From nobody Fri Sep 25 07:23:46 2026 Received: from smtpout-03.galae.net (smtpout-03.galae.net [185.246.85.4]) (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 611AC36308D; Tue, 15 Sep 2026 14:08:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.85.4 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789481329; cv=none; b=SUhM49hi/67ZkYeVIGUsSW2lUptpCp7Zy3GBvp/G8qXonOjvzoeqHazvzGJTbqKJ+3LzezfeUMdMRFXjav7TaCPLH8wsn8fkY08MBDEje35ia+egJ82GXrZJ9rMMeyFqBEIniadN87bK8I9+Q41NMRmI8PLQReIy1J5Ej5TBJmU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789481329; c=relaxed/simple; bh=4v6n+xqh5GZs4GinReU0YRNIA+IVQq/XiGYlNXPEvfo=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=qcHxrkp5Ly08zPqrzoQaNZdBrbC7xuXh0Ynpt+ZrdGZ4/PXGhs0LqAQNZyecsiJe46zMVhmWlxzKmD5VS259Fn2LOFLP4k0oqk4TMlBBId1VVLOUEHi6x0bnhkV2h8tl1N7wT5DqNJdrFT90JEbVrkOZ1gOkHqz5qidCOnsce5A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=X+DtQoUk; arc=none smtp.client-ip=185.246.85.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="X+DtQoUk" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-03.galae.net (Postfix) with ESMTPS id 87AD04E40639; Tue, 15 Sep 2026 14:08:44 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 5384F602B0; Tue, 15 Sep 2026 14:08:44 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 6880E11C7B007; Tue, 15 Sep 2026 16:08:34 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1789481319; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding; bh=1v8WmV1lzmVvxTEijsOq/fqJH2jWLGKp2l9KoEWhH+I=; b=X+DtQoUk58tgwjATpWdhlg3I/XDyP5aatscFgJHmFwtLrjBeAZKIOosjzmuv3VLncgoEWy 5wULR1RU4884i6EDzcJIJDOmzddzTcgnPcS+v/gFVVo9kzXXpCRHijfFNVnVfrdmtyUmeI 9rgtimCcIYes3PqVMSUbsCCIvV2EpOsGSZUY9z2+WHHiR2y9KTYy4CS0Cx5Wvjwhlg0CvG uo2VsHzFlOjTP0PrbxEG0vXXYP+I84KtsGvEXHJlMui2ivgPd41ou89JyvSLYYlHhf6Up/ r3J/7AzSmA2jCSeaf1TaK0Q21HneUgAQOP5Yd6ZsgDs1fa7DbtOnOZqCqKhpNw== From: "Miguel Gazquez (Schneider Electric)" Date: Tue, 15 Sep 2026 16:08:32 +0200 Subject: [PATCH 5.15.y] macvlan: inherit needed_headroom and needed_tailroom from lowerdev Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260915-cve-2026-74743-5-15-v1-1-bacf32f2651c@bootlin.com> X-B4-Tracking: v=1; b=H4sIAAAAAAAC/yWMwQ6CMBAFf4W8s0sosG70VwyHUhZdD2haIRrCv 1v0OJPMrEgaTRPOxYqoiyV7TBncoUC4+emqZENm1FV9rE6OKSxKO5C00jbElJ2wNF78GAbfI5f PqKO9f9cLuHRcftD9fZr7u4bXvsS2fQG2hSJHfwAAAA== X-Change-ID: 20260915-cve-2026-74743-5-15-7573a7afcdab To: stable@vger.kernel.org, "David S. Miller" , Jakub Kicinski , Patrick McHardy Cc: Thomas Petazzoni , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Eric Dumazet , Tangxin Xie , Hangbin Liu , Sasha Levin , "Miguel Gazquez (Schneider Electric)" X-Mailer: b4 0.15.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1789481314; l=2806; i=miguel.gazquez@bootlin.com; s=20250708; h=from:subject:message-id; bh=JSAEZ6HJlTAJcObiAa6N//lRVUWeIEAORotoJeReHSA=; b=bgRDsGyWNa8uQsb9c25jnb8S9g7H/sFC2cv1x/lIl+I6LpRuO+Ud4RLJ99J/IE/jKIoB7QrBI HMWLPpiae2OD5uxA5PWo8pYFZK5su+4dkV47cKgmLKI93NXdqbVNfp/ X-Developer-Key: i=miguel.gazquez@bootlin.com; a=ed25519; pk=k/2KI9jkmayaF0ghZ8QYUH9Wm/kFHDhl8QoZ0RHbr4w= X-Last-TLS-Session-Version: TLSv1.3 From: Eric Dumazet [ Upstream commit cef51860becd9700217c81732ca1eb1ea6ed6fe1 ] macvlan devices inherit hard_header_len from lowerdev during macvlan_init(), but leave needed_headroom and needed_tailroom set to 0. When the underlying lowerdev requires extra headroom or tailroom for headers/trailers (e.g. macsec, ipsec, wireguard, tunnels, or veth with rx headroom), upper layers calculating packet headroom and tailroom fail to reserve sufficient space. This can result in reallocation overhead, skb headroom underflows, or KASAN slab-use-after-free crashes when dev_hard_header() / macvlan_hard_header() prepends header data or when lower devices append tailroom. Fix this by: 1. Inheriting needed_headroom and needed_tailroom from lowerdev in macvlan_= init(). 2. Propagating needed_headroom and needed_tailroom updates to attached macv= lans in macvlan_device_event() when receiving NETDEV_FEAT_CHANGE events. Fixes: b863ceb7ddce ("[NET]: Add macvlan driver") Reported-by: Tangxin Xie Closes: https://lore.kernel.org/netdev/CANn89i+1EW-sFNK8xoq98gMbPCeLS7e=3D+= rs9gHfLg5Wj+4x0sw@mail.gmail.com/T/#m16adf0ff972cbfd8066c3a8e656e75eaeb12d0= 21 Signed-off-by: Eric Dumazet Reviewed-by: Hangbin Liu Link: https://patch.msgid.link/20260806141938.287660-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin Signed-off-by: Miguel Gazquez (Schneider Electric) --- drivers/net/macvlan.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c index 86a531ffe9fc..c8c1761908c1 100644 --- a/drivers/net/macvlan.c +++ b/drivers/net/macvlan.c @@ -913,6 +913,8 @@ static int macvlan_init(struct net_device *dev) dev->gso_max_size =3D lowerdev->gso_max_size; dev->gso_max_segs =3D lowerdev->gso_max_segs; dev->hard_header_len =3D lowerdev->hard_header_len; + dev->needed_headroom =3D lowerdev->needed_headroom; + dev->needed_tailroom =3D lowerdev->needed_tailroom; macvlan_set_lockdep_class(dev); =20 vlan->pcpu_stats =3D netdev_alloc_pcpu_stats(struct vlan_pcpu_stats); @@ -1769,6 +1771,8 @@ static int macvlan_device_event(struct notifier_block= *unused, list_for_each_entry(vlan, &port->vlans, list) { vlan->dev->gso_max_size =3D dev->gso_max_size; vlan->dev->gso_max_segs =3D dev->gso_max_segs; + vlan->dev->needed_headroom =3D dev->needed_headroom; + vlan->dev->needed_tailroom =3D dev->needed_tailroom; netdev_update_features(vlan->dev); } break; --- base-commit: 0248c33e835ecbec3a591f93fdaae53f7b90a4d6 change-id: 20260915-cve-2026-74743-5-15-7573a7afcdab Best regards, -- =20 Miguel Gazquez (Schneider Electric)