userns: Convert the move_pages, and migrate_pages permission checks t…

…o use uid_eq

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

init/Kconfig

@@ -865,8 +865,6 @@ config UIDGID_CONVERTED
 
 	# List of kernel pieces that need user namespace work
 	# Features
-	depends on MIGRATION = n
-	depends on NUMA = n
 	depends on SYSVIPC = n
 	depends on IMA = n
 	depends on EVM = n

mm/mempolicy.c

@@ -1334,8 +1334,8 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode,
 	 * userid as the target process.
 	 */
 	tcred = __task_cred(task);
-	if (cred->euid != tcred->suid && cred->euid != tcred->uid &&
-	    cred->uid  != tcred->suid && cred->uid  != tcred->uid &&
+	if (!uid_eq(cred->euid, tcred->suid) && !uid_eq(cred->euid, tcred->uid) &&
+	    !uid_eq(cred->uid,  tcred->suid) && !uid_eq(cred->uid,  tcred->uid) &&
 	    !capable(CAP_SYS_NICE)) {
 		rcu_read_unlock();
 		err = -EPERM;

mm/migrate.c

@@ -1371,8 +1371,8 @@ SYSCALL_DEFINE6(move_pages, pid_t, pid, unsigned long, nr_pages,
 	 * userid as the target process.
 	 */
 	tcred = __task_cred(task);
-	if (cred->euid != tcred->suid && cred->euid != tcred->uid &&
-	    cred->uid  != tcred->suid && cred->uid  != tcred->uid &&
+	if (!uid_eq(cred->euid, tcred->suid) && !uid_eq(cred->euid, tcred->uid) &&
+	    !uid_eq(cred->uid,  tcred->suid) && !uid_eq(cred->uid,  tcred->uid) &&
 	    !capable(CAP_SYS_NICE)) {
 		rcu_read_unlock();
 		err = -EPERM;