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>

diff --git a/fs/ext2/ioctl.c b/fs/ext2/ioctl.c
index c2324d5fe4ac149a5672bad13134d4775c815100..320b2cb3d4d22eddf610d7a27d043eeef0437d5e 100644 (file)
--- a/fs/ext2/ioctl.c
+++ b/fs/ext2/ioctl.c
@@ -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;
 
                /*

diff --git a/fs/ext3/ioctl.c b/fs/ext3/ioctl.c
index 4a2a02c95bf94b98fc4534d870f3546a45442c8e..023a070f55f18fac29cfddafa08557085ad6b2fa 100644 (file)
--- a/fs/ext3/ioctl.c
+++ b/fs/ext3/ioctl.c
@@ -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 */

diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index c04c7ccba9e3f140ed5243a6ccdcc58d6afcaa15..e7f894bdb4202359974088ba5c1f14585a43fc03 100644 (file)
--- 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 */

diff --git a/fs/jfs/ioctl.c b/fs/jfs/ioctl.c
index 3c8663bea98ca3bf373f3ea83260b33d67548f3a..dfda12a073e1985fb28b798df2e9088a9a996be4 100644 (file)
--- a/fs/jfs/ioctl.c
+++ b/fs/jfs/ioctl.c
@@ -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;
 

diff --git a/fs/reiserfs/ioctl.c b/fs/reiserfs/ioctl.c
index c438a8f83f26f7ad3412f5fd2f3af69e582ad02d..e0f0f098a523a8d1c3a41099ab76b411989a23a0 100644 (file)
--- a/fs/reiserfs/ioctl.c
+++ b/fs/reiserfs/ioctl.c
@@ -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))