From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0317C2C3261; Mon, 25 Aug 2025 22:56:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756162592; cv=none; b=l3UXBOWKsh5iCNUpGi38aXQ1kDQxcum7AmwF79So0nR1mTYWfuvzQa6irb3Yz8ZxABM/fjrd7g5/fe8/RQPx9B/QP+fICOlrk2vD99fg7ijova+nFHsRZ0ahJSBuvdMu8axeWp6pVcUCkGDAAd2YlXt2tGSJO4GZmP4hYvUBbDU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756162592; c=relaxed/simple; bh=1EwS02lvQFkf1B1/XBnY3ItiLLai366NbFmVSIdJjyY=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=M5+vPN9a/N+/s4/keLYbFIKgYwk8etki7j50wSTHNgttFFw98sb9/NBXVbpwYucSljDFytBjbWFNxWc6MF8IOOcOohbo51ofq3QDJdJ3nEjKlA1qxgTlaxz8NRCLHobxNG+wgI44B/ica/JOTlvbubk4tktRmkRQcxlkij3sZ3s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=bZwsOn/3; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="bZwsOn/3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4C326C4CEED; Mon, 25 Aug 2025 22:56:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756162591; bh=1EwS02lvQFkf1B1/XBnY3ItiLLai366NbFmVSIdJjyY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=bZwsOn/3Pj9RnVq2HgNIxcs4N8XRlIVgl8jxLTCxR2SJd7TlVMiObIm7soDAO6SLL jqh5hlRJM06cuhDmMs6LtnKsjCu5aZNqzW9TnUfATG8WSYro4hBeWPj+WJWJrGl0G4 DljoPOYJjwpkHPWelKoPt1+HmYyulIVqtXIORzjzKt+nq1ffOkMeuOPSW7tBdg8pvD dl/yQzHN65i3hlr8L+gjMcQ38rdeRlzIeBqAsuwxVG6t8hEy/rYC9zV+QK70bISF9e Y/tSBtxFHS5nF9cU2D7QPNvmyznDhd/H0lFaUcLsmq0YeT1rPRoFEMIdIq/f1OIDS+ nZb5fyuAbOHLA== Date: Mon, 25 Aug 2025 15:56:30 -0700 From: Jakub Kicinski To: Oscar Maes Cc: bacs@librecast.net, brett@librecast.net, davem@davemloft.net, dsahern@kernel.org, netdev@vger.kernel.org, regressions@lists.linux.dev, stable@vger.kernel.org Subject: Re: [PATCH net 1/2] net: ipv4: fix regression in local-broadcast routes Message-ID: <20250825155630.5848c357@kernel.org> In-Reply-To: <20250825060918.4799-1-oscmaes92@gmail.com> References: <20250825060229-oscmaes92@gmail.com> <20250825060918.4799-1-oscmaes92@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Mon, 25 Aug 2025 08:09:17 +0200 Oscar Maes wrote: > Commit 9e30ecf23b1b ("net: ipv4: fix incorrect MTU in broadcast routes") > introduced a regression where local-broadcast packets would have their > gateway set in __mkroute_output, which was caused by fi = NULL being > removed. > > Fix this by resetting the fib_info for local-broadcast packets. Meaning that 9e30ecf23b1b would still change behavior for the subnet broadcast address? > diff --git a/net/ipv4/route.c b/net/ipv4/route.c > index f639a2ae881a..98d237e3ec04 100644 > --- a/net/ipv4/route.c > +++ b/net/ipv4/route.c > @@ -2575,9 +2575,12 @@ static struct rtable *__mkroute_output(const struct fib_result *res, > !netif_is_l3_master(dev_out)) > return ERR_PTR(-EINVAL); > > - if (ipv4_is_lbcast(fl4->daddr)) > + if (ipv4_is_lbcast(fl4->daddr)) { > type = RTN_BROADCAST; > - else if (ipv4_is_multicast(fl4->daddr)) > + > + /* reset fi to prevent gateway resolution */ > + fi = NULL; > + } else if (ipv4_is_multicast(fl4->daddr)) > type = RTN_MULTICAST; > else if (ipv4_is_zeronet(fl4->daddr)) > return ERR_PTR(-EINVAL); nit: please add curly braces around all branches of this if / else if / else ladder, per kernel coding style guide. -- pw-bot: cr