From deea81228ba1c6e77722f534a3d63c50e1757877 Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Thu, 17 May 2018 19:39:31 +0200 Subject: selftests/bpf: check return value of fopen in test_verifier.c Commit 0a6748740368 ("selftests/bpf: Only run tests if !bpf_disabled") forgot to check return value of fopen. This caused some confusion, when running test_verifier (from tools/testing/selftests/bpf/) on an older kernel (< v4.4) as it will simply seqfault. This fix avoids the segfault and prints an error, but allow program to continue. Given the sysctl was introduced in 1be7f75d1668 ("bpf: enable non-root eBPF programs"), we know that the running kernel cannot support unpriv, thus continue with unpriv_disabled = true. Fixes: 0a6748740368 ("selftests/bpf: Only run tests if !bpf_disabled") Signed-off-by: Jesper Dangaard Brouer Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/test_verifier.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'tools') diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index 3e7718b1a9ae..fd7de7eb329e 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -11713,6 +11713,11 @@ static void get_unpriv_disabled() FILE *fd; fd = fopen("/proc/sys/"UNPRIV_SYSCTL, "r"); + if (!fd) { + perror("fopen /proc/sys/"UNPRIV_SYSCTL); + unpriv_disabled = true; + return; + } if (fgets(buf, 2, fd) == buf && atoi(buf)) unpriv_disabled = true; fclose(fd); -- cgit v1.2.3-59-g8ed1b