selftests/bpf: Close the file descriptor to avoid resource leaks

JIRA: https://issues.redhat.com/browse/RHEL-78203

commit be2fea9
Author: Malaya Kumar Rout <malayarout91@gmail.com>
Date:   Mon Apr 21 23:14:05 2025 +0530

    selftests/bpf: Close the file descriptor to avoid resource leaks
    
    Static analysis found an issue in bench_htab_mem.c and sk_assign.c
    
    cppcheck output before this patch:
    tools/testing/selftests/bpf/benchs/bench_htab_mem.c:284:3: error: Resource leak: fd [resourceLeak]
    tools/testing/selftests/bpf/prog_tests/sk_assign.c:41:3: error: Resource leak: tc [resourceLeak]
    
    cppcheck output after this patch:
    No resource leaks found
    
    Fix the issue by closing the file descriptors fd and tc.
    
    Signed-off-by: Malaya Kumar Rout <malayarout91@gmail.com>
    Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
    Link: https://lore.kernel.org/bpf/20250421174405.26080-1-malayarout91@gmail.com

Signed-off-by: Viktor Malik <vmalik@redhat.com>

Author: viktormalik

tools/testing/selftests/bpf/benchs/bench_htab_mem.c

@@ -279,15 +279,14 @@ static void htab_mem_read_mem_cgrp_file(const char *name, unsigned long *value)
 	}
 
 	got = read(fd, buf, sizeof(buf) - 1);
+	close(fd);
 	if (got <= 0) {
 		*value = 0;
 		return;
 	}
 	buf[got] = 0;
 
 	*value = strtoull(buf, NULL, 0);
-
-	close(fd);
 }
 
 static void htab_mem_measure(struct bench_res *res)

tools/testing/selftests/bpf/prog_tests/sk_assign.c

@@ -37,8 +37,10 @@ configure_stack(void)
 	tc = popen("tc -V", "r");
 	if (CHECK_FAIL(!tc))
 		return false;
-	if (CHECK_FAIL(!fgets(tc_version, sizeof(tc_version), tc)))
+	if (CHECK_FAIL(!fgets(tc_version, sizeof(tc_version), tc))) {
+		pclose(tc);
 		return false;
+	}
 	if (strstr(tc_version, ", libbpf "))
 		prog = "test_sk_assign_libbpf.bpf.o";
 	else