IB/mthca: Set cleaned CQEs back to HW ownership when cleaning CQ

mthca_cq_clean() updates the CQ consumer index without moving CQEs
back to HW ownership.  As a result, the same WRID might get reported
twice, resulting in a use-after-free.  This was observed in IPoIB CM.
Fix by moving all freed CQEs to HW ownership.

This fixes <https://bugs.openfabrics.org/show_bug.cgi?id=617>

Signed-off-by: Michael S. Tsirkin <mst@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/infiniband/hw/mthca/mthca_cq.c b/drivers/infiniband/hw/mthca/mthca_cq.c
index cf0868f6e96..ca224d018af 100644
--- a/drivers/infiniband/hw/mthca/mthca_cq.c
+++ b/drivers/infiniband/hw/mthca/mthca_cq.c
@@ -284,7 +284,7 @@ void mthca_cq_clean(struct mthca_dev *dev, struct mthca_cq *cq, u32 qpn,
 {
         struct mthca_cqe *cqe;
         u32 prod_index;
-        int nfreed = 0;
+        int i, nfreed = 0;
 
         spin_lock_irq(&cq->lock);
 
@@ -321,6 +321,8 @@ void mthca_cq_clean(struct mthca_dev *dev, struct mthca_cq *cq, u32 qpn,
         }
 
         if (nfreed) {
+                for (i = 0; i < nfreed; ++i)
+                        set_cqe_hw(get_cqe(cq, (cq->cons_index + i) & cq->ibcq.cqe));
                 wmb();
                 cq->cons_index += nfreed;
                 update_cons_index(dev, cq, nfreed);