From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 E267E347515; Wed, 20 May 2026 18:19:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779301148; cv=none; b=nG3dmFhH+/bzzqW5qEwoxA4bX25JLVnnYLcuXGi3ZVfpI9G2LJbmq8HRAmoPUcxMqOaDMe4+HdRPxIT/5XdbXBiqgz7OW0PDgti9DnJKzBbvZOPt1wIFojUfq1HMuR6nEl/tGx61PFpMKcg/5Vdt69mUQeZc6z70n3lagMXKru0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779301148; c=relaxed/simple; bh=w/d3Le4xsE9S9jJyOnxcYWFRHgVH14aSJu8Q2FvhkAg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Xob2IIP6Hxxhv6CkgsaLrA90Cr6TzN5VB1Xk6kLF4FvHkx/YBhQdLDyM/9wjJEiS78s/AnO5fbqzWq/jQQqMrrehwvJO3je0imxU2A92OyLSfjXYnk+ox+UXfFpcAI09XpLNfazXBv6b2q/mPhMUWluwVAwHraOI/sW15//sEP4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=hG5jT7oZ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="hG5jT7oZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 023FE1F000E9; Wed, 20 May 2026 18:19:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779301146; bh=8JYREuzL1OuzzIo+vSAyaWr+OyXXEH3Pt4kOC3guJ90=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=hG5jT7oZKmfQTW7C/CtoPV7uyHVeCVXoxkpSNzO8VUB42KMpanJiDJub/+zO64kU7 jndtGnapQekb1/Tg90h62e6Jc90AT1EOVFjiaRVnugM1jSMrAtZnO4llaX3JpLm6Dr R1vtE0/5bWpSWY23zmUHV+pfra+2kmbzaVoZVGXU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dudu Lu , Vadim Fedorenko , Eric Dumazet , Paolo Abeni , Sasha Levin Subject: [PATCH 6.12 445/666] macvlan: fix macvlan_get_size() not reserving space for IFLA_MACVLAN_BC_CUTOFF Date: Wed, 20 May 2026 18:20:56 +0200 Message-ID: <20260520162120.915519891@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260520162111.222830634@linuxfoundation.org> References: <20260520162111.222830634@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dudu Lu [ Upstream commit fa92a77b0ed4d5f11a71665a232ac5a54a4b055d ] macvlan_get_size() does not account for IFLA_MACVLAN_BC_CUTOFF, but macvlan_fill_info() conditionally includes it when port->bc_cutoff != 1. This causes nla_put_s32() to fail with -EMSGSIZE when the netlink skb runs out of space, triggering a WARN_ON in rtnetlink and preventing the interface from being dumped. The bug can be reproduced with: ip link add macvlan0 link eth0 type macvlan mode bridge ip link set macvlan0 type macvlan bc_cutoff 0 ip -d link show macvlan0 # fails with -EMSGSIZE The bc_cutoff feature was added in commit 954d1fa1ac93 ("macvlan: Add netlink attribute for broadcast cutoff"), which added the nla_put_s32() call in macvlan_fill_info() but missed adding the corresponding nla_total_size(4) in macvlan_get_size(). A follow-up commit 55cef78c244d ("macvlan: add forgotten nla_policy for IFLA_MACVLAN_BC_CUTOFF") fixed the missing nla_policy entry but still did not fix the size calculation. Fixes: 954d1fa1ac93 ("macvlan: Add netlink attribute for broadcast cutoff") Signed-off-by: Dudu Lu Reviewed-by: Vadim Fedorenko Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260413085349.73977-1-phx0fer@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- drivers/net/macvlan.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c index b43a1221a5908..e778367c1d296 100644 --- a/drivers/net/macvlan.c +++ b/drivers/net/macvlan.c @@ -1678,6 +1678,7 @@ static size_t macvlan_get_size(const struct net_device *dev) + macvlan_get_size_mac(vlan) /* IFLA_MACVLAN_MACADDR */ + nla_total_size(4) /* IFLA_MACVLAN_BC_QUEUE_LEN */ + nla_total_size(4) /* IFLA_MACVLAN_BC_QUEUE_LEN_USED */ + + nla_total_size(4) /* IFLA_MACVLAN_BC_CUTOFF */ ); } -- 2.53.0