The use of wait queues in vmw_pvrdma for handling concurrent
access to a resource leaves a possible use after free bug.
Fix this by using completions instead, and also using
atomic_dec_and_test to ensure complete() is called only once.
Fixes: 29c8d9eba550 ("IB: Add vmw_pvrdma driver")
Signed-off-by: Bryan Tan <bryantan@xxxxxxxxxx>
---
drivers/infiniband/hw/vmw_pvrdma/pvrdma.h | 6 +++---
drivers/infiniband/hw/vmw_pvrdma/pvrdma_cq.c | 7 ++++---
drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c | 17 +++++++----------
drivers/infiniband/hw/vmw_pvrdma/pvrdma_qp.c | 7 ++++---
drivers/infiniband/hw/vmw_pvrdma/pvrdma_srq.c | 7 ++++---
5 files changed, 22 insertions(+), 22 deletions(-)
diff --git a/drivers/infiniband/hw/vmw_pvrdma/pvrdma.h b/drivers/infiniband/hw/vmw_pvrdma/pvrdma.h
index 63bc2ef..4f7bd3b6 100644
--- a/drivers/infiniband/hw/vmw_pvrdma/pvrdma.h
+++ b/drivers/infiniband/hw/vmw_pvrdma/pvrdma.h
@@ -94,7 +94,7 @@ struct pvrdma_cq {
u32 cq_handle;
bool is_kernel;
atomic_t refcnt;
- wait_queue_head_t wait;
+ struct completion free;
};
struct pvrdma_id_table {
@@ -175,7 +175,7 @@ struct pvrdma_srq {
u32 srq_handle;
int npages;
refcount_t refcnt;
- wait_queue_head_t wait;
+ struct completion free;
};
struct pvrdma_qp {
@@ -197,7 +197,7 @@ struct pvrdma_qp {
bool is_kernel;
struct mutex mutex; /* QP state mutex. */
atomic_t refcnt;
- wait_queue_head_t wait;
+ struct completion free;
};
struct pvrdma_dev {
diff --git a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_cq.c b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_cq.c
index 3562c0c..e529622 100644
--- a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_cq.c
+++ b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_cq.c
@@ -179,7 +179,7 @@ struct ib_cq *pvrdma_create_cq(struct ib_device *ibdev,
pvrdma_page_dir_insert_umem(&cq->pdir, cq->umem, 0);
atomic_set(&cq->refcnt, 1);
- init_waitqueue_head(&cq->wait);
+ init_completion(&cq->free);
spin_lock_init(&cq->cq_lock);
memset(cmd, 0, sizeof(*cmd));
@@ -230,8 +230,9 @@ struct ib_cq *pvrdma_create_cq(struct ib_device *ibdev,
static void pvrdma_free_cq(struct pvrdma_dev *dev, struct pvrdma_cq *cq)
{
- atomic_dec(&cq->refcnt);
- wait_event(cq->wait, !atomic_read(&cq->refcnt));
+ if (atomic_dec_and_test(&cq->refcnt))
+ complete(&cq->free);
+ wait_for_completion(&cq->free);
if (!cq->is_kernel)
ib_umem_release(cq->umem);
diff --git a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c
index 1f4e187..e926818 100644
--- a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c
+++ b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_main.c
@@ -346,9 +346,8 @@ static void pvrdma_qp_event(struct pvrdma_dev *dev, u32 qpn, int type)
ibqp->event_handler(&e, ibqp->qp_context);
}
if (qp) {
- atomic_dec(&qp->refcnt);
- if (atomic_read(&qp->refcnt) == 0)
- wake_up(&qp->wait);
+ if (atomic_dec_and_test(&qp->refcnt))
+ complete(&qp->free);
}
}
@@ -373,9 +372,8 @@ static void pvrdma_cq_event(struct pvrdma_dev *dev, u32 cqn, int type)
ibcq->event_handler(&e, ibcq->cq_context);
}
if (cq) {
- atomic_dec(&cq->refcnt);
- if (atomic_read(&cq->refcnt) == 0)
- wake_up(&cq->wait);
+ if (atomic_dec_and_test(&cq->refcnt))
+ complete(&cq->free);
}
}
@@ -404,7 +402,7 @@ static void pvrdma_srq_event(struct pvrdma_dev *dev, u32 srqn, int type)
}
if (srq) {
if (refcount_dec_and_test(&srq->refcnt))
- wake_up(&srq->wait);
+ complete(&srq->free);
}
}
@@ -539,9 +537,8 @@ static irqreturn_t pvrdma_intrx_handler(int irq, void *dev_id)
if (cq && cq->ibcq.comp_handler)
cq->ibcq.comp_handler(&cq->ibcq, cq->ibcq.cq_context);
if (cq) {
- atomic_dec(&cq->refcnt);
- if (atomic_read(&cq->refcnt))
- wake_up(&cq->wait);
+ if (atomic_dec_and_test(&cq->refcnt))
+ complete(&cq->free);
}
pvrdma_idx_ring_inc(&ring->cons_head, ring_slots);
}
diff --git a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_qp.c b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_qp.c
index dceebc6..4059308 100644
--- a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_qp.c
+++ b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_qp.c
@@ -246,7 +246,7 @@ struct ib_qp *pvrdma_create_qp(struct ib_pd *pd,
spin_lock_init(&qp->rq.lock);
mutex_init(&qp->mutex);
atomic_set(&qp->refcnt, 1);
- init_waitqueue_head(&qp->wait);
+ init_completion(&qp->free);
qp->state = IB_QPS_RESET;
@@ -428,8 +428,9 @@ static void pvrdma_free_qp(struct pvrdma_qp *qp)
pvrdma_unlock_cqs(scq, rcq, &scq_flags, &rcq_flags);
- atomic_dec(&qp->refcnt);
- wait_event(qp->wait, !atomic_read(&qp->refcnt));
+ if (atomic_dec_and_test(&qp->refcnt))
+ complete(&qp->free);
+ wait_for_completion(&qp->free);
if (!qp->is_kernel) {
if (qp->rumem)
diff --git a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_srq.c b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_srq.c
index a2b1a3c..5acebb1 100644
--- a/drivers/infiniband/hw/vmw_pvrdma/pvrdma_srq.c
+++ b/drivers/infiniband/hw/vmw_pvrdma/pvrdma_srq.c
@@ -149,7 +149,7 @@ struct ib_srq *pvrdma_create_srq(struct ib_pd *pd,
spin_lock_init(&srq->lock);
refcount_set(&srq->refcnt, 1);
- init_waitqueue_head(&srq->wait);
+ init_completion(&srq->free);
dev_dbg(&dev->pdev->dev,
"create shared receive queue from user space\n");
@@ -236,8 +236,9 @@ static void pvrdma_free_srq(struct pvrdma_dev *dev, struct pvrdma_srq *srq)
dev->srq_tbl[srq->srq_handle] = NULL;
spin_unlock_irqrestore(&dev->srq_tbl_lock, flags);
- if (!refcount_dec_and_test(&srq->refcnt))
- wait_event(srq->wait, !refcount_read(&srq->refcnt));
+ if (refcount_dec_and_test(&srq->refcnt))
+ complete(&srq->free);
+ wait_for_completion(&srq->free);
/* There is no support for kernel clients, so this is safe. */
ib_umem_release(srq->umem);
--
1.8.5.6
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