From: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Date: Fri, 3 Mar 2023 04:31:41 +0000 (+0530)
Subject: wrapper: fix segfault in cgroup_get_value_int64()
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3e80806708d7b4aa85acd32fe5375874a71b201c;p=thirdparty%2Flibcgroup.git

wrapper: fix segfault in cgroup_get_value_int64()

The second and third arguments passed to cgroup_get_value_int64() are of
type char * and the user might pass NULL in place of one or both of the
arguments, causing a segfault. The reason is, argument values are used
without checks, fix it by checking for NULL pointers before proceeding.

Reproducer:
-----------
 #include <stdlib.h>
 #include <libcgroup.h>

 int main(void)
 {
 	struct cgroup_controller *cgc;
 	struct cgroup *cgrp;
 	int ret;

 	ret = cgroup_init();
 	if (ret)
 		exit(1);

 	cgrp = cgroup_new_cgroup("fuzzer");
 	if (!cgrp)
 		exit(1);

 	cgc = cgroup_add_controller(cgrp, "cpu");
 	if (!cgc)
 		exit(1);

 	ret = cgroup_add_value_string(cgc, "cpu.shares", "512");
 	if (ret)
 		exit (1);

 	cgroup_get_value_int64(cgc, NULL, NULL);
 	// should not reach here.
 	return 0;
 }

Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>
(cherry picked from commit cf616d09d740e7a890e8af3ec9d5799f1713718b)
---

diff --git a/src/wrapper.c b/src/wrapper.c
index 677ba2a0..fc8ed181 100644
--- a/src/wrapper.c
+++ b/src/wrapper.c
@@ -483,7 +483,7 @@ int cgroup_get_value_int64(struct cgroup_controller *controller, const char *nam
 {
 	int i;
 
-	if (!controller)
+	if (!controller || !name || !value)
 		return ECGINVAL;
 
 	for (i = 0; i < controller->index; i++) {