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=-13.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,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 BE0E6C4727C for ; Tue, 29 Sep 2020 12:09:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7A8BE20674 for ; Tue, 29 Sep 2020 12:09:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601381382; bh=f0+XAjM5+5/LhxBHnBVlXukbbef4qgWjJksQ0qln4Fs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=EOTBDdpbJmrsm+xL3RBmDTUWrreK2G1HnPMVpHSwk9Q5rJR8JczICd8ScS4UFFNEK hOc8YOXucO3/LMWLufXM1GbdU1X+xxvUBtk9QnvFK+EnG9XIdF+sYmhuc0FYqpfzTI /BPLTQt1Xvc3gIPsYBOrED8zSPiU1UgVdtQqWPcQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731996AbgI2MJk (ORCPT ); Tue, 29 Sep 2020 08:09:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:58078 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730211AbgI2Lhf (ORCPT ); Tue, 29 Sep 2020 07:37:35 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E608923A9B; Tue, 29 Sep 2020 11:35:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601379332; bh=f0+XAjM5+5/LhxBHnBVlXukbbef4qgWjJksQ0qln4Fs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rI5V2K6gYHpQYI6xqjPjRVBCzbUbRaegAPPuoo+ZUowJesJ43/TeuuKWOhQMrJox1 620lo++2c2It6rNtOL/Ix5MQVzE0/zLA+DxqknJsn/rn+HWEcYPvyQchz7wIxTbMaU vMKae7CT9D8HhFhnkBE3NLlJYIkhgdbYnN+t0Th4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vasily Averin , Stephen Smalley , Paul Moore , Sasha Levin Subject: [PATCH 5.4 115/388] selinux: sel_avc_get_stat_idx should increase position index Date: Tue, 29 Sep 2020 12:57:26 +0200 Message-Id: <20200929110016.042059993@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200929110010.467764689@linuxfoundation.org> References: <20200929110010.467764689@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: Vasily Averin [ Upstream commit 8d269a8e2a8f0bca89022f4ec98de460acb90365 ] If seq_file .next function does not change position index, read after some lseek can generate unexpected output. $ dd if=/sys/fs/selinux/avc/cache_stats # usual output lookups hits misses allocations reclaims frees 817223 810034 7189 7189 6992 7037 1934894 1926896 7998 7998 7632 7683 1322812 1317176 5636 5636 5456 5507 1560571 1551548 9023 9023 9056 9115 0+1 records in 0+1 records out 189 bytes copied, 5,1564e-05 s, 3,7 MB/s $# read after lseek to midle of last line $ dd if=/sys/fs/selinux/avc/cache_stats bs=180 skip=1 dd: /sys/fs/selinux/avc/cache_stats: cannot skip to specified offset 056 9115 <<<< end of last line 1560571 1551548 9023 9023 9056 9115 <<< whole last line once again 0+1 records in 0+1 records out 45 bytes copied, 8,7221e-05 s, 516 kB/s $# read after lseek beyond end of of file $ dd if=/sys/fs/selinux/avc/cache_stats bs=1000 skip=1 dd: /sys/fs/selinux/avc/cache_stats: cannot skip to specified offset 1560571 1551548 9023 9023 9056 9115 <<<< generates whole last line 0+1 records in 0+1 records out 36 bytes copied, 9,0934e-05 s, 396 kB/s https://bugzilla.kernel.org/show_bug.cgi?id=206283 Signed-off-by: Vasily Averin Acked-by: Stephen Smalley Signed-off-by: Paul Moore Signed-off-by: Sasha Levin --- security/selinux/selinuxfs.c | 1 + 1 file changed, 1 insertion(+) diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c index e6c7643c3fc08..e9eaff90cbccd 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -1508,6 +1508,7 @@ static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx) *idx = cpu + 1; return &per_cpu(avc_cache_stats, cpu); } + (*idx)++; return NULL; } -- 2.25.1