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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 D4ADBC433E1 for ; Fri, 21 Aug 2020 16:18:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A6B8B22CAF for ; Fri, 21 Aug 2020 16:18:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598026695; bh=0Bpcya60q0A12JUTmhkO1fZ82j89VNCVsocOmSZltpM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=nERmiTjWvMe4ZOIJKB3INdqKiO7jDILDhHAYkUNtPzRFRClpiJ4DTy3/vYjqOQtk4 8SHRveNbskzBd/f3JakUjq+/evFCtJHDP7MQEulDCAflcRg0sV3nbwjf6gpsQsPILu G4chypzhiCF1ut+GjxNCUsOG9iPxkYjQrqLNOZCA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728234AbgHUQSH (ORCPT ); Fri, 21 Aug 2020 12:18:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:46614 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727836AbgHUQPH (ORCPT ); Fri, 21 Aug 2020 12:15:07 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (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 F231320FC3; Fri, 21 Aug 2020 16:15:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598026506; bh=0Bpcya60q0A12JUTmhkO1fZ82j89VNCVsocOmSZltpM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jykAIrvyTIDIEtMSBurqgfCGeQGuMDXsxoa1w5h+VdSaJbmDTTev9BkdpYnl7cl4G 2HRiCeE4kJnimO2HZsKIMCba/wXNJ3LNnMrTqOup4dAl5peBOFWqYOkDRW5zjkooXN 386pT2VvWEdxRKJzbytMHgBQdQQABBtx8cenmkzA= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dehe Gu , Daiyue Zhang , Chao Yu , Jaegeuk Kim , Sasha Levin , linux-f2fs-devel@lists.sourceforge.net Subject: [PATCH AUTOSEL 5.8 34/62] f2fs: remove write attribute of main_blkaddr sysfs node Date: Fri, 21 Aug 2020 12:13:55 -0400 Message-Id: <20200821161423.347071-34-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200821161423.347071-1-sashal@kernel.org> References: <20200821161423.347071-1-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: Dehe Gu [ Upstream commit ffcde4b29a5f20ddca6fe559b48f345818bf1d91 ] Fuzzing main_blkaddr sysfs node will corrupt this field's value, causing kernel panic, remove its write attribute to avoid potential security risk. [Chao Yu: add description] Signed-off-by: Dehe Gu Signed-off-by: Daiyue Zhang Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin --- fs/f2fs/sysfs.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c index e877c59b9fdb4..c5e32ceb94827 100644 --- a/fs/f2fs/sysfs.c +++ b/fs/f2fs/sysfs.c @@ -223,6 +223,13 @@ static ssize_t avg_vblocks_show(struct f2fs_attr *a, } #endif +static ssize_t main_blkaddr_show(struct f2fs_attr *a, + struct f2fs_sb_info *sbi, char *buf) +{ + return snprintf(buf, PAGE_SIZE, "%llu\n", + (unsigned long long)MAIN_BLKADDR(sbi)); +} + static ssize_t f2fs_sbi_show(struct f2fs_attr *a, struct f2fs_sb_info *sbi, char *buf) { @@ -522,7 +529,6 @@ F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_no_gc_sleep_time, no_gc_sleep_time); F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, gc_idle, gc_mode); F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, gc_urgent, gc_mode); F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, reclaim_segments, rec_prefree_segments); -F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, main_blkaddr, main_blkaddr); F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, max_small_discards, max_discards); F2FS_RW_ATTR(DCC_INFO, discard_cmd_control, discard_granularity, discard_granularity); F2FS_RW_ATTR(RESERVED_BLOCKS, f2fs_sb_info, reserved_blocks, reserved_blocks); @@ -565,6 +571,7 @@ F2FS_GENERAL_RO_ATTR(current_reserved_blocks); F2FS_GENERAL_RO_ATTR(unusable); F2FS_GENERAL_RO_ATTR(encoding); F2FS_GENERAL_RO_ATTR(mounted_time_sec); +F2FS_GENERAL_RO_ATTR(main_blkaddr); #ifdef CONFIG_F2FS_STAT_FS F2FS_STAT_ATTR(STAT_INFO, f2fs_stat_info, cp_foreground_calls, cp_count); F2FS_STAT_ATTR(STAT_INFO, f2fs_stat_info, cp_background_calls, bg_cp_count); -- 2.25.1