diff --git a/drivers/staging/android/lowmemorykiller.c b/drivers/staging/android/lowmemorykiller.c
index feafa172b155..defddf5f80dd 100644
--- a/drivers/staging/android/lowmemorykiller.c
+++ b/drivers/staging/android/lowmemorykiller.c
@@ -156,20 +156,27 @@ static unsigned long lowmem_scan(struct shrinker *s, struct shrink_control *sc)
 			     p->pid, p->comm, oom_score_adj, tasksize);
 	}
 	if (selected) {
-		lowmem_print(1, "send sigkill to %d (%s), adj %hd, size %d\n",
-			     selected->pid, selected->comm,
-			     selected_oom_score_adj, selected_tasksize);
-		lowmem_deathpending_timeout = jiffies + HZ;
+		task_lock(selected);
+		if (!selected->mm) {
+			/* Already exited, cannot do mark_tsk_oom_victim() */
+			task_unlock(selected);
+			goto out;
+		}
 		/*
 		 * FIXME: lowmemorykiller shouldn't abuse global OOM killer
 		 * infrastructure. There is no real reason why the selected
 		 * task should have access to the memory reserves.
 		 */
 		mark_tsk_oom_victim(selected);
+		task_unlock(selected);
+		lowmem_print(1, "send sigkill to %d (%s), adj %hd, size %d\n",
+			     selected->pid, selected->comm,
+			     selected_oom_score_adj, selected_tasksize);
+		lowmem_deathpending_timeout = jiffies + HZ;
 		send_sig(SIGKILL, selected, 0);
 		rem += selected_tasksize;
 	}
-
+out:
 	lowmem_print(4, "lowmem_scan %lu, %x, return %lu\n",
 		     sc->nr_to_scan, sc->gfp_mask, rem);
 	rcu_read_unlock();