diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 09228639b83dd7970154eba13c69eeec73422e4d..7366e9d63cee7d8658e9fed949a2fe7b22519c6f 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1402,8 +1402,10 @@ static int show_numa_map(struct seq_file *m, void *v, int is_pid)
 	walk.mm = mm;
 
 	pol = get_vma_policy(task, vma, vma->vm_start);
-	mpol_to_str(buffer, sizeof(buffer), pol);
+	n = mpol_to_str(buffer, sizeof(buffer), pol);
 	mpol_cond_put(pol);
+	if (n < 0)
+		return n;
 
 	seq_printf(m, "%08lx %s", vma->vm_start, buffer);