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 2F546219303; Sat, 30 May 2026 18:22:17 +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=1780165338; cv=none; b=TQ6BDX7rgldDxQ5pglWmX9pKJnxSnGXL+XAd2oyHbdSF1MYDjQT/iEcvXYVy2GETY/ljhn+wfHqmxjpar/vLAFhCxO/6taHIl0zVJLNNweRFkVt387eckWQoGh/FiCU0Svw+gfiCNyKjtrvaLoNk8ZDtpYxtl+O12XWStshZldY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780165338; c=relaxed/simple; bh=56+UWgFkz6O5Ru7Ag/plZec5JtEitiYTSjvST7om9Q0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qPt9Ct3+9SpgHunFGfmdi8ekB8E3fbyghWqoFXmnbFNspX/RBhYp1EQM8uJ0RKzlvNBcYk+c/SCKk3M7sBwpHAbwoYVz3H8GN1rPW+SvsKk6CIMzENM/tdno7JLe+5zo4hS9Ah2ZRoAVpO8dPjn2F0ukqmDDa7/BNLrfvhUeO2o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=W1UeO6fh; 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="W1UeO6fh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7382E1F00893; Sat, 30 May 2026 18:22:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780165337; bh=vWdNMl4gPPZdX7m+DiaXkLBxooIh+UJQSd6p+KB0pOQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=W1UeO6fhWwqBZLTV5jUx93GZ+HDR1oz/Y8cR1SmCqSm7gpNawesAk375zthP5H5TK rN6JIpRNyQGZgqtOSA5vdJMCX2KwNdQSZVFteuybPdM7SLaQvGJh11CGSgdGFAaljI vK2+kQcbiCs65Qw5EEXMUKc5OXGEYlei8sMcpw2k= 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 5.10 031/589] netfilter: ip6t_eui64: reject invalid MAC header for all packets Date: Sat, 30 May 2026 17:58:32 +0200 Message-ID: <20260530160225.401254377@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160224.570625122@linuxfoundation.org> References: <20260530160224.570625122@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 5.10-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