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 1BB85ECAAD5 for ; Tue, 6 Sep 2022 13:55:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239487AbiIFNza (ORCPT ); Tue, 6 Sep 2022 09:55:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41120 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238805AbiIFNxb (ORCPT ); Tue, 6 Sep 2022 09:53:31 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 89684804B7; Tue, 6 Sep 2022 06:40:48 -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 sin.source.kernel.org (Postfix) with ESMTPS id 01F4ECE177D; Tue, 6 Sep 2022 13:40:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4F614C433D6; Tue, 6 Sep 2022 13:40:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1662471633; bh=CRt/nAFidu2/Fa+kSY83hNUBSE8UekJvMXGOpiPP4Fo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Zb8sqikqxkWaTRGEjUxkgMO5p7nFcWJk2Eult5obXZ3aL1NR3fiTYZMo5CIuSW+50 J5bfcyspxVkeLfwss/Xw3qa8D5jo+L4BrtHGgylPwUKKwzyk0yPCKs0/fNFqkDQ6q+ LW+DbG7XURvke60GXNqGEPevj1p/fPdlVIN9rZqU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, kernel test robot , Heng Qi , Nicolas Dichtel , David Ahern , Jakub Kicinski Subject: [PATCH 5.15 092/107] ip: fix triggering of icmp redirect Date: Tue, 6 Sep 2022 15:31:13 +0200 Message-Id: <20220906132825.720445776@linuxfoundation.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220906132821.713989422@linuxfoundation.org> References: <20220906132821.713989422@linuxfoundation.org> User-Agent: quilt/0.67 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: Nicolas Dichtel commit eb55dc09b5dd040232d5de32812cc83001a23da6 upstream. __mkroute_input() uses fib_validate_source() to trigger an icmp redirect. My understanding is that fib_validate_source() is used to know if the src address and the gateway address are on the same link. For that, fib_validate_source() returns 1 (same link) or 0 (not the same network). __mkroute_input() is the only user of these positive values, all other callers only look if the returned value is negative. Since the below patch, fib_validate_source() didn't return anymore 1 when both addresses are on the same network, because the route lookup returns RT_SCOPE_LINK instead of RT_SCOPE_HOST. But this is, in fact, right. Let's adapat the test to return 1 again when both addresses are on the same link. CC: stable@vger.kernel.org Fixes: 747c14307214 ("ip: fix dflt addr selection for connected nexthop") Reported-by: kernel test robot Reported-by: Heng Qi Signed-off-by: Nicolas Dichtel Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20220829100121.3821-1-nicolas.dichtel@6wind.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/ipv4/fib_frontend.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -389,7 +389,7 @@ static int __fib_validate_source(struct dev_match = dev_match || (res.type == RTN_LOCAL && dev == net->loopback_dev); if (dev_match) { - ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST; + ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_LINK; return ret; } if (no_addr) @@ -401,7 +401,7 @@ static int __fib_validate_source(struct ret = 0; if (fib_lookup(net, &fl4, &res, FIB_LOOKUP_IGNORE_LINKSTATE) == 0) { if (res.type == RTN_UNICAST) - ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_HOST; + ret = FIB_RES_NHC(res)->nhc_scope >= RT_SCOPE_LINK; } return ret;