1 files changed, 50 insertions, 18 deletions

diff --git a/include/net/scm.h b/include/net/scm.h
index 8360e47aa7e..262532d111f 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -10,27 +10,34 @@
 /* Well, we should have at least one descriptor open
  * to accept passed FDs 8)
  */
-#define SCM_MAX_FD	255
+#define SCM_MAX_FD	253
+
+struct scm_creds {
+	u32	pid;
+	kuid_t	uid;
+	kgid_t	gid;
+};
 
 struct scm_fp_list {
-	struct list_head	list;
-	int			count;
+	short			count;
+	short			max;
 	struct file		*fp[SCM_MAX_FD];
 };
 
 struct scm_cookie {
-	struct ucred		creds;		/* Skb credentials	*/
+	struct pid		*pid;		/* Skb credentials */
 	struct scm_fp_list	*fp;		/* Passed files		*/
+	struct scm_creds	creds;		/* Skb credentials	*/
 #ifdef CONFIG_SECURITY_NETWORK
 	u32			secid;		/* Passed security ID 	*/
 #endif
 };
 
-extern void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm);
-extern void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm);
-extern int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm);
-extern void __scm_destroy(struct scm_cookie *scm);
-extern struct scm_fp_list * scm_fp_dup(struct scm_fp_list *fpl);
+void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm);
+void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm);
+int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm);
+void __scm_destroy(struct scm_cookie *scm);
+struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl);
 
 #ifdef CONFIG_SECURITY_NETWORK
 static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
@@ -42,20 +49,36 @@ static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_co
 { }
 #endif /* CONFIG_SECURITY_NETWORK */
 
+static __inline__ void scm_set_cred(struct scm_cookie *scm,
+				    struct pid *pid, kuid_t uid, kgid_t gid)
+{
+	scm->pid  = get_pid(pid);
+	scm->creds.pid = pid_vnr(pid);
+	scm->creds.uid = uid;
+	scm->creds.gid = gid;
+}
+
+static __inline__ void scm_destroy_cred(struct scm_cookie *scm)
+{
+	put_pid(scm->pid);
+	scm->pid  = NULL;
+}
+
 static __inline__ void scm_destroy(struct scm_cookie *scm)
 {
-	if (scm && scm->fp)
+	scm_destroy_cred(scm);
+	if (scm->fp)
 		__scm_destroy(scm);
 }
 
 static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
-			       struct scm_cookie *scm)
+			       struct scm_cookie *scm, bool forcecreds)
 {
-	struct task_struct *p = current;
-	scm->creds.uid = current_uid();
-	scm->creds.gid = current_gid();
-	scm->creds.pid = task_tgid_vnr(p);
-	scm->fp = NULL;
+	memset(scm, 0, sizeof(*scm));
+	scm->creds.uid = INVALID_UID;
+	scm->creds.gid = INVALID_GID;
+	if (forcecreds)
+		scm_set_cred(scm, task_tgid(current), current_uid(), current_gid());
 	unix_get_peersec_dgram(sock, scm);
 	if (msg->msg_controllen <= 0)
 		return 0;
@@ -93,8 +116,17 @@ static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg,
 		return;
 	}
 
-	if (test_bit(SOCK_PASSCRED, &sock->flags))
-		put_cmsg(msg, SOL_SOCKET, SCM_CREDENTIALS, sizeof(scm->creds), &scm->creds);
+	if (test_bit(SOCK_PASSCRED, &sock->flags)) {
+		struct user_namespace *current_ns = current_user_ns();
+		struct ucred ucreds = {
+			.pid = scm->creds.pid,
+			.uid = from_kuid_munged(current_ns, scm->creds.uid),
+			.gid = from_kgid_munged(current_ns, scm->creds.gid),
+		};
+		put_cmsg(msg, SOL_SOCKET, SCM_CREDENTIALS, sizeof(ucreds), &ucreds);
+	}
+
+	scm_destroy_cred(scm);
 
 	scm_passec(sock, msg, scm);