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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 70B75C7618F for ; Mon, 15 Jul 2019 15:12:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3BE3C2054F for ; Mon, 15 Jul 2019 15:12:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563203530; bh=cG+s3l86midlXe3sr5AoOfkzDfj+eldZnIQL42Na/v4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Tbg4vF7avbI1puz74ygMzxDax/TevQqGsptlXFwWAnhcrE5NV6lHYVuGh/GijyavM ErD7Ax34wcHVDS6rdm1sj1y2AEA0hkGiGjaESX5XG5IVHIu14mGaPv4+ij8kbPthao XmSg2+9tNbR6HZSA5Gc/aprtRoiLHJZncQcfwTg8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732299AbfGOPMJ (ORCPT ); Mon, 15 Jul 2019 11:12:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:47040 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732130AbfGONwj (ORCPT ); Mon, 15 Jul 2019 09:52:39 -0400 Received: from sasha-vm.mshome.net (unknown [73.61.17.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 31F55216C4; Mon, 15 Jul 2019 13:52:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563198758; bh=cG+s3l86midlXe3sr5AoOfkzDfj+eldZnIQL42Na/v4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HtAM7W+pr/iuNDbs2iSxx1vuxEIxcc2UIKxD0mSN0l32Q3fEdSmN7P+eRWJKtuNJ1 o34rreTjDH12fyBAMhsWNiRt5SuGGS1a90tFkVExcvOhlvGnhXg1MSfIcPXdUKz9c5 M/9Ovawx6Jkx8XAHC/QaP0zgegPOCtuTr9+4HrS8= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ondrej Mosnacek , Kir Kolyshkin , Paul Moore , Sasha Levin , selinux@vger.kernel.org Subject: [PATCH AUTOSEL 5.2 097/249] selinux: fix empty write to keycreate file Date: Mon, 15 Jul 2019 09:44:22 -0400 Message-Id: <20190715134655.4076-97-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190715134655.4076-1-sashal@kernel.org> References: <20190715134655.4076-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ondrej Mosnacek [ Upstream commit 464c258aa45b09f16aa0f05847ed8895873262d9 ] When sid == 0 (we are resetting keycreate_sid to the default value), we should skip the KEY__CREATE check. Before this patch, doing a zero-sized write to /proc/self/keycreate would check if the current task can create unlabeled keys (which would usually fail with -EACCESS and generate an AVC). Now it skips the check and correctly sets the task's keycreate_sid to 0. Bug report: https://bugzilla.redhat.com/show_bug.cgi?id=1719067 Tested using the reproducer from the report above. Fixes: 4eb582cf1fbd ("[PATCH] keys: add a way to store the appropriate context for newly-created keys") Reported-by: Kir Kolyshkin Signed-off-by: Ondrej Mosnacek Signed-off-by: Paul Moore Signed-off-by: Sasha Levin --- security/selinux/hooks.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 94de51628fdc..3ec7ac70c313 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -6351,11 +6351,12 @@ static int selinux_setprocattr(const char *name, void *value, size_t size) } else if (!strcmp(name, "fscreate")) { tsec->create_sid = sid; } else if (!strcmp(name, "keycreate")) { - error = avc_has_perm(&selinux_state, - mysid, sid, SECCLASS_KEY, KEY__CREATE, - NULL); - if (error) - goto abort_change; + if (sid) { + error = avc_has_perm(&selinux_state, mysid, sid, + SECCLASS_KEY, KEY__CREATE, NULL); + if (error) + goto abort_change; + } tsec->keycreate_sid = sid; } else if (!strcmp(name, "sockcreate")) { tsec->sockcreate_sid = sid; -- 2.20.1