From patchwork Tue Sep 29 10:58:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 291160 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=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 0FE4FC4727C for ; Tue, 29 Sep 2020 11:30:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C48BD23A7B for ; Tue, 29 Sep 2020 11:30:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601379037; bh=i1ZgjExRvDCjhGcCJkiP8I89j+dferq7go6VHY189IY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=tLD/L1vVZACc2nOAL9tRLJ/GzeRvbc/o3xFBZ4ka8t7i8U+cT/guPKf8RsAsP7ar1 vpvxfbyj6g+T6pEo+oFRmYGuKGHILAbqoi9gmMmCyPt57dx+7XkC2VHuP9EA8EtUvZ 0St89RggdcXTWUjBY3O1buitPY6HcA8mmbRLOeqY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729134AbgI2La2 (ORCPT ); Tue, 29 Sep 2020 07:30:28 -0400 Received: from mail.kernel.org ([198.145.29.99]:41878 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728295AbgI2L3X (ORCPT ); Tue, 29 Sep 2020 07:29:23 -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 3C14723A5D; Tue, 29 Sep 2020 11:23:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601378627; bh=i1ZgjExRvDCjhGcCJkiP8I89j+dferq7go6VHY189IY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aoI5z0xdFcE8PW3akf13/z358AKDHC2Jk5ZT29PYDHWfW4DxrCH9uSK88eJ57y2+q 75t1/7oKCDurIQLwmOXUwTm6gv/onr+yJYrJRupT5BCxlRlUsgoixS7tz7PZRVoQ7l FKktzsYBnsJew6ckuwPfDX4raQ6EcIZpmvubzc58= 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 4.19 074/245] selinux: sel_avc_get_stat_idx should increase position index Date: Tue, 29 Sep 2020 12:58:45 +0200 Message-Id: <20200929105950.598465758@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200929105946.978650816@linuxfoundation.org> References: <20200929105946.978650816@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@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 f3a5a138a096d..60b3f16bb5c7b 100644 --- a/security/selinux/selinuxfs.c +++ b/security/selinux/selinuxfs.c @@ -1509,6 +1509,7 @@ 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; }