1 files changed, 5 insertions, 2 deletions

diff --git a/arch/um/kernel/reboot.c b/arch/um/kernel/reboot.c
index 66d754c46e7..1411f4e79f9 100644
--- a/arch/um/kernel/reboot.c
+++ b/arch/um/kernel/reboot.c
@@ -25,10 +25,13 @@ static void kill_off_processes(void)
 
                 read_lock(&tasklist_lock);
                 for_each_process(p) {
-                        if (p->mm == NULL)
+                        task_lock(p);
+                        if (!p->mm) {
+                                task_unlock(p);
                                 continue;
-
+                        }
                         pid = p->mm->context.id.u.pid;
+                        task_unlock(p);
                         os_kill_ptraced_process(pid, 1);
                 }
                 read_unlock(&tasklist_lock);