From patchwork Fri Aug 31 14:15:56 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steve Wise X-Patchwork-Id: 10584117 X-Patchwork-Delegate: jgg@ziepe.ca Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5814913AC for ; Fri, 31 Aug 2018 15:49:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 485542C1DC for ; Fri, 31 Aug 2018 15:49:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3C1392C1F8; Fri, 31 Aug 2018 15:49:25 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DC1AB2C1DC for ; Fri, 31 Aug 2018 15:49:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729177AbeHaT53 (ORCPT ); Fri, 31 Aug 2018 15:57:29 -0400 Received: from 72-48-214-68.dyn.grandenetworks.net ([72.48.214.68]:47356 "EHLO smtp.opengridcomputing.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728222AbeHaT52 (ORCPT ); Fri, 31 Aug 2018 15:57:28 -0400 Received: by smtp.opengridcomputing.com (Postfix, from userid 503) id B79EB22788; Fri, 31 Aug 2018 10:49:21 -0500 (CDT) Message-Id: <71ab90d6d2639d812587bf7afa280e2f27d21b1e.1535730440.git.swise@opengridcomputing.com> From: Steve Wise Date: Fri, 31 Aug 2018 07:15:56 -0700 Subject: [PATCH] iw_cxgb4: only allow 1 flush on user qps To: linux-rdma@vger.kernel.org Cc: jgg@ziepe.ca, dledford@redhat.com Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Once the qp has been flushed, it cannot be flushed again. The user qp flush logic wasn't enforcing it however. The bug can cause touch-after-free crashes like: Unable to handle kernel paging request for data at address 0x000001ec Faulting instruction address: 0xc008000016069100 Oops: Kernel access of bad area, sig: 11 [#1] ... NIP [c008000016069100] flush_qp+0x80/0x480 [iw_cxgb4] LR [c00800001606cd6c] c4iw_modify_qp+0x71c/0x11d0 [iw_cxgb4] Call Trace: [c00800001606cd6c] c4iw_modify_qp+0x71c/0x11d0 [iw_cxgb4] [c00800001606e868] c4iw_ib_modify_qp+0x118/0x200 [iw_cxgb4] [c0080000119eae80] ib_security_modify_qp+0xd0/0x3d0 [ib_core] [c0080000119c4e24] ib_modify_qp+0xc4/0x2c0 [ib_core] [c008000011df0284] iwcm_modify_qp_err+0x44/0x70 [iw_cm] [c008000011df0fec] destroy_cm_id+0xcc/0x370 [iw_cm] [c008000011ed4358] rdma_destroy_id+0x3c8/0x520 [rdma_cm] [c0080000134b0540] ucma_close+0x90/0x1b0 [rdma_ucm] [c000000000444da4] __fput+0xe4/0x2f0 So fix flush_qp() to only flush the wq once. Cc: stable@vger.kernel.org Signed-off-by: Steve Wise --- drivers/infiniband/hw/cxgb4/qp.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/infiniband/hw/cxgb4/qp.c b/drivers/infiniband/hw/cxgb4/qp.c index b3203afa3b1d..347fe18b1a41 100644 --- a/drivers/infiniband/hw/cxgb4/qp.c +++ b/drivers/infiniband/hw/cxgb4/qp.c @@ -1685,6 +1685,12 @@ static void flush_qp(struct c4iw_qp *qhp) schp = to_c4iw_cq(qhp->ibqp.send_cq); if (qhp->ibqp.uobject) { + + /* for user qps, qhp->wq.flushed is protected by qhp->mutex */ + if (qhp->wq.flushed) + return; + + qhp->wq.flushed = 1; t4_set_wq_in_error(&qhp->wq, 0); t4_set_cq_in_error(&rchp->cq); spin_lock_irqsave(&rchp->comp_handler_lock, flag);