From patchwork Mon Feb 19 13:48:20 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Justin Iurman X-Patchwork-Id: 13562739 X-Patchwork-Delegate: kuba@kernel.org Received: from serv108.segi.ulg.ac.be (serv108.segi.ulg.ac.be [139.165.32.111]) (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 6AC30364AC; Mon, 19 Feb 2024 13:48:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=139.165.32.111 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708350526; cv=none; b=RQZJRyaTTFsHfNAZqEeBv7dBFCEL9tIOML8nQI7VeMZgtCX402xucMMPH9nAlfKVmFFnj8FuCwd0Xz1kcH3ATvKbLQKrys1rUGxRUK+USqigkQPjr2L0NwqbggT9Kev8BrvIKF7bySbMLLuAfvqG3p9fs1NCiWKID+Fv2lk3B0Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708350526; c=relaxed/simple; bh=pSf/6yBlnsj3efx67HWLfiYU1L7RVALqEg3khS/oWgk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=WgDB6wAQFifO9/9jdthN19OsCg0ntKXAZEiTR/c9FIPURlxYWUrrSutsKrVvNT/obCDB/rGbs+fk0n6rIXenZAFJ2/GggijTm3790nrlF2qpCrpEyAg7CbgvXdvXBJTnZXrEYYaC4RSxuSX5jzNE2eGBRGvDNHNhdnNa0lKL16E= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=uliege.be; spf=pass smtp.mailfrom=uliege.be; dkim=pass (2048-bit key) header.d=uliege.be header.i=@uliege.be header.b=yYKfUoTU; arc=none smtp.client-ip=139.165.32.111 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=uliege.be Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=uliege.be Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=uliege.be header.i=@uliege.be header.b="yYKfUoTU" Received: from ubuntu.home (125.179-65-87.adsl-dyn.isp.belgacom.be [87.65.179.125]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by serv108.segi.ulg.ac.be (Postfix) with ESMTPSA id 68FA1200EEA2; Mon, 19 Feb 2024 14:48:42 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 serv108.segi.ulg.ac.be 68FA1200EEA2 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=uliege.be; s=ulg20190529; t=1708350522; bh=k3BbLM+W3IY++z5FItf1PQyWOHVjGz95oS2lZDTR3f4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yYKfUoTUzmsVCectPHw4LnIoT1WpSIG0UBRrWDrhPeeZlOaPgh9OeeewqA6xrPtX9 9GoHDb+2JLL6/HJ7AOXmsji3k0gstpmELeYP9guCOXHc1xX62F2GnsRRNL2Q/ylpZf Q4/T0bu10qDMmyp7t+plWHOWl6OwUPXeWiewLyei0rrH48gAa7+M1uh6QISn+034Qv H23KcBiMBZx1MdJRDFvPauyCX2r5DL8Rorw8fJTgl3hlxRZ8HBUSOQa/avspAE8hM0 KYjF7yiG6rj8iPsIPp0vnfF1YD05efSEe2qHuoHWXQmapc9ynZmyqil6loTdD74scz tVmlmrBbt2oig== From: Justin Iurman To: netdev@vger.kernel.org Cc: davem@davemloft.net, dsahern@kernel.org, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, linux-kernel@vger.kernel.org, justin.iurman@uliege.be Subject: [PATCH 1/2] Fix write to cloned skb in ipv6_hop_ioam() Date: Mon, 19 Feb 2024 14:48:20 +0100 Message-Id: <20240219134821.14009-2-justin.iurman@uliege.be> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240219134821.14009-1-justin.iurman@uliege.be> References: <20240219134821.14009-1-justin.iurman@uliege.be> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org ioam6_fill_trace_data() writes inside the skb payload without ensuring it's writeable (e.g., not cloned). This function is called both from the input and output path. The output path (ioam6_iptunnel) already does the check. This commit provides a fix for the input path, inside ipv6_hop_ioam(). It also updates ip6_parse_tlv() to refresh the network header pointer ("nh") when returning from ipv6_hop_ioam(). Fixes: 9ee11f0fff20 ("ipv6: ioam: Data plane support for Pre-allocated Trace") Reported-by: Paolo Abeni Signed-off-by: Justin Iurman --- net/ipv6/exthdrs.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c index 4952ae792450..02e9ffb63af1 100644 --- a/net/ipv6/exthdrs.c +++ b/net/ipv6/exthdrs.c @@ -177,6 +177,8 @@ static bool ip6_parse_tlv(bool hopbyhop, case IPV6_TLV_IOAM: if (!ipv6_hop_ioam(skb, off)) return false; + + nh = skb_network_header(skb); break; case IPV6_TLV_JUMBO: if (!ipv6_hop_jumbo(skb, off)) @@ -943,6 +945,14 @@ static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff) if (!skb_valid_dst(skb)) ip6_route_input(skb); + /* About to mangle packet header */ + if (skb_ensure_writable(skb, optoff + 2 + hdr->opt_len)) + goto drop; + + /* Trace pointer may have changed */ + trace = (struct ioam6_trace_hdr *)(skb_network_header(skb) + + optoff + sizeof(*hdr)); + ioam6_fill_trace_data(skb, ns, trace, true); break; default: