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 772D711C83 for ; Mon, 28 Aug 2023 10:27:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EE0A9C433C8; Mon, 28 Aug 2023 10:27:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1693218435; bh=esHf/9YF+LKkgXXJny6twYX6Dg3P59JDD1NRjHV5B98=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Fq2CHK+PvwF8jS3FukPdBFbeaP8zX3lkzLPhQveqyoN0TYmw/I7xYGpiB21AhjrWz +VjUhY3rJNnS4JIpxTfOIpGc3kUQJkpqWlye4S6R9ZpBp5YUSeH9UWlQdNjWB2pLJj bQw8zSpFJr8OR/flPjyQ6+4jJtMXpCYVcQSJNEIA= 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 4.19 057/129] ip_vti: fix potential slab-use-after-free in decode_session6 Date: Mon, 28 Aug 2023 12:12:31 +0200 Message-ID: <20230828101155.383138820@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230828101153.030066927@linuxfoundation.org> References: <20230828101153.030066927@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 4.19-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 15c71b08c2df4..a3536dfe9b16b 100644 --- a/net/ipv4/ip_vti.c +++ b/net/ipv4/ip_vti.c @@ -319,12 +319,12 @@ 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: goto tx_err; -- 2.40.1