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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CA794C77B75 for ; Mon, 8 May 2023 10:09:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234146AbjEHKJx (ORCPT ); Mon, 8 May 2023 06:09:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37840 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234153AbjEHKJt (ORCPT ); Mon, 8 May 2023 06:09:49 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CCB6F3292B for ; Mon, 8 May 2023 03:09:47 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 5EFE4623A8 for ; Mon, 8 May 2023 10:09:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 73BC7C433D2; Mon, 8 May 2023 10:09:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1683540586; bh=LMIRdMaa3fH7lGEg6C1PbLcnWMZuqYKIUZ5Rmn4b2hc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KxM+QEk1yGUhTvuRrzGNCrOLZSOaWGnFNnkou6FsmRIUtuRMSR2vq/Cn9xjaP80dr ulkhIhflpuE9Zv33oh+xJH+Wn40f3nniiHuxFq5vkkV6zlnVR3jJumdrfPHISXoQ8S OrIRxXYnWlIzcI65qYYd78jILSMXnjFZye4dY+hw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Martin KaFai Lau , Stanislav Fomichev , Daniel Borkmann , Sasha Levin Subject: [PATCH 6.1 388/611] bpf: Dont EFAULT for getsockopt with optval=NULL Date: Mon, 8 May 2023 11:43:50 +0200 Message-Id: <20230508094434.909838193@linuxfoundation.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230508094421.513073170@linuxfoundation.org> References: <20230508094421.513073170@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Stanislav Fomichev [ Upstream commit 00e74ae0863827d944e36e56a4ce1e77e50edb91 ] Some socket options do getsockopt with optval=NULL to estimate the size of the final buffer (which is returned via optlen). This breaks BPF getsockopt assumptions about permitted optval buffer size. Let's enforce these assumptions only when non-NULL optval is provided. Fixes: 0d01da6afc54 ("bpf: implement getsockopt and setsockopt hooks") Reported-by: Martin KaFai Lau Signed-off-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/ZD7Js4fj5YyI2oLd@google.com/T/#mb68daf700f87a9244a15d01d00c3f0e5b08f49f7 Link: https://lore.kernel.org/bpf/20230418225343.553806-2-sdf@google.com Signed-off-by: Sasha Levin --- kernel/bpf/cgroup.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index bf2fdb33fb313..819f011f0a9cd 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -1921,14 +1921,17 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level, if (ret < 0) goto out; - if (ctx.optlen > max_optlen || ctx.optlen < 0) { + if (optval && (ctx.optlen > max_optlen || ctx.optlen < 0)) { ret = -EFAULT; goto out; } if (ctx.optlen != 0) { - if (copy_to_user(optval, ctx.optval, ctx.optlen) || - put_user(ctx.optlen, optlen)) { + if (optval && copy_to_user(optval, ctx.optval, ctx.optlen)) { + ret = -EFAULT; + goto out; + } + if (put_user(ctx.optlen, optlen)) { ret = -EFAULT; goto out; } -- 2.39.2