[PATCH for-next 4/9] IB/hfi1: Use QPN mask to avoid overflow

Dennis Dalessandro
2017-05-30T00:19:21Z

Ensure we can't come up with an array size that is bigger than the array
by applying the QPN mask before the divide in the free_qpn function.

Reviewed-by: Michael J. Ruhl <michael.j.ruhl-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
drivers/infiniband/sw/rdmavt/qp.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/infiniband/sw/rdmavt/qp.c b/drivers/infiniband/sw/rdmavt/qp.c
index a372afb..2ce0928 100644
--- a/drivers/infiniband/sw/rdmavt/qp.c
+++ b/drivers/infiniband/sw/rdmavt/qp.c
@@ -645,7 +645,7 @@ static void rvt_free_qpn(struct rvt_qpn_table *qpt, u32 qpn)
{
struct rvt_qpn_map *map;

- map = qpt->map + qpn / RVT_BITS_PER_PAGE;
+ map = qpt->map + (qpn & RVT_QPN_MASK) / RVT_BITS_PER_PAGE;
if (map->page)
clear_bit(qpn & RVT_BITS_PER_PAGE_MASK, map->page);
}