diff --git a/arch/um/kernel/reboot.c b/arch/um/kernel/reboot.c
index 4d93dff6b3713e321a66f49ef160d3da4380e7a2..66d754c46e7b048492f7587fdcbe08fed2b4630d 100644
--- a/arch/um/kernel/reboot.c
+++ b/arch/um/kernel/reboot.c
@@ -4,6 +4,7 @@
  */
 
 #include "linux/sched.h"
+#include "linux/spinlock.h"
 #include "linux/slab.h"
 #include "kern_util.h"
 #include "os.h"
@@ -22,6 +23,7 @@ static void kill_off_processes(void)
 		struct task_struct *p;
 		int pid;
 
+		read_lock(&tasklist_lock);
 		for_each_process(p) {
 			if (p->mm == NULL)
 				continue;
@@ -29,6 +31,7 @@ static void kill_off_processes(void)
 			pid = p->mm->context.id.u.pid;
 			os_kill_ptraced_process(pid, 1);
 		}
+		read_unlock(&tasklist_lock);
 	}
 }