From patchwork Fri Jan 22 14:12:24 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 369397 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=ham 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 640F0C433E6 for ; Fri, 22 Jan 2021 14:54:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3A17F239EF for ; Fri, 22 Jan 2021 14:54:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728722AbhAVOyn (ORCPT ); Fri, 22 Jan 2021 09:54:43 -0500 Received: from mail.kernel.org ([198.145.29.99]:40014 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728637AbhAVOXv (ORCPT ); Fri, 22 Jan 2021 09:23:51 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 752DB23A69; Fri, 22 Jan 2021 14:18:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1611325121; bh=QlWNqe83q5yf7zHje8VlVcXxc+H+hS9UUvG/UYN90mA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kAVrYlyZ/vC60Xo5+VoT37eM4CunKyumIM9/2j7sUqidOMKXA1/QsiZK+Q0CaUMBw yjUM0MgDgN/9ivEzoOm2KfBgJvmBNgF+O07s5Pp2Yr3sVQwoWX6fOSHLYEKO5FuiZP En0RkCFEyHb6kHTvZILAkfHEaWizImBBMZcimPy0= 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 5.10 08/43] bpf: Dont leak memory in bpf getsockopt when optlen == 0 Date: Fri, 22 Jan 2021 15:12:24 +0100 Message-Id: <20210122135735.992134571@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210122135735.652681690@linuxfoundation.org> References: <20210122135735.652681690@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@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 @@ -1391,12 +1391,13 @@ 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; }