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 598A233262B; Mon, 20 Apr 2026 15:51:37 +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=1776700297; cv=none; b=o59GWL67OD6RlyMoLLGO2JLr5VW87yyquFM8c+Q4vAfivlY6KrXDxDQsh9IVvIe9dAPUusgTXPxujVHBb6gdXQuyr6kXeAH7INhhrmg95tOcTlVvYAwok3qOokZAXPrl6eSFmsmBZbYgTLYUCJm8lunVf/cJx+hPdDkF0hnflPs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776700297; c=relaxed/simple; bh=OCyrYU11j39nQ7EzJygEEmM9C+8Pv8dLPSyB98YvHIs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bue0f4Hzvulm1FwcN5+q1b0EZ4W9BtgmGBAH9EVXG6xnnfXxi0eTvVBI2YCji1q5PVDxQg3N5AQnLhTRx0T4Eq0r9FalLLvlZ9eTxlmNaD+Oi32Mwui4ZLJ2NY71qcH5JpmlBTzCdA0DKuuLhi8prS7J1lEVGZAk3lOZCCLwtH4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=aPknwzyb; 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="aPknwzyb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E2668C19425; Mon, 20 Apr 2026 15:51:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1776700297; bh=OCyrYU11j39nQ7EzJygEEmM9C+8Pv8dLPSyB98YvHIs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aPknwzybuLpZYcVsohPittYXb88Qc8liFKX+SaUOTsdS0drNFVyUfapxEDCtyAGk9 M+IT0N8TmyW+wK7w5wRS6tyb6fuL51OFplstG/uayVtz81FTjHxRZEX4E0qU0+fCDx Eh9Lag4CiuQmTf48oh4LESIVV9BFgNzPS+L/KS88= 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 6.19 118/220] netfilter: ip6t_eui64: reject invalid MAC header for all packets Date: Mon, 20 Apr 2026 17:40:59 +0200 Message-ID: <20260420153938.277572443@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260420153934.013228280@linuxfoundation.org> References: <20260420153934.013228280@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 6.19-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