Commit a3c27880 authored Sep 20, 2022 by Bernard Metzler Committed by Leon Romanovsky Sep 20, 2022

RDMA/siw: Fix QP destroy to wait for all references dropped.



Delay QP destroy completion until all siw references to QP are
dropped. The calling RDMA core will free QP structure after
successful return from siw_qp_destroy() call, so siw must not
hold any remaining reference to the QP upon return.
A use-after-free was encountered in xfstest generic/460, while
testing NFSoRDMA. Here, after a TCP connection drop by peer,
the triggered siw_cm_work_handler got delayed until after
QP destroy call, referencing a QP which has already freed.

Fixes: 303ae1cd ("rdma/siw: application interface")
Reported-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Bernard Metzler <bmt@zurich.ibm.com>
Link: https://lore.kernel.org/r/20220920082503.224189-1-bmt@zurich.ibm.com


Signed-off-by: Leon Romanovsky <leon@kernel.org>

parent 75420985

drivers/infiniband/sw/siw/siw.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -418,6 +418,7 @@ struct siw_qp {
		struct ib_qp base_qp;
		struct siw_device *sdev;
		struct kref ref;
		struct completion qp_free;
		struct list_head devq;
		int tx_cpu;
		struct siw_qp_attrs attrs;

drivers/infiniband/sw/siw/siw_qp.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1342,6 +1342,6 @@ void siw_free_qp(struct kref *ref)
		vfree(qp->orq);

		siw_put_tx_cpu(qp->tx_cpu);

		complete(&qp->qp_free);
		atomic_dec(&sdev->num_qp);
		}

drivers/infiniband/sw/siw/siw_verbs.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -480,6 +480,8 @@ int siw_create_qp(struct ib_qp ibqp, struct ib_qp_init_attr attrs,
		list_add_tail(&qp->devq, &sdev->qp_list);
		spin_unlock_irqrestore(&sdev->lock, flags);

		init_completion(&qp->qp_free);

		return 0;

		err_out_xa:
		@@ -624,6 +626,7 @@ int siw_destroy_qp(struct ib_qp base_qp, struct ib_udata udata)
		qp->scq = qp->rcq = NULL;

		siw_qp_put(qp);
		wait_for_completion(&qp->qp_free);

		return 0;
		}