From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 A554D3D6CA9; Fri, 24 Apr 2026 13:37:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777037831; cv=none; b=TrzmJG7VtTsltSPMefMGalev0giJCPCRCWSo8GN41x6eChhCKgOV5XUFieBDIYtjWLXbOW7rdEMC3jBAKPk2phiL/8/fliRnjvEuecIjHsQT5buv2GWYve6DmxEkgLX70/M8RQbWBFhygRi0MQ+MA1LjXXGCqcFP6BtG/veSng8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777037831; c=relaxed/simple; bh=oxMuBjiYTEVe496KLRQd4fs0CTmhx+88MMVp0zLYPHU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Y6HthAhqLBlUbhCTX2CnuT5Pjs+f1a4Z9bF0BoVqdYXBTNdsfypU1nLuQscWVP6aQmiPN6MHKmpXyGr6rjT7BRoTxbMZpT5LLyqpc7gFYr46u5d7Hexspxo0ZCD4yCttHqxDeTPC2w0IGNMx4KeO53wc1AEoUhn+XCCOcqMGv7U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=GCAeuxxu; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="GCAeuxxu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3A7C8C19425; Fri, 24 Apr 2026 13:37:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1777037831; bh=oxMuBjiYTEVe496KLRQd4fs0CTmhx+88MMVp0zLYPHU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GCAeuxxu3SmNmGWByIg9LIxUcyGADlAz42fZzfPROV4XJeOcLe3nAZcuLpMP1iui2 Uk25q3Vut4x6bAqg+PaBatBSii0ye54qD2tbDJD+272rvXL3TQ+eC32x5PFJVmFezu 1dFuE++UFKCsO9Xh+8vc3fue6aPOhZ8bzOMQqVCQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yifan Wu , Juefei Pu , Yuan Tan , Xin Liu , Ren Wei , Zhengchuan Liang , Ren Wei , Florian Westphal , Sasha Levin Subject: [PATCH 6.6 054/166] netfilter: ip6t_eui64: reject invalid MAC header for all packets Date: Fri, 24 Apr 2026 15:29:28 +0200 Message-ID: <20260424132544.152867945@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260424132532.812258529@linuxfoundation.org> References: <20260424132532.812258529@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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zhengchuan Liang [ Upstream commit fdce0b3590f724540795b874b4c8850c90e6b0a8 ] `eui64_mt6()` derives a modified EUI-64 from the Ethernet source address and compares it with the low 64 bits of the IPv6 source address. The existing guard only rejects an invalid MAC header when `par->fragoff != 0`. For packets with `par->fragoff == 0`, `eui64_mt6()` can still reach `eth_hdr(skb)` even when the MAC header is not valid. Fix this by removing the `par->fragoff != 0` condition so that packets with an invalid MAC header are rejected before accessing `eth_hdr(skb)`. Fixes: 1da177e4c3f41 ("Linux-2.6.12-rc2") Reported-by: Yifan Wu Reported-by: Juefei Pu Co-developed-by: Yuan Tan Signed-off-by: Yuan Tan Suggested-by: Xin Liu Tested-by: Ren Wei Signed-off-by: Zhengchuan Liang Signed-off-by: Ren Wei Signed-off-by: Florian Westphal Signed-off-by: Sasha Levin --- net/ipv6/netfilter/ip6t_eui64.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/ipv6/netfilter/ip6t_eui64.c b/net/ipv6/netfilter/ip6t_eui64.c index d704f7ed300c2..da69a27e8332c 100644 --- a/net/ipv6/netfilter/ip6t_eui64.c +++ b/net/ipv6/netfilter/ip6t_eui64.c @@ -22,8 +22,7 @@ eui64_mt6(const struct sk_buff *skb, struct xt_action_param *par) unsigned char eui64[8]; if (!(skb_mac_header(skb) >= skb->head && - skb_mac_header(skb) + ETH_HLEN <= skb->data) && - par->fragoff != 0) { + skb_mac_header(skb) + ETH_HLEN <= skb->data)) { par->hotdrop = true; return false; } -- 2.53.0