From ef8b646183868b2d042fa6cde0eef2a31263ff85 Mon Sep 17 00:00:00 2001 From: Duane Griffin Date: Wed, 7 Jan 2009 18:07:21 -0800 Subject: [PATCH] ext2: tighten restrictions on inode flags At the moment there are few restrictions on which flags may be set on which inodes. Specifically DIRSYNC may only be set on directories and IMMUTABLE and APPEND may not be set on links. Tighten that to disallow TOPDIR being set on non-directories and only NODUMP and NOATIME to be set on non-regular file, non-directories. Introduces a flags masking function which masks flags based on mode and use it during inode creation and when flags are set via the ioctl to facilitate future consistency. Signed-off-by: Duane Griffin Acked-by: Andreas Dilger Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ext2/ialloc.c | 8 ++------ fs/ext2/ioctl.c | 3 +-- include/linux/ext2_fs.h | 17 +++++++++++++++++ 3 files changed, 20 insertions(+), 8 deletions(-) diff --git a/fs/ext2/ialloc.c b/fs/ext2/ialloc.c index b5598e1393d..66321a877e7 100644 --- a/fs/ext2/ialloc.c +++ b/fs/ext2/ialloc.c @@ -565,12 +565,8 @@ got: inode->i_blocks = 0; inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC; memset(ei->i_data, 0, sizeof(ei->i_data)); - ei->i_flags = EXT2_I(dir)->i_flags & EXT2_FL_INHERITED; - if (S_ISLNK(mode)) - ei->i_flags &= ~(EXT2_IMMUTABLE_FL|EXT2_APPEND_FL); - /* dirsync is only applied to directories */ - if (!S_ISDIR(mode)) - ei->i_flags &= ~EXT2_DIRSYNC_FL; + ei->i_flags = + ext2_mask_flags(mode, EXT2_I(dir)->i_flags & EXT2_FL_INHERITED); ei->i_faddr = 0; ei->i_frag_no = 0; ei->i_frag_size = 0; diff --git a/fs/ext2/ioctl.c b/fs/ext2/ioctl.c index de876fa793e..7cb4badef92 100644 --- a/fs/ext2/ioctl.c +++ b/fs/ext2/ioctl.c @@ -50,8 +50,7 @@ long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) goto setflags_out; } - if (!S_ISDIR(inode->i_mode)) - flags &= ~EXT2_DIRSYNC_FL; + flags = ext2_mask_flags(inode->i_mode, flags); mutex_lock(&inode->i_mutex); /* Is it quota file? Do not allow user to mess with it */ diff --git a/include/linux/ext2_fs.h b/include/linux/ext2_fs.h index c3a05181936..121720d74e1 100644 --- a/include/linux/ext2_fs.h +++ b/include/linux/ext2_fs.h @@ -201,6 +201,23 @@ struct ext2_group_desc EXT2_NOCOMP_FL | EXT2_JOURNAL_DATA_FL |\ EXT2_NOTAIL_FL | EXT2_DIRSYNC_FL) +/* Flags that are appropriate for regular files (all but dir-specific ones). */ +#define EXT2_REG_FLMASK (~(EXT2_DIRSYNC_FL | EXT2_TOPDIR_FL)) + +/* Flags that are appropriate for non-directories/regular files. */ +#define EXT2_OTHER_FLMASK (EXT2_NODUMP_FL | EXT2_NOATIME_FL) + +/* Mask out flags that are inappropriate for the given type of inode. */ +static inline __u32 ext2_mask_flags(umode_t mode, __u32 flags) +{ + if (S_ISDIR(mode)) + return flags; + else if (S_ISREG(mode)) + return flags & EXT2_REG_FLMASK; + else + return flags & EXT2_OTHER_FLMASK; +} + /* * ioctl commands */