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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,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 BDD13C433E0 for ; Fri, 22 Jan 2021 18:50:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9031523A60 for ; Fri, 22 Jan 2021 18:50:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730119AbhAVSub (ORCPT ); Fri, 22 Jan 2021 13:50:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:38816 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728552AbhAVOWp (ORCPT ); Fri, 22 Jan 2021 09:22:45 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8015923B6A; Fri, 22 Jan 2021 14:16:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1611324995; bh=NW0j9xkeE8PAdFRoCqVYZ135xURObUv492Mtof7FZ1U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=F++r2/3GM8qBouyClp200Nvs0leP+z1I9u7wZNJF1ZtuWs6/Z7CXb4u0Qo8goploP 6XF+swxNl19hr6l0z9oNXWQLsaXWFs+PxoBrHcWmS1OlwciA0fkxb+w7o+KKlHfqzu 7DmBxnlS8CRsADLj8E1OIGZqe+571VSfB+PoGt2A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Martin KaFai Lau , Stanislav Fomichev , Daniel Borkmann Subject: [PATCH 5.4 10/33] bpf: Dont leak memory in bpf getsockopt when optlen == 0 Date: Fri, 22 Jan 2021 15:12:26 +0100 Message-Id: <20210122135733.995410579@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210122135733.565501039@linuxfoundation.org> References: <20210122135733.565501039@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Stanislav Fomichev commit 4be34f3d0731b38a1b24566b37fbb39500aaf3a2 upstream. optlen == 0 indicates that the kernel should ignore BPF buffer and use the original one from the user. We, however, forget to free the temporary buffer that we've allocated for BPF. Fixes: d8fe449a9c51 ("bpf: Don't return EINVAL from {get,set}sockopt when optlen > PAGE_SIZE") Reported-by: Martin KaFai Lau Signed-off-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20210112162829.775079-1-sdf@google.com Signed-off-by: Greg Kroah-Hartman --- kernel/bpf/cgroup.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -1057,12 +1057,13 @@ int __cgroup_bpf_run_filter_setsockopt(s if (ctx.optlen != 0) { *optlen = ctx.optlen; *kernel_optval = ctx.optval; + /* export and don't free sockopt buf */ + return 0; } } out: - if (ret) - sockopt_free_buf(&ctx); + sockopt_free_buf(&ctx); return ret; } EXPORT_SYMBOL(__cgroup_bpf_run_filter_setsockopt);