diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c
index 797295e792b2fd237beec9f2354972420a83b01d..229d04a83f8561ec08e394f57d8cb5d671bd56ff 100644
--- a/arch/x86/mm/mmap.c
+++ b/arch/x86/mm/mmap.c
@@ -92,13 +92,18 @@ unsigned long arch_mmap_rnd(void)
 static unsigned long mmap_base(unsigned long rnd, unsigned long task_size)
 {
 	unsigned long gap = rlimit(RLIMIT_STACK);
+	unsigned long pad = stack_maxrandom_size(task_size) + stack_guard_gap;
 	unsigned long gap_min, gap_max;
 
+	/* Values close to RLIM_INFINITY can overflow. */
+	if (gap + pad > gap)
+		gap += pad;
+
 	/*
 	 * Top of mmap area (just below the process stack).
 	 * Leave an at least ~128 MB hole with possible stack randomization.
 	 */
-	gap_min = SIZE_128M + stack_maxrandom_size(task_size);
+	gap_min = SIZE_128M;
 	gap_max = (task_size / 6) * 5;
 
 	if (gap < gap_min)