1 files changed, 8 insertions, 1 deletions

diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c
index 7c195d972bf0..8d86a8b5522a 100644
--- a/net/sched/sch_qfq.c
+++ b/net/sched/sch_qfq.c
@@ -821,7 +821,14 @@ static void qfq_make_eligible(struct qfq_sched *q)
         unsigned long old_vslot = q->oldV >> q->min_slot_shift;
 
         if (vslot != old_vslot) {
-                unsigned long mask = (1ULL << fls(vslot ^ old_vslot)) - 1;
+                unsigned long mask;
+                int last_flip_pos = fls(vslot ^ old_vslot);
+
+                if (last_flip_pos > 31) /* higher than the number of groups */
+                        mask = ~0UL;    /* make all groups eligible */
+                else
+                        mask = (1UL << last_flip_pos) - 1;
+
                 qfq_move_groups(q, mask, IR, ER);
                 qfq_move_groups(q, mask, IB, EB);
         }