On Thu, 2007-11-01 at 10:55 -0700, akpm@xxxxxxxxxxxxxxxxxxxx wrote: > The patch titled > Forbid user to change file flags on quota files > has been added to the -mm tree. Its filename is > forbid-user-to-change-file-flags-on-quota-files.patch > > *** Remember to use Documentation/SubmitChecklist when testing your code *** > > See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find > out what to do about this > > ------------------------------------------------------ > Subject: Forbid user to change file flags on quota files > From: Jan Kara <jack@xxxxxxx> > > 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. This looks reasonable. > > Signed-off-by: Jan Kara <jack@xxxxxxx> > Cc: LIOU Payphone <lioupayphone@xxxxxxxxx> > Cc: <linux-ext4@xxxxxxxxxxxxxxx> Acked-by: Dave Kleikamp <shaggy@xxxxxxxxxxxxxxxxxx> > Cc: <reiserfs-dev@xxxxxxxxxxx> > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > --- > > fs/ext2/ioctl.c | 5 +++++ > fs/ext3/ioctl.c | 5 +++++ > fs/ext4/ioctl.c | 5 +++++ > fs/jfs/ioctl.c | 3 +++ > fs/reiserfs/ioctl.c | 3 +++ > 5 files changed, 21 insertions(+) > > diff -puN fs/ext2/ioctl.c~forbid-user-to-change-file-flags-on-quota-files fs/ext2/ioctl.c > --- a/fs/ext2/ioctl.c~forbid-user-to-change-file-flags-on-quota-files > +++ a/fs/ext2/ioctl.c > @@ -47,6 +47,11 @@ int ext2_ioctl (struct inode * inode, st > flags &= ~EXT2_DIRSYNC_FL; > > mutex_lock(&inode->i_mutex); > + /* Is it quota file? Don't allow user mess with it */ > + if (IS_NOQUOTA(inode)) { > + mutex_unlock(&inode->i_mutex); > + return -EPERM; > + } > oldflags = ei->i_flags; > > /* > diff -puN fs/ext3/ioctl.c~forbid-user-to-change-file-flags-on-quota-files fs/ext3/ioctl.c > --- a/fs/ext3/ioctl.c~forbid-user-to-change-file-flags-on-quota-files > +++ a/fs/ext3/ioctl.c > @@ -51,6 +51,11 @@ int ext3_ioctl (struct inode * inode, st > flags &= ~EXT3_DIRSYNC_FL; > > mutex_lock(&inode->i_mutex); > + /* Is it quota file? Don't allow user 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 */ > diff -puN fs/ext4/ioctl.c~forbid-user-to-change-file-flags-on-quota-files fs/ext4/ioctl.c > --- a/fs/ext4/ioctl.c~forbid-user-to-change-file-flags-on-quota-files > +++ a/fs/ext4/ioctl.c > @@ -51,6 +51,11 @@ int ext4_ioctl (struct inode * inode, st > flags &= ~EXT4_DIRSYNC_FL; > > mutex_lock(&inode->i_mutex); > + /* Is it quota file? Don't allow user 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 */ > diff -puN fs/jfs/ioctl.c~forbid-user-to-change-file-flags-on-quota-files fs/jfs/ioctl.c > --- a/fs/jfs/ioctl.c~forbid-user-to-change-file-flags-on-quota-files > +++ a/fs/jfs/ioctl.c > @@ -79,6 +79,9 @@ int jfs_ioctl(struct inode * inode, stru > if (!S_ISDIR(inode->i_mode)) > flags &= ~JFS_DIRSYNC_FL; > > + /* Is it quota file? Don't allow user mess with it */ > + if (IS_NOQUOTA(inode)) > + return -EPERM; > jfs_get_inode_flags(jfs_inode); > oldflags = jfs_inode->mode2; > > diff -puN fs/reiserfs/ioctl.c~forbid-user-to-change-file-flags-on-quota-files fs/reiserfs/ioctl.c > --- a/fs/reiserfs/ioctl.c~forbid-user-to-change-file-flags-on-quota-files > +++ a/fs/reiserfs/ioctl.c > @@ -57,6 +57,9 @@ int reiserfs_ioctl(struct inode *inode, > if (get_user(flags, (int __user *)arg)) > return -EFAULT; > > + /* Is it quota file? Don't allow user mess with it. */ > + if (IS_NOQUOTA(inode)) > + return -EPERM; > if (((flags ^ REISERFS_I(inode)-> > i_attrs) & (REISERFS_IMMUTABLE_FL | > REISERFS_APPEND_FL)) > _ > -- David Kleikamp IBM Linux Technology Center - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
