From patchwork Thu Feb 1 08:38:15 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Antoine Tenart X-Patchwork-Id: 13540807 X-Patchwork-Delegate: kuba@kernel.org 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 3C10615957F for ; Thu, 1 Feb 2024 08:38:20 +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=1706776701; cv=none; b=VCoQh4+Sgn59nwolTFfJax3uJNaZlSSEreFdi0t8RNl36IFyvZXr/XduH8NmUSXWZZZXbWsYDtBP5GF78yI1NDS47SRy6YH2PUWAJrWhzVC8hhN075wphXfBjhv5hL0nPAn6hQEeEg6txU2Qh9RvQjzkvSABztCVBlYwwrNl+6k= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706776701; c=relaxed/simple; bh=UeDEbBS4ZCI5n4U/aoXtMkSEMN9vEAaDGmiMdoWBGEw=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=ThqkIIOsQFkNLMiIVTCS4pbGbFtrlu/Dw+GAPCCrX5xsRBHM0OftL3CrkgzwDY+jI8NIWTK1Vrqyf/zO9BU9f2vsRALwpajEy6wkN6j+CEenHjJtokU70Fnuw79H7VWclBlOl7P0dvulmKQuU0UfWTFvcgAjPQk9TDKSGuzJbMQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cupDJHKg; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="cupDJHKg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5E884C433F1; Thu, 1 Feb 2024 08:38:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706776700; bh=UeDEbBS4ZCI5n4U/aoXtMkSEMN9vEAaDGmiMdoWBGEw=; h=From:To:Cc:Subject:Date:From; b=cupDJHKgjzXOxEfkzQBOgEf5QZWbZOC7nIDPf2U4oAuu9pvwdHKv9AVuegv+fUaZ0 Yj+qDbeSsgChuwxJ2/MipiEteowsTFCh7FsLiV1+elgjANNP5c256QiW/rQ+MNxeFE Bo+vpjBkbjqNQpNnd2Xq0NULGa7U5HfOIwIoC0h+Hx8eyK8eo2Oa4pC5oFDpQ1BM/Q jpmKCZ8XU+uEDSz7NDSxPFi1JjCSLvwsSv+59ENK8bA+U+VPneTQ8dV3rQHkSPMT// QZnD2V3PV+RaNphgl1xrD/LDa3Z4KHcQHtHVOrHRI6ra7/qpsxfq6zzP29gJZurDi3 XsJxF/E4aW/mg== From: Antoine Tenart To: davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com Cc: Antoine Tenart , netdev@vger.kernel.org Subject: [PATCH net] tunnels: fix out of bounds access when building IPv6 PMTU error Date: Thu, 1 Feb 2024 09:38:15 +0100 Message-ID: <20240201083817.12774-1-atenart@kernel.org> X-Mailer: git-send-email 2.43.0 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 If the ICMPv6 error is built from a non-linear skb we get the following splat, BUG: KASAN: slab-out-of-bounds in do_csum+0x220/0x240 Read of size 4 at addr ffff88811d402c80 by task netperf/820 CPU: 0 PID: 820 Comm: netperf Not tainted 6.8.0-rc1+ #543 ... kasan_report+0xd8/0x110 do_csum+0x220/0x240 csum_partial+0xc/0x20 skb_tunnel_check_pmtu+0xeb9/0x3280 vxlan_xmit_one+0x14c2/0x4080 vxlan_xmit+0xf61/0x5c00 dev_hard_start_xmit+0xfb/0x510 __dev_queue_xmit+0x7cd/0x32a0 br_dev_queue_push_xmit+0x39d/0x6a0 Use skb_checksum instead of csum_partial who cannot deal with non-linear SKBs. Fixes: 4cb47a8644cc ("tunnels: PMTU discovery support for directly bridged IP packets") Signed-off-by: Antoine Tenart Reviewed-by: Jiri Pirko --- net/ipv4/ip_tunnel_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c index 586b1b3e35b8..80ccd6661aa3 100644 --- a/net/ipv4/ip_tunnel_core.c +++ b/net/ipv4/ip_tunnel_core.c @@ -332,7 +332,7 @@ static int iptunnel_pmtud_build_icmpv6(struct sk_buff *skb, int mtu) }; skb_reset_network_header(skb); - csum = csum_partial(icmp6h, len, 0); + csum = skb_checksum(skb, skb_transport_offset(skb), len, 0); icmp6h->icmp6_cksum = csum_ipv6_magic(&nip6h->saddr, &nip6h->daddr, len, IPPROTO_ICMPV6, csum);