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 6EAD717B418; Sun, 7 Jun 2026 10:15:00 +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=1780827301; cv=none; b=XOWl6hLy0+vrN9uv5r47pwOwEbPEyeOjPo69wWNATEURWqG+FVi/8G5QyAUqxkGVLj163Y2fFB0HF3iyw/MazXPYSEbqBa3p6dCIdRzbdmEuwjLKuoyTErxYlsWZIr0cIYjDm4QxQXPWBZePTtuzun9PGEws5QdieD+/3vJCrAQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780827301; c=relaxed/simple; bh=WNhQqWvxJJGgs+wDlOyH/mdoI7vn9SZaEt46WedtQBk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=H9bge/7xCajgC453wHxOVflfYISdA9HPnW4Kmymb0vmOrP2nMJJGdahQSB9+OB1ZCltG8F71OK5VTi7WYXlIRTyIiL+zgzwtTEg+iZUxI6Qsrvk5hlfnJ4Lx/4wd/QHHMIE3jtHZzHWUnoGMyRaG/VGARRWV/grd+Ey+BpvZR/w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=R5bgQjNu; 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="R5bgQjNu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C2BBF1F00893; Sun, 7 Jun 2026 10:14:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780827300; bh=I7rIoXRgoHgyiWXvHd6UmcPyzBmj0qOnnZfs+0ztr2s=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=R5bgQjNuO59s/qpZhL7xF6DFNcgzf5L57TD+zHISRXYDLARd/APfqR+QuNOmbGeXq zzpByUND8cJ62YBjigkiT/8U4yFFiSBMNzLO0HKzOh14wm8oVFSMf9lEwCKZxxhRub ewdbfUmzwGGwzayCb0+mimdbFrfFjXMKz+/9q4a4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Stefano Brivio , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.18 055/315] vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu() Date: Sun, 7 Jun 2026 11:57:22 +0200 Message-ID: <20260607095729.624110156@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260607095727.528828913@linuxfoundation.org> References: <20260607095727.528828913@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 7d9ef0cb271555d8cf39fefe6c981e1493b25ecf ] 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 Reviewed-by: Stefano Brivio Link: https://patch.msgid.link/20260525203642.2389723-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- 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 d2d0e0bd43716c..a4ff66e354f532 100644 --- a/drivers/net/vxlan/vxlan_core.c +++ b/drivers/net/vxlan/vxlan_core.c @@ -2532,7 +2532,7 @@ 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); @@ -2606,7 +2606,7 @@ 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), -- 2.53.0