From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qk1-f200.google.com (mail-qk1-f200.google.com [209.85.222.200]) (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 9384243CE79 for ; Thu, 23 Jul 2026 14:42:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.200 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784817784; cv=none; b=EsoW6cWfcATQPWQDQzOQLdkqHgKJqcsKBWbs/wxwFhFMoToFdxsYw8Un+KvtXqnpgUgZLILVu0ZxtqB5taVX+plWz/qhCj1F4eSjlEWZNvkCOHy+yzSGjVsyfczIcJWDZUBH6vlcIkpKIsMa7SQX5B7r3cJpTWNhzd+yR4G/0UM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784817784; c=relaxed/simple; bh=SaGT5/k0Hq7us1Xh96BcYHTQxGZSs402OfH8hNSQErY=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=b9lTY0NF2W+7iL5BtVexfn/ERUHC+bYIyMZFpRMbLjLkD6jlOenksTeYWClhWKY/yo4edSa4opY0g0PRkgEC7RL5QZlR1aFPytzy5djSEVtTubbWGHKLHsH0phsTbtOFCa7TCkXnS8m3FQY7yemuNoj2kapcsvPyk7UqvZ8RCUM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=GjkyRkmd; arc=none smtp.client-ip=209.85.222.200 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="GjkyRkmd" Received: by mail-qk1-f200.google.com with SMTP id af79cd13be357-91931144870so138025585a.1 for ; Thu, 23 Jul 2026 07:42:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1784817776; x=1785422576; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=7G6+WmalGeshMr5rrbPWKhucx6Kb/G0FkKHu8ELLz48=; b=GjkyRkmdjlx0WuRJ2NpsCYJypkU2QOcewKBHWz+aVDgWwHBDc8G0WeQP+SW9NOUVvH cx+0hlT788gmTvuGLgxRhMHekJjEH9/qL8sx/1JJsT1DOsoH7Sp5lQtrOZD3c0mBzvk0 3iL5xnStIVLUTQRRb+TEIeISfNXUKZw4td1a5Tbj5hdJqO/iuJ17946sdv5OPiFxmM2c HXGk1mJin1J0Vktxk+kOZ8iJSalWrTGaffpuwEb8fTYKNaagcU7mh0q63zeQqz0YyL5q oUg4i1n74/+NEG15gzbX9gLaRhziqFBjJpQSCJozdXxsQZDWBakbjvNULLDBFBHdsSwt wI+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1784817776; x=1785422576; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=7G6+WmalGeshMr5rrbPWKhucx6Kb/G0FkKHu8ELLz48=; b=MVrZ+/zOG9Sg3Yr9KmWqtV/S8TApfkz8Obqe+YydJHAlbYWjStMIAg/tr/K2xZDNVn KILnwHtqX72IXwE7a9z33x0ZYRGHv7XEAiVXyGkZOglX5h+vlddZco8IyDd5/TK/CWgN oAok4CIcZBkt2NupIswGm+dETHm4aYt7dYABES6skIDjgX50k7+AOm8f/fSLQkK7yTBx 4WXwy/oxPbH921lMaVRkleII5089S52/KgCYcBob5N0AvrItT3X7yiiwzvGiBC8Yudeo 2aGpBSV1c7M78ekc7vIlLxHHcmpHdSuzTL9/vtfman1eypc4crGqRXrNwjdsOuOt9RLr kWUA== X-Forwarded-Encrypted: i=1; AHgh+Ro2MW6umkp7dFK0ymfPsmuSlySEj/nrLu8F06IXOziyyKQFZamPZxOBGekSYNSseA3GCXLxp4M=@vger.kernel.org X-Gm-Message-State: AOJu0YyHWIWz72VK2ReieLdiZ6T5L9RM1ZRGw9USK+TvCz/ezWWBG+PI pP7O10jfLzBafRxuESINixivok/eqefeDM48wY1m4wRLD7tV1gnjZNZzuIMp0tMd480IKK2CYOa nJgFTDn9tVdaByQ== X-Received: from qkww19.prod.google.com ([2002:a05:620a:953:b0:92e:e46b:a01b]) (user=edumazet job=prod-delivery.src-stubby-dispatcher) by 2002:a05:620a:480b:b0:930:f9a6:11ac with SMTP id af79cd13be357-93103a59d1dmr315209785a.71.1784817775196; Thu, 23 Jul 2026 07:42:55 -0700 (PDT) Date: Thu, 23 Jul 2026 14:42:47 +0000 In-Reply-To: <20260723144249.759100-1-edumazet@google.com> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260723144249.759100-1-edumazet@google.com> X-Mailer: git-send-email 2.55.0.229.g6434b31f56-goog Message-ID: <20260723144249.759100-4-edumazet@google.com> Subject: [PATCH net 3/5] vxlan: use neigh_ha_snapshot() in route_shortcircuit() From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: Simon Horman , Ido Schimmel , Andrew Lunn , netdev@vger.kernel.org, eric.dumazet@gmail.com, Eric Dumazet , stable@vger.kernel.org Content-Type: text/plain; charset="UTF-8" The neighbour hardware address n->ha can be updated asynchronously by the neighbour subsystem, protected by n->ha_lock seqlock. Reading n->ha without holding the seqlock loop can lead to torn reads or reading a partially updated MAC address. Use neigh_ha_snapshot() in route_shortcircuit() to safely copy n->ha under read_seqbegin()/read_seqretry() lock protection before using it. Note that arp_reduce() and neigh_reduce() seem to have the same issue left for future patches. Fixes: e4f67addf158 ("add DOVE extensions for VXLAN") Cc: stable@vger.kernel.org Signed-off-by: Eric Dumazet --- drivers/net/vxlan/vxlan_core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c index fb4a706cd5786d1937b1922acced31ffdb187c2f..10dd19eec09e266197ee51330a652f4e76c9643a 100644 --- a/drivers/net/vxlan/vxlan_core.c +++ b/drivers/net/vxlan/vxlan_core.c @@ -2159,9 +2159,11 @@ static bool route_shortcircuit(struct net_device *dev, struct sk_buff *skb) } if (n) { + u8 haddr[ETH_ALEN]; bool diff; - diff = !ether_addr_equal(eth_hdr(skb)->h_dest, n->ha); + neigh_ha_snapshot(haddr, n, dev); + diff = !ether_addr_equal_unaligned(eth_hdr(skb)->h_dest, haddr); if (diff) { if (skb_cow_head(skb, 0)) { neigh_release(n); @@ -2169,7 +2171,7 @@ static bool route_shortcircuit(struct net_device *dev, struct sk_buff *skb) } memcpy(eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest, dev->addr_len); - memcpy(eth_hdr(skb)->h_dest, n->ha, dev->addr_len); + memcpy(eth_hdr(skb)->h_dest, haddr, dev->addr_len); } neigh_release(n); return diff; -- 2.55.0.229.g6434b31f56-goog