From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 52CF6C433EF for ; Tue, 12 Apr 2022 07:08:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245289AbiDLHKW (ORCPT ); Tue, 12 Apr 2022 03:10:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46850 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353098AbiDLHHF (ORCPT ); Tue, 12 Apr 2022 03:07:05 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B2393624B; Mon, 11 Apr 2022 23:49:17 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id CE2DCB81B43; Tue, 12 Apr 2022 06:49:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2CA17C385A1; Tue, 12 Apr 2022 06:49:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649746154; bh=r8a9lHuAGZPUTvvW+D5b/UG4FvvagGtzxKifdNP/HL8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EVKnEVFANbsDiEgTNSAlGXpeUPIItZuPD/o+e0tT+lyJUZpL7FVqcThipJf7QM7P2 Aa4hMs403dEySHIa3bp8+gxw+IIhraDH+guUjDh35iWevY/mz1oPtL7AnQWheOfQt3 psjJyMSlSwUPBsUCmJndUqwgUa4jWxakMjR7Q014= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Niels Dossche , Dennis Dalessandro , Jason Gunthorpe , Sasha Levin Subject: [PATCH 5.15 178/277] IB/rdmavt: add lock to call to rvt_error_qp to prevent a race condition Date: Tue, 12 Apr 2022 08:29:41 +0200 Message-Id: <20220412062947.187970585@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220412062942.022903016@linuxfoundation.org> References: <20220412062942.022903016@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Niels Dossche [ Upstream commit 4d809f69695d4e7d1378b3a072fa9aef23123018 ] The documentation of the function rvt_error_qp says both r_lock and s_lock need to be held when calling that function. It also asserts using lockdep that both of those locks are held. However, the commit I referenced in Fixes accidentally makes the call to rvt_error_qp in rvt_ruc_loopback no longer covered by r_lock. This results in the lockdep assertion failing and also possibly in a race condition. Fixes: d757c60eca9b ("IB/rdmavt: Fix concurrency panics in QP post_send and modify to error") Link: https://lore.kernel.org/r/20220228165330.41546-1-dossche.niels@gmail.com Signed-off-by: Niels Dossche Acked-by: Dennis Dalessandro Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin --- drivers/infiniband/sw/rdmavt/qp.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/sw/rdmavt/qp.c b/drivers/infiniband/sw/rdmavt/qp.c index ae50b56e8913..8ef112f883a7 100644 --- a/drivers/infiniband/sw/rdmavt/qp.c +++ b/drivers/infiniband/sw/rdmavt/qp.c @@ -3190,7 +3190,11 @@ void rvt_ruc_loopback(struct rvt_qp *sqp) spin_lock_irqsave(&sqp->s_lock, flags); rvt_send_complete(sqp, wqe, send_status); if (sqp->ibqp.qp_type == IB_QPT_RC) { - int lastwqe = rvt_error_qp(sqp, IB_WC_WR_FLUSH_ERR); + int lastwqe; + + spin_lock(&sqp->r_lock); + lastwqe = rvt_error_qp(sqp, IB_WC_WR_FLUSH_ERR); + spin_unlock(&sqp->r_lock); sqp->s_flags &= ~RVT_S_BUSY; spin_unlock_irqrestore(&sqp->s_lock, flags); -- 2.35.1