Commit e441d54d authored by Chris Mason's avatar Chris Mason

Btrfs: add permission checks to the ioctls

Only root can add/remove devices
Only root can defrag subtrees
Only files open for writing can be defragged
Only files open for writing can be the destination for a clone
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent b34b086c
......@@ -453,6 +453,9 @@ static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg)
if (root->fs_info->sb->s_flags & MS_RDONLY)
return -EROFS;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
if (!vol_args)
......@@ -638,16 +641,24 @@ static int btrfs_ioctl_defrag(struct file *file)
switch (inode->i_mode & S_IFMT) {
case S_IFDIR:
if (!capable(CAP_SYS_ADMIN)) {
ret = -EPERM;
goto out;
}
btrfs_defrag_root(root, 0);
btrfs_defrag_root(root->fs_info->extent_root, 0);
break;
case S_IFREG:
if (!(file->f_mode & FMODE_WRITE)) {
ret = -EINVAL;
goto out;
}
btrfs_defrag_file(file);
break;
}
out:
mnt_drop_write(file->f_path.mnt);
return 0;
return ret;
}
static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
......@@ -655,6 +666,9 @@ static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
struct btrfs_ioctl_vol_args *vol_args;
int ret;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
vol_args = kmalloc(sizeof(*vol_args), GFP_NOFS);
if (!vol_args)
......@@ -677,6 +691,9 @@ static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
struct btrfs_ioctl_vol_args *vol_args;
int ret;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (root->fs_info->sb->s_flags & MS_RDONLY)
return -EROFS;
......@@ -726,6 +743,10 @@ static long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
* they don't overlap)?
*/
/* the destination must be opened for writing */
if (!(file->f_mode & FMODE_WRITE))
return -EINVAL;
ret = mnt_want_write(file->f_path.mnt);
if (ret)
return ret;
......
......@@ -589,6 +589,9 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
int ret = 0;
int len;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
vol = kmalloc(sizeof(*vol), GFP_KERNEL);
if (copy_from_user(vol, (void __user *)arg, sizeof(*vol))) {
ret = -EFAULT;
......
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