Race in qedr_poll_cq, lastest_cqe wasn't protected by lock,
leading to a case where two context's accessing poll_cq at
the same time lead to one of them having a pointer to an old
latest_cqe and reading an invalid cqe element
Signed-off-by: Amit Radzi <Amit.Radzi@xxxxxxxxxx>
Signed-off-by: Michal Kalderon <Michal.Kalderon@xxxxxxxxxx>
Signed-off-by: Ariel Elior <Ariel.Elior@xxxxxxxxxx>
---
drivers/infiniband/hw/qedr/verbs.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/infiniband/hw/qedr/verbs.c b/drivers/infiniband/hw/qedr/verbs.c
index 53f00db..102b9e0 100644
--- a/drivers/infiniband/hw/qedr/verbs.c
+++ b/drivers/infiniband/hw/qedr/verbs.c
@@ -3724,7 +3724,7 @@ int qedr_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *wc)
{
struct qedr_dev *dev = get_qedr_dev(ibcq->device);
struct qedr_cq *cq = get_qedr_cq(ibcq);
- union rdma_cqe *cqe = cq->latest_cqe;
+ union rdma_cqe *cqe;
u32 old_cons, new_cons;
unsigned long flags;
int update = 0;
@@ -3741,6 +3741,7 @@ int qedr_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *wc)
return qedr_gsi_poll_cq(ibcq, num_entries, wc);
spin_lock_irqsave(&cq->cq_lock, flags);
+ cqe = cq->latest_cqe;
old_cons = qed_chain_get_cons_idx_u32(&cq->pbl);
while (num_entries && is_valid_cqe(cq, cqe)) {
struct qedr_qp *qp;
--
2.9.5
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