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 DE7B930F542; Tue, 2 Sep 2025 13:39:47 +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=1756820388; cv=none; b=REHNkrD1+a6eRq3dNaC5IWE7sJm5XmT48RIBoAs7aMJUDUda9MQvHXeLX2ifgyXteRGhYebLdwVMr2NEj2jqPGpYYLqE9nyj62BIj9X1YAZDw7n5n8uRQvcwv8PEyGfgwGyn83q0e7de+uuQ0kCq7biiJLecuUuA/WYENyvipTs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756820388; c=relaxed/simple; bh=gCk56bk+0dLHEqff9fLoMqRV7vuSqsyvQsi5pMc1sbQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=M+wLdgbCacPV96LjxRegj6ajOtqzWEyWYAV55BD9nbxUVTJQhLfcpU9XI1g8sA6rreG5H0jhTSndvvoyNQDR0Y653QcsgBjzlSBOCYiBa8kbagKHcO/J/LALaIWJKbcBwwnXoGcO+9ucLr0GAYYRW/hnn1xXmp19QMxkOFo4lhI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=1/w0U/Ic; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="1/w0U/Ic" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5621CC4CEED; Tue, 2 Sep 2025 13:39:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1756820387; bh=gCk56bk+0dLHEqff9fLoMqRV7vuSqsyvQsi5pMc1sbQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1/w0U/IcP+7qYmgyiv4DjGVU4S+9DeGRa+uUUcdFOt0bKicDqKfCtc7umlfq2Lm2d yaBbK3X/gwN/ryxs7q++g/8uKkN257NqOyRSOahYEyd6grslHu2dzjSk8To5Og/iqB /8JB5uuU1qWyaUNFVtut6CP74Qw0oQWRvyhdFaQE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Brett A C Sheffield , Oscar Maes , David Ahern , Paolo Abeni , Sasha Levin Subject: [PATCH 6.1 13/50] net: ipv4: fix regression in local-broadcast routes Date: Tue, 2 Sep 2025 15:21:04 +0200 Message-ID: <20250902131931.044763619@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20250902131930.509077918@linuxfoundation.org> References: <20250902131930.509077918@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Oscar Maes [ Upstream commit 5189446ba995556eaa3755a6e875bc06675b88bd ] 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. This preserves the intended changes for directed-broadcast packets. Cc: stable@vger.kernel.org Fixes: 9e30ecf23b1b ("net: ipv4: fix incorrect MTU in broadcast routes") Reported-by: Brett A C Sheffield Closes: https://lore.kernel.org/regressions/20250822165231.4353-4-bacs@librecast.net Signed-off-by: Oscar Maes Reviewed-by: David Ahern Link: https://patch.msgid.link/20250827062322.4807-1-oscmaes92@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/ipv4/route.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index c57a1cee98e2c..395bc567b15d3 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -2549,12 +2549,16 @@ 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)) + } else if (ipv4_is_zeronet(fl4->daddr)) { return ERR_PTR(-EINVAL); + } if (dev_out->flags & IFF_LOOPBACK) flags |= RTCF_LOCAL; -- 2.50.1