From e47776a0a41a14a5634633c96e590827f552c4b5 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 14 Nov 2007 16:58:56 -0800 Subject: 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 Cc: LIOU Payphone Cc: Acked-by: Dave Kleikamp Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ext4/ioctl.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'fs/ext4/ioctl.c') diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index c04c7ccba9e..e7f894bdb42 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -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 */ -- cgit v1.2.3-70-g09d2