RDMA/siw: free siw_base_qp in kref release routine

As siw_free_qp() is the last routine to access 'siw_base_qp' structure,
freeing this structure early in siw_destroy_qp() could cause
touch-after-free issue.
Hence, moved kfree(siw_base_qp) from siw_destroy_qp() to siw_free_qp().

Fixes: 303ae1cdfdf7 ("rdma/siw: application interface")
Signed-off-by: Krishnamraju Eraparaju <krishna2@chelsio.com>
Link: https://lore.kernel.org/r/20191007104229.29412-1-krishna2@chelsio.com
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/sw/siw/siw_qp.c b/drivers/infiniband/sw/siw/siw_qp.c
index 52d402f39df93c28771d09ee9b673ea40303101f..b4317480cee7486d2f461d4b870cd801bc636d93 100644 (file)
--- a/drivers/infiniband/sw/siw/siw_qp.c
+++ b/drivers/infiniband/sw/siw/siw_qp.c
@@ -1312,6 +1312,7 @@ int siw_qp_add(struct siw_device *sdev, struct siw_qp *qp)
 void siw_free_qp(struct kref *ref)
 {
        struct siw_qp *found, *qp = container_of(ref, struct siw_qp, ref);
+       struct siw_base_qp *siw_base_qp = to_siw_base_qp(qp->ib_qp);
        struct siw_device *sdev = qp->sdev;
        unsigned long flags;
 
@@ -1334,4 +1335,5 @@ void siw_free_qp(struct kref *ref)
        atomic_dec(&sdev->num_qp);
        siw_dbg_qp(qp, "free QP\n");
        kfree_rcu(qp, rcu);
+       kfree(siw_base_qp);
 }

diff --git a/drivers/infiniband/sw/siw/siw_verbs.c b/drivers/infiniband/sw/siw/siw_verbs.c
index 869e02b69a012389d6d3533241012b1c1309e401..b18a677832e105ded578bd74d29694c45e55d031 100644 (file)
--- a/drivers/infiniband/sw/siw/siw_verbs.c
+++ b/drivers/infiniband/sw/siw/siw_verbs.c
@@ -604,7 +604,6 @@ out:
 int siw_destroy_qp(struct ib_qp *base_qp, struct ib_udata *udata)
 {
        struct siw_qp *qp = to_siw_qp(base_qp);
-       struct siw_base_qp *siw_base_qp = to_siw_base_qp(base_qp);
        struct siw_ucontext *uctx =
                rdma_udata_to_drv_context(udata, struct siw_ucontext,
                                          base_ucontext);
@@ -641,7 +640,6 @@ int siw_destroy_qp(struct ib_qp *base_qp, struct ib_udata *udata)
        qp->scq = qp->rcq = NULL;
 
        siw_qp_put(qp);
-       kfree(siw_base_qp);
 
        return 0;
 }