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 7EDB3CCA487 for ; Tue, 7 Jun 2022 19:11:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355141AbiFGTLM (ORCPT ); Tue, 7 Jun 2022 15:11:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35200 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351460AbiFGSXe (ORCPT ); Tue, 7 Jun 2022 14:23:34 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 03F5AC9ED5; Tue, 7 Jun 2022 10:54:21 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 4D95461846; Tue, 7 Jun 2022 17:54:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5B820C385A5; Tue, 7 Jun 2022 17:54:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1654624459; bh=y1kr5Heb/C7va/aR2tlmANm0HN4/JLfZxF885GOasXQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gSD1qpS7jJBvXE4e0fFl7mIGYSX5iXXLT3wJgHfZz75N3VmLJkzKsNP9oMTCgmsw/ M3Db/tmZ7Z/5MaTpv53IJP5cmm/cQVMv6Rb9AbD+JIu+VuG64B3Y7P8Hy5V5Xmmo64 8jgLiUME68ko0cB+eifvmxlzi3dFDbzBeK/ebTUE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , Neil Horman , Vlad Yasevich , Marcelo Ricardo Leitner , "David S. Miller" , Sasha Levin Subject: [PATCH 5.15 334/667] sctp: read sk->sk_bound_dev_if once in sctp_rcv() Date: Tue, 7 Jun 2022 18:59:59 +0200 Message-Id: <20220607164944.784390057@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220607164934.766888869@linuxfoundation.org> References: <20220607164934.766888869@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: linux-kernel@vger.kernel.org From: Eric Dumazet [ Upstream commit a20ea298071f46effa3aaf965bf9bb34c901db3f ] sctp_rcv() reads sk->sk_bound_dev_if twice while the socket is not locked. Another cpu could change this field under us. Fixes: 0fd9a65a76e8 ("[SCTP] Support SO_BINDTODEVICE socket option on incoming packets.") Signed-off-by: Eric Dumazet Cc: Neil Horman Cc: Vlad Yasevich Cc: Marcelo Ricardo Leitner Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/sctp/input.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/sctp/input.c b/net/sctp/input.c index 1f1786021d9c..d16b3885dccc 100644 --- a/net/sctp/input.c +++ b/net/sctp/input.c @@ -92,6 +92,7 @@ int sctp_rcv(struct sk_buff *skb) struct sctp_chunk *chunk; union sctp_addr src; union sctp_addr dest; + int bound_dev_if; int family; struct sctp_af *af; struct net *net = dev_net(skb->dev); @@ -169,7 +170,8 @@ int sctp_rcv(struct sk_buff *skb) * If a frame arrives on an interface and the receiving socket is * bound to another interface, via SO_BINDTODEVICE, treat it as OOTB */ - if (sk->sk_bound_dev_if && (sk->sk_bound_dev_if != af->skb_iif(skb))) { + bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); + if (bound_dev_if && (bound_dev_if != af->skb_iif(skb))) { if (transport) { sctp_transport_put(transport); asoc = NULL; -- 2.35.1