From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BA531C04E87 for ; Tue, 21 May 2019 07:53:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 896FF2173C for ; Tue, 21 May 2019 07:53:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=cloudflare.com header.i=@cloudflare.com header.b="fh/ODLpu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726296AbfEUHxa (ORCPT ); Tue, 21 May 2019 03:53:30 -0400 Received: from mail-wm1-f65.google.com ([209.85.128.65]:52017 "EHLO mail-wm1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725790AbfEUHx3 (ORCPT ); Tue, 21 May 2019 03:53:29 -0400 Received: by mail-wm1-f65.google.com with SMTP id c77so1842638wmd.1 for ; Tue, 21 May 2019 00:53:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=1VmwFFsbqJK3+lRSkFVmV7bpMeUDcybN8WqYfoV1sqU=; b=fh/ODLpu818axlZwJplBcIXfLxWCw1MDDaMvyMdY7OZiqk5ux9ysGSuTc8ZdNtHQgw V0ZPljVgnSzv8u80v4/0gyOnK6DaRHzSyKhof2oW3wPv6Y2OtXPKPeDkr8665jqbPBTG fS7TQzE+1r8D0w4xOM3YBV8NXSZs6fQbZ0E08= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=1VmwFFsbqJK3+lRSkFVmV7bpMeUDcybN8WqYfoV1sqU=; b=T2jH+qVvdz6LcgTlUYW//AHMVU8r7q4W0vwm0D0cVmOMyKaJfucubaQAHNyaj5f4LE gsjVBtmY+o2i76RrZE54WEFjIz3iK3RYudqj3UIaOM8ukqqUL06SWipEFyD3JVgFuLh/ D8GwTSDZvNgDHFh8m1lOIX6c7AAv/txhqJhFGNQdidGS49Dy+oHeL2TSgFM27u0xS/kq FntFFHAEG31zqVpAbY17OyaYdBcqtI2xMA/J1u1OUICoOisKI8oO8+57Nb11VXfka15G 9GAEiweJcvxyPFjBOURtpUoZfW+b5Saxp9na4K5JILUneSPwj0fX3RmUDijxRvUNxxCA APTg== X-Gm-Message-State: APjAAAU++xjyYCK3WMizN5rcbfzAz6e+WYSxMWoMyp3g3A4qNL2+ebpO XgR1zgdSKkdkFrfphdSKEIo7aw== X-Google-Smtp-Source: APXvYqylOBVBlr4HUSfame1dJJqGIkr2/KIsfH7YcS0OSUKYlcLzyXSh3YrdTKiWRwlzdHNRuzvaKQ== X-Received: by 2002:a1c:f507:: with SMTP id t7mr2308565wmh.149.1558425207226; Tue, 21 May 2019 00:53:27 -0700 (PDT) Received: from antares.lan (0.1.1.1.3.c.d.b.3.8.f.6.0.5.4.d.f.f.6.2.a.5.a.7.0.b.8.0.1.0.0.2.ip6.arpa. [2001:8b0:7a5a:26ff:d450:6f83:bdc3:1110]) by smtp.gmail.com with ESMTPSA id d198sm2259295wmd.1.2019.05.21.00.53.25 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 21 May 2019 00:53:26 -0700 (PDT) From: Lorenz Bauer To: netdev@vger.kernel.org, bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.com Cc: joe@isovalent.com, Lorenz Bauer Subject: [PATCH bpf] bpf: fix out-of-bounds read in __bpf_skc_lookup Date: Tue, 21 May 2019 08:52:38 +0100 Message-Id: <20190521075238.26803-1-lmb@cloudflare.com> X-Mailer: git-send-email 2.19.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org __bpf_skc_lookup takes a socket tuple and the length of the tuple as an argument. Based on the length, it decides which address family to pass to the helper function sk_lookup. In case of AF_INET6, it fails to verify that the length of the tuple is long enough. sk_lookup may therefore access data past the end of the tuple. Fixes: 6acc9b432e67 ("bpf: Add helper to retrieve socket in BPF") Signed-off-by: Lorenz Bauer --- net/core/filter.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/net/core/filter.c b/net/core/filter.c index 55bfc941d17a..76f1d99640e2 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -5304,7 +5304,13 @@ __bpf_skc_lookup(struct sk_buff *skb, struct bpf_sock_tuple *tuple, u32 len, struct net *net; int sdif; - family = len == sizeof(tuple->ipv4) ? AF_INET : AF_INET6; + if (len == sizeof(tuple->ipv4)) + family = AF_INET; + else if (len == sizeof(tuple->ipv6)) + family = AF_INET6; + else + return NULL; + if (unlikely(family == AF_UNSPEC || flags || !((s32)netns_id < 0 || netns_id <= S32_MAX))) goto out; -- 2.19.1