wrapper: fix segfault in cgroup_set_value_uint64()

The second argument passed to cgroup_set_value_uint64() is of type
char * and the user might pass NULL in the place of the argument,
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_set_value_uint64(cgc, NULL, 512);
         // 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 afb6c6ab0ca1c7812bb8229c7054ba4917402f67)

diff --git a/src/wrapper.c b/src/wrapper.c
index fc8ed181dd1d8452b8c06f85a2fc92f8009d8d56..a8b9a54f39624b656a6696f46767a198c92b5c4c 100644 (file)
--- a/src/wrapper.c
+++ b/src/wrapper.c
@@ -552,7 +552,7 @@ int cgroup_set_value_uint64(struct cgroup_controller *controller, const char *na
        int ret;
        int i;
 
-       if (!controller)
+       if (!controller || !name)
                return ECGINVAL;
 
        for (i = 0; i < controller->index; i++) {