Btrfs: check for read permission on src file in the clone ioctl
The existing code would have allowed you to clone a file that was
only open for writing
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 2b7dd88..9de6c3a 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1480,12 +1480,17 @@
ret = -EBADF;
goto out_drop_write;
}
+
src = src_file->f_dentry->d_inode;
ret = -EINVAL;
if (src == inode)
goto out_fput;
+ /* the src must be open for reading */
+ if (!(src_file->f_mode & FMODE_READ))
+ goto out_fput;
+
ret = -EISDIR;
if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
goto out_fput;