From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qt1-f201.google.com (mail-qt1-f201.google.com [209.85.160.201]) (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 1247326B764 for ; Mon, 25 May 2026 20:36:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779741406; cv=none; b=a/qOtK0TFoIPZKxvXzcShJglTs36GX7NYwEjkTr39B8Eqqy0nB2QxRpLiMLPljXwpUl209tmWgx+UvkSsHn6Uf00TZhHv6i3evBhnohC/Tz5q492AKJBgFy5fxZN6W8qX5VSwigwEeQR3ObXdNJkxmzbhILzmE100QJSQmywTUo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779741406; c=relaxed/simple; bh=S/7f/4lLI1yx9DjoJjzbhWh7NU9cRgAZKFx9X35ajPY=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=OnbfH8xogXVAjTr/BsY7HviDfPlqaysvsz03yVd2nRnXS1Eav/rwAimLsdoyJpe3NJos59+J/B8coiYkG6B05U+tkCX/RxMGzJrB3K2/37/M6BgQFEEn16Yd/9ypnJWFbB616ipl4u0YdjwpUrvROJZkmoTrr1XnN4KlLsOP93w= 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=XFI4aXvz; arc=none smtp.client-ip=209.85.160.201 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="XFI4aXvz" Received: by mail-qt1-f201.google.com with SMTP id d75a77b69052e-516d1a8a6c8so28425471cf.2 for ; Mon, 25 May 2026 13:36:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1779741404; x=1780346204; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=c+5bjCNG+m99Wa5Y3Z9UVTI0tHsz1+fdgadzgclby2U=; b=XFI4aXvzBXyZ1FpenYYuN3i/GUubVYVXRoZLFg3VN5MYo1OgInAzfPnDie0aOFx/Uo izaauf3PPU9bJ1iDD58zkuVwa+jbX5YmBS0GcKPu2klrH+1ctJxpF6UAEihEm1GXO2AX Y5nZTGidN0+rEC3ZJlRv4rScQ9xhDiy33O4hD/ZePltZyykK0JQzMCIjTpymQ1ORWe56 pc3W/5r7q/MPS+JaMfuL4oHgFPXdmjKT1JfT9zdPW0rPMm+QEQkPwyqEHtfoAEdojpO8 x3wnMfumoJy5erSQSB/o6w8fUIYKTXS+vD5iLw7aND0CIPKjpa0jpJ1e9tsRop5/Brj2 Su1A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779741404; x=1780346204; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=c+5bjCNG+m99Wa5Y3Z9UVTI0tHsz1+fdgadzgclby2U=; b=HfM/me44yhN+GoOSI7xQ2UmGT8GOrHTaUWJrrZHh6AmMm1G5iumiqJS45RyTqe3p7L Y7NdvvsEMb/ixWMTFSjFnrwG3VD22GDzA1cZbjsBX8tLu8Obhp+og+0DzY6rBPxPWgZ8 DxGEEG6Uu0K11VPWG4/zILlJ3qCu2CiednRlYW3no8B2J+wYh5sPpUIMK0UZTSybFVZY 6iSqdLyAvrWo6Cp+JQPQDwT6RhM9tTgHWGlyMMxIHIIRQKfTMD3NLes+D9VPd33XiZfl NN+3wQw+1iAiV8J0fmptyQfK8W0+ARtdzaolRbHyuRflq2KbPoIW146YYiCyvk6Chfrl 7ZqA== X-Forwarded-Encrypted: i=1; AFNElJ9sufj1pxZ5hHxJ+M3UecAfK/L8lCwK7YphLRFg8yrJ8Ta58C8mORQMzCbSOWGHvX8rpTmHDzs=@vger.kernel.org X-Gm-Message-State: AOJu0YyFXgNGyAbIdiFZqL71A1G1ZE8jH6RZ1g7JlgwJ8Uk3HakemFMT FNwDKht5gqsFBfWG4qEetdhHhPQgOg3zHeWy2lSRkR1jJUVVcL3xwyYvkIzIJDHlV7DM1NkGGL/ 1bURVVeEUHG6Yaw== X-Received: from qtqh18.prod.google.com ([2002:ac8:5492:0:b0:514:c2a9:fcc]) (user=edumazet job=prod-delivery.src-stubby-dispatcher) by 2002:a05:622a:995:b0:50f:b1e6:a8f6 with SMTP id d75a77b69052e-516d444e163mr233607991cf.26.1779741403771; Mon, 25 May 2026 13:36:43 -0700 (PDT) Date: Mon, 25 May 2026 20:36:42 +0000 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.54.0.746.g67dd491aae-goog Message-ID: <20260525203642.2389723-1-edumazet@google.com> Subject: [PATCH net] vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu() From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: Simon Horman , Ido Schimmel , David Ahern , netdev@vger.kernel.org, eric.dumazet@gmail.com, Eric Dumazet , Stefano Brivio Content-Type: text/plain; charset="UTF-8" skb_tunnel_check_pmtu() can change skb->head. Reusing old_iph afer skb_tunnel_check_pmtu() can cause an UAF. Use instead ip_hdr(skb) as done in drivers/net/bareudp.c and drivers/net/geneve.c. Found by Sashiko. Fixes: 4cb47a8644cc ("tunnels: PMTU discovery support for directly bridged IP packets") Signed-off-by: Eric Dumazet Cc: Stefano Brivio --- drivers/net/vxlan/vxlan_core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c index e88798497503b53cbaf5bffad72cf3e1cc956410..b5b1253ac08ba46933249b06f19d1fe5a2ffd114 100644 --- a/drivers/net/vxlan/vxlan_core.c +++ b/drivers/net/vxlan/vxlan_core.c @@ -2531,7 +2531,7 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, goto out_unlock; } - tos = ip_tunnel_ecn_encap(tos, old_iph, skb); + tos = ip_tunnel_ecn_encap(tos, ip_hdr(skb), skb); ttl = ttl ? : ip4_dst_hoplimit(&rt->dst); err = vxlan_build_skb(skb, ndst, sizeof(struct iphdr), vni, md, flags, udp_sum); @@ -2605,7 +2605,7 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev, goto out_unlock; } - tos = ip_tunnel_ecn_encap(tos, old_iph, skb); + tos = ip_tunnel_ecn_encap(tos, ip_hdr(skb), skb); ttl = ttl ? : ip6_dst_hoplimit(ndst); skb_scrub_packet(skb, xnet); err = vxlan_build_skb(skb, ndst, sizeof(struct ipv6hdr), -- 2.54.0.746.g67dd491aae-goog