net: Update the sysctl permissions handler to test effective uid/gid

commit 2433c8f094a008895e66f25bd1773cdb01c91d01 upstream.

Modify the code to use current_euid(), and in_egroup_p, as in done
in fs/proc/proc_sysctl.c:test_perm()

Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reported-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/sysctl_net.c b/net/sysctl_net.c
index 9bc6db04..e7000be 100644
--- a/net/sysctl_net.c
+++ b/net/sysctl_net.c
@@ -47,12 +47,12 @@
 
 	/* Allow network administrator to have same access as root. */
 	if (ns_capable(net->user_ns, CAP_NET_ADMIN) ||
-	    uid_eq(root_uid, current_uid())) {
+	    uid_eq(root_uid, current_euid())) {
 		int mode = (table->mode >> 6) & 7;
 		return (mode << 6) | (mode << 3) | mode;
 	}
 	/* Allow netns root group to have the same access as the root group */
-	if (gid_eq(root_gid, current_gid())) {
+	if (in_egroup_p(root_gid)) {
 		int mode = (table->mode >> 3) & 7;
 		return (mode << 3) | mode;
 	}