From: Jack Morgenstein Date: Thu, 29 Dec 2016 16:37:09 +0000 (+0200) Subject: net/mlx4_core: Use-after-free causes a resource leak in flow-steering detach X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=3b01fe7f91c8e4f9afc4fae3c5af72c14958d2d8;p=linux-beck.git net/mlx4_core: Use-after-free causes a resource leak in flow-steering detach mlx4_QP_FLOW_STEERING_DETACH_wrapper first removes the steering rule (which results in freeing the rule structure), and then references a field in this struct (the qp number) when releasing the busy-status on the rule's qp. Since this memory was freed, it could reallocated and changed. Therefore, the qp number in the struct may be incorrect, so that we are releasing the incorrect qp. This leaves the rule's qp in the busy state (and could possibly release an incorrect qp as well). Fix this by saving the qp number in a local variable, for use after removing the steering rule. Fixes: 2c473ae7e582 ("net/mlx4_core: Disallow releasing VF QPs which have steering rules") Signed-off-by: Jack Morgenstein Signed-off-by: Tariq Toukan Signed-off-by: David S. Miller --- diff --git a/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c b/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c index c548beaaf910..4b3e139e9c82 100644 --- a/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c +++ b/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c @@ -4473,6 +4473,7 @@ int mlx4_QP_FLOW_STEERING_DETACH_wrapper(struct mlx4_dev *dev, int slave, struct res_qp *rqp; struct res_fs_rule *rrule; u64 mirr_reg_id; + int qpn; if (dev->caps.steering_mode != MLX4_STEERING_MODE_DEVICE_MANAGED) @@ -4489,10 +4490,11 @@ int mlx4_QP_FLOW_STEERING_DETACH_wrapper(struct mlx4_dev *dev, int slave, } mirr_reg_id = rrule->mirr_rule_id; kfree(rrule->mirr_mbox); + qpn = rrule->qpn; /* Release the rule form busy state before removal */ put_res(dev, slave, vhcr->in_param, RES_FS_RULE); - err = get_res(dev, slave, rrule->qpn, RES_QP, &rqp); + err = get_res(dev, slave, qpn, RES_QP, &rqp); if (err) return err; @@ -4517,7 +4519,7 @@ int mlx4_QP_FLOW_STEERING_DETACH_wrapper(struct mlx4_dev *dev, int slave, if (!err) atomic_dec(&rqp->ref_count); out: - put_res(dev, slave, rrule->qpn, RES_QP); + put_res(dev, slave, qpn, RES_QP); return err; }