Forbid user to change file flags on quota files

Forbid user from changing file flags on quota files.  User has no bussiness
in playing with these flags when quota is on.  Furthermore there is a
remote possibility of deadlock due to a lock inversion between quota file's
i_mutex and transaction's start (i_mutex for quota file is locked only when
trasaction is started in quota operations) in ext3 and ext4.

Signed-off-by: Jan Kara <jack@suse.cz>
Cc: LIOU Payphone <lioupayphone@gmail.com>
Cc: <linux-ext4@vger.kernel.org>
Acked-by: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: <reiserfs-dev@namesys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jan Kara 2007-11-14 16:58:56 -08:00 committed by Linus Torvalds
parent 28822f22e1
commit e47776a0a4
5 changed files with 21 additions and 0 deletions

View file

@ -47,6 +47,11 @@ int ext2_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
flags &= ~EXT2_DIRSYNC_FL;
mutex_lock(&inode->i_mutex);
/* Is it quota file? Do not allow user to mess with it */
if (IS_NOQUOTA(inode)) {
mutex_unlock(&inode->i_mutex);
return -EPERM;
}
oldflags = ei->i_flags;
/*

View file

@ -51,6 +51,11 @@ int ext3_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
flags &= ~EXT3_DIRSYNC_FL;
mutex_lock(&inode->i_mutex);
/* Is it quota file? Do not allow user to mess with it */
if (IS_NOQUOTA(inode)) {
mutex_unlock(&inode->i_mutex);
return -EPERM;
}
oldflags = ei->i_flags;
/* The JOURNAL_DATA flag is modifiable only by root */

View file

@ -51,6 +51,11 @@ int ext4_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
flags &= ~EXT4_DIRSYNC_FL;
mutex_lock(&inode->i_mutex);
/* Is it quota file? Do not allow user to mess with it */
if (IS_NOQUOTA(inode)) {
mutex_unlock(&inode->i_mutex);
return -EPERM;
}
oldflags = ei->i_flags;
/* The JOURNAL_DATA flag is modifiable only by root */

View file

@ -79,6 +79,9 @@ int jfs_ioctl(struct inode * inode, struct file * filp, unsigned int cmd,
if (!S_ISDIR(inode->i_mode))
flags &= ~JFS_DIRSYNC_FL;
/* Is it quota file? Do not allow user to mess with it */
if (IS_NOQUOTA(inode))
return -EPERM;
jfs_get_inode_flags(jfs_inode);
oldflags = jfs_inode->mode2;

View file

@ -57,6 +57,9 @@ int reiserfs_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
if (get_user(flags, (int __user *)arg))
return -EFAULT;
/* Is it quota file? Do not allow user to mess with it. */
if (IS_NOQUOTA(inode))
return -EPERM;
if (((flags ^ REISERFS_I(inode)->
i_attrs) & (REISERFS_IMMUTABLE_FL |
REISERFS_APPEND_FL))