[gentoo-commits] proj/linux-patches:6.16 commit in: /

["Arisu Tachibana" <alicef@gentoo.org>]

commit:     f9fb3f8988f07024269de6c05cd3e56481ab028c
Author:     Arisu Tachibana <alicef <AT> gentoo <DOT> org>
AuthorDate: Thu Aug 28 15:08:20 2025 +0000
Commit:     Arisu Tachibana <alicef <AT> gentoo <DOT> org>
CommitDate: Thu Aug 28 15:08:20 2025 +0000
URL:        https://gitweb.gentoo.org/proj/linux-patches.git/commit/?id=f9fb3f89

Add net: ipv4: fix regression in local-broadcast routes

Signed-off-by: Arisu Tachibana <alicef <AT> gentoo.org>

 0000_README                                        |   4 +
 ..._fix_regression_in_local-broadcast_routes.patch | 134 +++++++++++++++++++++
 2 files changed, 138 insertions(+)

diff --git a/0000_README b/0000_README
index 0bac5f02..7698b47d 100644
--- a/0000_README
+++ b/0000_README
@@ -71,6 +71,10 @@ Patch:  2000_BT-Check-key-sizes-only-if-Secure-Simple-Pairing-enabled.patch
 From:   https://lore.kernel.org/linux-bluetooth/20190522070540.48895-1-marcel@holtmann.org/raw
 Desc:   Bluetooth: Check key sizes only when Secure Simple Pairing is enabled. See bug #686758
 
+Patch:  2010_ipv4_fix_regression_in_local-broadcast_routes.patch
+From:   https://lore.kernel.org/regressions/20250826121750.8451-1-oscmaes92@gmail.com/
+Desc:   net: ipv4: fix regression in local-broadcast routes
+
 Patch:  2901_permit-menuconfig-sorting.patch
 From:   https://lore.kernel.org/
 Desc:   menuconfig: Allow sorting the entries alphabetically

diff --git a/2010_ipv4_fix_regression_in_local-broadcast_routes.patch b/2010_ipv4_fix_regression_in_local-broadcast_routes.patch
new file mode 100644
index 00000000..a306132d
--- /dev/null
+++ b/2010_ipv4_fix_regression_in_local-broadcast_routes.patch
@@ -0,0 +1,134 @@
+From mboxrd@z Thu Jan  1 00:00:00 1970
+Received: from mail-wm1-f48.google.com (mail-wm1-f48.google.com [209.85.128.48])
+	(using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits))
+	(No client certificate requested)
+	by smtp.subspace.kernel.org (Postfix) with ESMTPS id 35E81393DF2
+	for <regressions@lists.linux.dev>; Tue, 26 Aug 2025 12:18:24 +0000 (UTC)
+Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.48
+ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;
+	t=1756210706; cv=none; b=Da/rRcCPW+gdgl9sh1AJU0E8vP05G0xfCEUnpWuqnQjaf8/mvVPUhzba4pXCTtFhHNsTTT3iEOPPiPqCzdNwRexxsZIkyL6JGG+hXkV8cn+i7XctZ961TmWYP8ACY74i8MLs7Iud+2gt8y4VrLoMeHXcE7ripzyOxa8THiVuFTc=
+ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org;
+	s=arc-20240116; t=1756210706; c=relaxed/simple;
+	bh=WNRFfbyB1JScy1/30FZa+Ntq9RVZSUi/ijHlpcIjNBs=;
+	h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References:
+	 MIME-Version; b=Y3iH3AFJjiR147yq3M5X/KlRR6baEAus+ZHb4N2PZZKa0T3Ln2c2/SnZLXQgRCa8rdr3MCFoXaoDuRUcx8k744Dh1j64HY9sRnYjM01rc0Kh+iaf3nZ0jYkC+zOL+8Wv5eWgNbDX5Qg+WzwUQMQhrC5xEQNjNorKTxd+SRFGpao=
+ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=dvEwPzW3; arc=none smtp.client-ip=209.85.128.48
+Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com
+Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com
+Authentication-Results: smtp.subspace.kernel.org;
+	dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="dvEwPzW3"
+Received: by mail-wm1-f48.google.com with SMTP id 5b1f17b1804b1-45a1b004954so43862245e9.0
+        for <regressions@lists.linux.dev>; Tue, 26 Aug 2025 05:18:23 -0700 (PDT)
+DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
+        d=gmail.com; s=20230601; t=1756210702; x=1756815502; darn=lists.linux.dev;
+        h=content-transfer-encoding:mime-version:references:in-reply-to
+         :message-id:date:subject:cc:to:from:from:to:cc:subject:date
+         :message-id:reply-to;
+        bh=LChTYlNX7jpHHdvqfK7E+ehTE+2KqMA/oVeIigfrSAA=;
+        b=dvEwPzW3bP5r/IJF4+nyqmSsoFRE2/TxvBct7S3hXKOLTfxpExbkGfpZTxb/wRhBAJ
+         wQL8iEOoH47boqy/i72LQhH6bNLS72yU2FMpqZNVENRJqtwB6lq8PJlRvDn7gEVW4awK
+         8Phof2i45jLRu1288bEfZkYpSVK0hclcCXgP/5f7t0zNSdutKc/aOXCyLeoIeciLR4Zx
+         JmtIedPpVahUnw0oCgxmQbOkHd3yf1xoxAiEblYfya59tRXPty3gfMnh2Ox4gTYn29NF
+         kp+PqMg4GxVf0j4TZMuCnBqnjtYFkfDpGyqNr4HBBV4PzdZjjbuJ8bPNOVUNOzk14j+4
+         JE9Q==
+X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
+        d=1e100.net; s=20230601; t=1756210702; x=1756815502;
+        h=content-transfer-encoding:mime-version:references:in-reply-to
+         :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc
+         :subject:date:message-id:reply-to;
+        bh=LChTYlNX7jpHHdvqfK7E+ehTE+2KqMA/oVeIigfrSAA=;
+        b=XlKRIeF/DtRxj+OA67VSgyB25oK9Z0gak5vT5pjoH+XFlP+Y6y9GSx70oRvvIgIZE0
+         apTakbKssvoFmeCLmAFQRStZfubuWoor6Ond1N/6K7j7VBU11eysPUkeo6jQSTzdSQMt
+         v9Jq11Lnaii0ms5s6kIaWWPR9lGAWFb++ZJNYkXt59iXnhEVlVW4dFssD6VR/VJnyX+e
+         A+eGOVoa1k3c4ae23Wmq55GQR1iKbviKO28+BXatjKRWcFjaTgedk1WATZrrwcRYdD2E
+         a3r6R5iTOkMNX/TOJ4v2X7s69ndC+qxxJQ0yLTAsmfV1EDGUp3kwwkdIVl3UDqUhHszh
+         N0+w==
+X-Forwarded-Encrypted: i=1; AJvYcCX+aV0s2nW7qE7ZH57rmDl4GNnOxwFmQdMvPxxvM100/HNXQPAUrKLUeYBdO5rTpnftaJQ4J3zRSge7XA==@lists.linux.dev
+X-Gm-Message-State: AOJu0Yy9j79mStVe7fYpUjVZm00DYURS6tKQYofu48lxIG03z+fJEMUq
+	NKggf5H7k0btf9k9VXff6yWYNoL6JnO/uWjuPcDWrTtpRme13iQ8weyk
+X-Gm-Gg: ASbGncv/CVsSHrFQyxd//IAOzxZbvxje250ZYi2TUZi9g/Gf4x/86XgM4MjXoZFeBZB
+	4c00kmZrQIKWk4ToI+ySCSydYzZQbrw+nGnrad6FqeWQESk5tqOBYnIYKTUT+rseRkG5dukKJdE
+	lNeFu0sfmmoAnvNyKtLNqG9VwFQtqSwODKIKH+CZ92mMBuWe4ePVv4JQpz/fUhIRN+eZBdfDwUZ
+	eWZScFkZRFJo2SrVq9Ku3CIOA8hD0ktkkBDaFj57r+4YoToeLSvbCzzZrcFGoj2E1zqyTSlUhbf
+	SsKS4HgBDjkhx2k41IZAVyT+pE/GfU2BgS6BmY/VUxh72VrmHWCvbCnGX1TsHixJSwCGJiilLTg
+	KuDu6j0RQCZjyzUt7t8/H5A==
+X-Google-Smtp-Source: AGHT+IGDspJcry+lZbYtZeVg4+4kmcTBPmZuyilfg0+W2o8HlDsbRsJZkF4781x4cl6MBUZul/po1A==
+X-Received: by 2002:a05:600c:3b2a:b0:453:2066:4a26 with SMTP id 5b1f17b1804b1-45b5179f3d1mr194717105e9.16.1756210702258;
+        Tue, 26 Aug 2025 05:18:22 -0700 (PDT)
+Received: from oscar-xps.. ([45.128.133.231])
+        by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-45b5758a0bfsm149513675e9.20.2025.08.26.05.18.18
+        (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);
+        Tue, 26 Aug 2025 05:18:21 -0700 (PDT)
+From: Oscar Maes <oscmaes92@gmail.com>
+To: bacs@librecast.net,
+	brett@librecast.net,
+	kuba@kernel.org
+Cc: davem@davemloft.net,
+	dsahern@kernel.org,
+	netdev@vger.kernel.org,
+	regressions@lists.linux.dev,
+	stable@vger.kernel.org,
+	Oscar Maes <oscmaes92@gmail.com>
+Subject: [PATCH net v2 1/2] net: ipv4: fix regression in local-broadcast routes
+Date: Tue, 26 Aug 2025 14:17:49 +0200
+Message-Id: <20250826121750.8451-1-oscmaes92@gmail.com>
+X-Mailer: git-send-email 2.39.5
+In-Reply-To: <20250826121126-oscmaes92@gmail.com>
+References: <20250826121126-oscmaes92@gmail.com>
+Precedence: bulk
+X-Mailing-List: regressions@lists.linux.dev
+List-Id: <regressions.lists.linux.dev>
+List-Subscribe: <mailto:regressions+subscribe@lists.linux.dev>
+List-Unsubscribe: <mailto:regressions+unsubscribe@lists.linux.dev>
+MIME-Version: 1.0
+Content-Transfer-Encoding: 8bit
+
+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 <bacs@librecast.net>
+Closes: https://lore.kernel.org/regressions/20250822165231.4353-4-bacs@librecast.net
+Signed-off-by: Oscar Maes <oscmaes92@gmail.com>
+---
+
+Thanks to Brett Sheffield for finding the regression and writing
+the initial fix!
+---
+ 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 1f212b2ce4c6..24c898b7654f 100644
+--- a/net/ipv4/route.c
++++ b/net/ipv4/route.c
+@@ -2575,12 +2575,16 @@ 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;
+-- 
+2.39.5
+
+