Btrfs: Fix BTRFS_IOC_SUBVOL_SETFLAGS ioctl
- Check user-specified flags correctly
- Check the inode owership
- Search root item in root tree but not fs tree
Reported-by: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index be2d4f6..5fdb2ab 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1071,12 +1071,15 @@
if (copy_from_user(&flags, arg, sizeof(flags)))
return -EFAULT;
- if (flags & ~BTRFS_SUBVOL_CREATE_ASYNC)
+ if (flags & BTRFS_SUBVOL_CREATE_ASYNC)
return -EINVAL;
if (flags & ~BTRFS_SUBVOL_RDONLY)
return -EOPNOTSUPP;
+ if (!is_owner_or_cap(inode))
+ return -EACCES;
+
down_write(&root->fs_info->subvol_sem);
/* nothing to do */
@@ -1097,7 +1100,7 @@
goto out_reset;
}
- ret = btrfs_update_root(trans, root,
+ ret = btrfs_update_root(trans, root->fs_info->tree_root,
&root->root_key, &root->root_item);
btrfs_commit_transaction(trans, root);