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 52A3211C83 for ; Mon, 28 Aug 2023 10:15:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CB544C433C8; Mon, 28 Aug 2023 10:15:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1693217737; bh=kV4wPRz54hOPq8Uz1932qu8N+p0bUviTuhOLhPIv/C8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PE3cXi4gOx5aIQE6CrFV/9M1GWdZ6fkfAAHKKZGJUYOujTQ3EYFwYF0ld+qVUNzaQ pNqwArUQh3J/qkf3k4+rfErMmxe++2yfxAnmvHmE1ur5n2SGzMl4Fcr5+8E2jQna4f Xk+tK4zZ9vt6wDsmY3gIa1QXayibj1kEHkTm1soQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zhengchao Shao , Steffen Klassert , Sasha Levin Subject: [PATCH 4.14 22/57] ip_vti: fix potential slab-use-after-free in decode_session6 Date: Mon, 28 Aug 2023 12:12:42 +0200 Message-ID: <20230828101145.046226410@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230828101144.231099710@linuxfoundation.org> References: <20230828101144.231099710@linuxfoundation.org> User-Agent: quilt/0.67 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 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zhengchao Shao [ Upstream commit 6018a266279b1a75143c7c0804dd08a5fc4c3e0b ] When ip_vti device is set to the qdisc of the sfb type, the cb field of the sent skb may be modified during enqueuing. Then, slab-use-after-free may occur when ip_vti device sends IPv6 packets. As commit f855691975bb ("xfrm6: Fix the nexthdr offset in _decode_session6.") showed, xfrm_decode_session was originally intended only for the receive path. IP6CB(skb)->nhoff is not set during transmission. Therefore, set the cb field in the skb to 0 before sending packets. Fixes: f855691975bb ("xfrm6: Fix the nexthdr offset in _decode_session6.") Signed-off-by: Zhengchao Shao Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin --- net/ipv4/ip_vti.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/ipv4/ip_vti.c b/net/ipv4/ip_vti.c index 33a85269a9f26..d43180dd543e3 100644 --- a/net/ipv4/ip_vti.c +++ b/net/ipv4/ip_vti.c @@ -325,12 +325,12 @@ static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) switch (skb->protocol) { case htons(ETH_P_IP): - xfrm_decode_session(skb, &fl, AF_INET); memset(IPCB(skb), 0, sizeof(*IPCB(skb))); + xfrm_decode_session(skb, &fl, AF_INET); break; case htons(ETH_P_IPV6): - xfrm_decode_session(skb, &fl, AF_INET6); memset(IP6CB(skb), 0, sizeof(*IP6CB(skb))); + xfrm_decode_session(skb, &fl, AF_INET6); break; default: dev->stats.tx_errors++; -- 2.40.1