 11 Jun 2025 16:21:03 +0000 (-0700) Subject: selftests/bpf: Fix cgroup_mprog_ordering failure due to uninitialized variable X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=517b088a846b3ce56b3ff07cdf24cd68c89b3a9e;p=thirdparty%2Fkernel%2Flinux.git selftests/bpf: Fix cgroup_mprog_ordering failure due to uninitialized variable On arm64, the cgroup_mprog_ordering selftest failed with test_progs run when building with clang compiler. The reason is due to socklen_t optlen not initialized. In kernel function do_ip_getsockopt(), we have if (copy_from_sockptr(&len, optlen, sizeof(int))) return -EFAULT; if (len < 0) return -EINVAL; The above 'len' variable is a negative value and hence the test failed. But the test is okay on x86_64. I checked the x86_64 asm code and I didn't see explicit initialization of 'optlen' but its value is 0 so kernel didn't return error. This should be a pure luck. Fix the bug by initializing 'oplen' var properly. Fixes: e422d5f118e4 ("selftests/bpf: Add two selftests for mprog API based cgroup progs") Signed-off-by: Yonghong Song Link: https://lore.kernel.org/r/20250611162103.1623692-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov --- diff --git a/tools/testing/selftests/bpf/prog_tests/cgroup_mprog_ordering.c b/tools/testing/selftests/bpf/prog_tests/cgroup_mprog_ordering.c index 4a4e9710b474a..a36d2e968bc5b 100644 --- a/tools/testing/selftests/bpf/prog_tests/cgroup_mprog_ordering.c +++ b/tools/testing/selftests/bpf/prog_tests/cgroup_mprog_ordering.c @@ -12,7 +12,7 @@ static int run_getsockopt_test(int cg_parent, int sock_fd, bool has_relative_fd) struct cgroup_preorder *skel = NULL; struct bpf_program *prog; __u8 *result, buf; - socklen_t optlen; + socklen_t optlen = 1; int err = 0; skel = cgroup_preorder__open_and_load();