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 13352C35294 for ; Wed, 9 Mar 2022 16:50:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237977AbiCIQu3 (ORCPT ); Wed, 9 Mar 2022 11:50:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59852 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234410AbiCIQcq (ORCPT ); Wed, 9 Mar 2022 11:32:46 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ACCA01AAFFA; Wed, 9 Mar 2022 08:28:14 -0800 (PST) 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 6FAEBB82254; Wed, 9 Mar 2022 16:28:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 33625C340F5; Wed, 9 Mar 2022 16:27:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1646843283; bh=ORgOXrbErGzG4bsiU02n8K34kQWixB1gzAnSuiyDSKY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=am36o434kzymKcYxH5Bw8aHKBJ7ICH8gE8r4hb1tRzgu2yt7lVpZigThN5gshqrmA 24L8ngu04yAPRPMNUwPJ4R3hM4ujaqr3WKwiU6MgjE99vewQdxf+amd4spKFMYpw8/ B+YtzIfieHe9YXXP92zyagRYgtzdskUeqUSWT8aTjgyFfnZTlPAVr7O+1borBMLllE 1VTkM3hGc4vnS55KwJCs6bf7yU7gJfKv3XkfnCOmfQ1Ni9lhaBjxLqgBnSAVIpDoSM dp0bwt+OjZ/CjbG4VrPp9HCa7emQyMlsvI2nHvVG/XV+BqUhxPd8f+2Fez0Bg9vgpu jdKAY5W13TdDw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Niels Dossche , Martin Habets , "David S . Miller" , Sasha Levin , ecree.xilinx@gmail.com, kuba@kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 09/11] sfc: extend the locking on mcdi->seqno Date: Wed, 9 Mar 2022 11:27:14 -0500 Message-Id: <20220309162716.137399-9-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220309162716.137399-1-sashal@kernel.org> References: <20220309162716.137399-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Niels Dossche [ Upstream commit f1fb205efb0ccca55626fd4ef38570dd16b44719 ] seqno could be read as a stale value outside of the lock. The lock is already acquired to protect the modification of seqno against a possible race condition. Place the reading of this value also inside this locking to protect it against a possible race condition. Signed-off-by: Niels Dossche Acked-by: Martin Habets Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/ethernet/sfc/mcdi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c index 241520943ada..221798499e24 100644 --- a/drivers/net/ethernet/sfc/mcdi.c +++ b/drivers/net/ethernet/sfc/mcdi.c @@ -162,9 +162,9 @@ static void efx_mcdi_send_request(struct efx_nic *efx, unsigned cmd, /* Serialise with efx_mcdi_ev_cpl() and efx_mcdi_ev_death() */ spin_lock_bh(&mcdi->iface_lock); ++mcdi->seqno; + seqno = mcdi->seqno & SEQ_MASK; spin_unlock_bh(&mcdi->iface_lock); - seqno = mcdi->seqno & SEQ_MASK; xflags = 0; if (mcdi->mode == MCDI_MODE_EVENTS) xflags |= MCDI_HEADER_XFLAGS_EVREQ; -- 2.34.1