diff --git a/arch/um/kernel/reboot.c b/arch/um/kernel/reboot.c
index 1411f4e79f9a..3d15243ce692 100644
--- a/arch/um/kernel/reboot.c
+++ b/arch/um/kernel/reboot.c
@@ -6,6 +6,7 @@
 #include "linux/sched.h"
 #include "linux/spinlock.h"
 #include "linux/slab.h"
+#include "linux/oom.h"
 #include "kern_util.h"
 #include "os.h"
 #include "skas.h"
@@ -25,13 +26,13 @@ static void kill_off_processes(void)
 
 		read_lock(&tasklist_lock);
 		for_each_process(p) {
-			task_lock(p);
-			if (!p->mm) {
-				task_unlock(p);
+			struct task_struct *t;
+
+			t = find_lock_task_mm(p);
+			if (!t)
 				continue;
-			}
-			pid = p->mm->context.id.u.pid;
-			task_unlock(p);
+			pid = t->mm->context.id.u.pid;
+			task_unlock(t);
 			os_kill_ptraced_process(pid, 1);
 		}
 		read_unlock(&tasklist_lock);