Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753335AbdFST06 (ORCPT + 2 others); Mon, 19 Jun 2017 15:26:58 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:52049 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752910AbdFSSfT (ORCPT ); Mon, 19 Jun 2017 14:35:19 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: OGAWA Hirofumi , Andrew Morton , Linus Torvalds , Willy Tarreau Subject: [PATCH 3.10 171/268] fat: fix using uninitialized fields of fat_inode/fsinfo_inode Date: Mon, 19 Jun 2017 20:31:10 +0200 Message-Id: <1497897167-14556-172-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1497897167-14556-1-git-send-email-w@1wt.eu> References: <1497897167-14556-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: From: OGAWA Hirofumi commit c0d0e351285161a515396b7b1ee53ec9ffd97e3c upstream. Recently fallocate patch was merged and it uses MSDOS_I(inode)->mmu_private at fat_evict_inode(). However, fat_inode/fsinfo_inode that was introduced in past didn't initialize MSDOS_I(inode) properly. With those combinations, it became the cause of accessing random entry in FAT area. Link: http://lkml.kernel.org/r/87pohrj4i8.fsf@mail.parknet.co.jp Signed-off-by: OGAWA Hirofumi Reported-by: Moreno Bartalucci Tested-by: Moreno Bartalucci Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Willy Tarreau --- fs/fat/inode.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/fs/fat/inode.c b/fs/fat/inode.c index 5d4513c..04708fa 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -1193,6 +1193,16 @@ out: return 0; } +static void fat_dummy_inode_init(struct inode *inode) +{ + /* Initialize this dummy inode to work as no-op. */ + MSDOS_I(inode)->mmu_private = 0; + MSDOS_I(inode)->i_start = 0; + MSDOS_I(inode)->i_logstart = 0; + MSDOS_I(inode)->i_attrs = 0; + MSDOS_I(inode)->i_pos = 0; +} + static int fat_read_root(struct inode *inode) { struct super_block *sb = inode->i_sb; @@ -1503,12 +1513,13 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, fat_inode = new_inode(sb); if (!fat_inode) goto out_fail; - MSDOS_I(fat_inode)->i_pos = 0; + fat_dummy_inode_init(fat_inode); sbi->fat_inode = fat_inode; fsinfo_inode = new_inode(sb); if (!fsinfo_inode) goto out_fail; + fat_dummy_inode_init(fsinfo_inode); fsinfo_inode->i_ino = MSDOS_FSINFO_INO; sbi->fsinfo_inode = fsinfo_inode; insert_inode_hash(fsinfo_inode); -- 2.8.0.rc2.1.gbe9624a