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 398C42E2665; Mon, 20 Apr 2026 16:01:38 +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=1776700898; cv=none; b=SkZr9Ec8dcUpciSieFejBZPGbbxenDljZ/ttSI+BB9sfukSpXRx2usL3Bn+pRt1AsvN+520YTac04CG0pGDJ8fD5mhXtwPwwkEXq836RrYhTSZK3AcroaynSAtATHydYuwgH/M7xzCQwgnn9I7oILBzxexcSpQ2U2DeFgWsgSsk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776700898; c=relaxed/simple; bh=8c19x629VirKLS5kfJZ+M3LepCR3jmlApGAFH0vxaGU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=L59ovLGV0Y/crlfBsmMe16T09WQZ6F+NHLk3+yzFPNKpRHriZbOWixz3/APMQWYoL5SHwo/yAqsJwxCg81VJr4n6e5eApM169B03HbXatvABAFpPbauKo6VMpDC0Q3potMiRGgHzzK9bIYVo2E3vsq8E418lNxqstx4UWE/htkQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=cD9QF2QF; 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="cD9QF2QF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C4BC1C19425; Mon, 20 Apr 2026 16:01:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1776700898; bh=8c19x629VirKLS5kfJZ+M3LepCR3jmlApGAFH0vxaGU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cD9QF2QF0wR3gIgDEkhWpcDC9GHLX04UYV8VIbuR9JR9tU0IkJ+5I7iwNILVlOLly 0PO1FJJmqew+ReH4PmNTd5Z/WtjJg6AaKfGOKqtvbAe+pZA4l7tLFtVv4XGZzEXZnE xP2Ua9kFPAjDdAM+ZwH+5jiQtHONno5RzgP0wD/A= 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 6.18 101/198] netfilter: ip6t_eui64: reject invalid MAC header for all packets Date: Mon, 20 Apr 2026 17:41:20 +0200 Message-ID: <20260420153939.239110717@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260420153935.605963767@linuxfoundation.org> References: <20260420153935.605963767@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: 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