From e3524b269e451cff68b19f32b15448933a53a4f4 Mon Sep 17 00:00:00 2001 From: Bryan Tan Date: Wed, 20 Dec 2017 09:51:40 -0800 Subject: [PATCH] RDMA/vmw_pvrdma: Avoid use after free due to QP/CQ/SRQ destroy The use of wait queues in vmw_pvrdma for handling concurrent access to a resource leaves a race condition which can cause a use after free bug. Fix this by using the pattern from other drivers, complete() protected by dec_and_test to ensure complete() is called only once. Fixes: 29c8d9eba550 ("IB: Add vmw_pvrdma driver") Signed-off-by: Bryan Tan Signed-off-by: Jason Gunthorpe --- 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 63bc2efc34eb..4f7bd3b6a315 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 3562c0c30492..e529622cefad 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 @@ err_cq: 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 1f4e18717a00..e92681878c93 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 dceebc623d96..4059308e1454 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 a2b1a3c115f2..5acebb1ef631 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); -- 2.30.2