From patchwork Tue Jan 12 15:59:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 12013847 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 043ECC433DB for ; Tue, 12 Jan 2021 16:01:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AA028217BA for ; Tue, 12 Jan 2021 16:01:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392514AbhALQAr (ORCPT ); Tue, 12 Jan 2021 11:00:47 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:24619 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392447AbhALQAq (ORCPT ); Tue, 12 Jan 2021 11:00:46 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1610467160; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=RaGBKJaRxbpqH/rWxG6TwS7YqZeKFqoXKDauHdmaBc0=; b=f8TOSr/IbzBCZIrR58tpJo1ysbaExxpuq6O7MtCE2YHm56ayuymRwMefEkNdQqr+zVCOXM tfpcON9njCyhUffvkXEaM6mHoDDCnLndR+cfLA4cw671XueHKOTwieWp9pQ4pBL3JjONE/ rpvJM6Y8z+k6CFCutIb9trrpEC4rz50= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-282-OoP4vModPr-V1J7geuVelA-1; Tue, 12 Jan 2021 10:59:18 -0500 X-MC-Unique: OoP4vModPr-V1J7geuVelA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2DEB618C8C00; Tue, 12 Jan 2021 15:59:17 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-112-8.rdu2.redhat.com [10.10.112.8]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2AC7218B42; Tue, 12 Jan 2021 15:59:16 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH net] rxrpc: Call state should be read with READ_ONCE() under some circumstances From: David Howells To: netdev@vger.kernel.org Cc: Baptiste Lepers , linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org, dhowells@redhat.com Date: Tue, 12 Jan 2021 15:59:15 +0000 Message-ID: <161046715522.2450566.488819910256264150.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.23 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Baptiste Lepers The call state may be changed at any time by the data-ready routine in response to received packets, so if the call state is to be read and acted upon several times in a function, READ_ONCE() must be used unless the call state lock is held. As it happens, we used READ_ONCE() to read the state a few lines above the unmarked read in rxrpc_input_data(), so use that value rather than re-reading it. Signed-off-by: Baptiste Lepers Signed-off-by: David Howells --- net/rxrpc/input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c index 667c44aa5a63..dc201363f2c4 100644 --- a/net/rxrpc/input.c +++ b/net/rxrpc/input.c @@ -430,7 +430,7 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb) return; } - if (call->state == RXRPC_CALL_SERVER_RECV_REQUEST) { + if (state == RXRPC_CALL_SERVER_RECV_REQUEST) { unsigned long timo = READ_ONCE(call->next_req_timo); unsigned long now, expect_req_by;