configfs: Return -EFBIG from configfs_write_bin_file.

commit 42857cf512cb34c2c8cb50f1e766689d979d64e0 upstream.

The check for writing more than cb_max_size bytes does not 'goto out' so
it is a no-op which allows users to vmalloc an arbitrary amount.

Fixes: 03607ace807b ("configfs: implement binary attributes")
Signed-off-by: Phil Turnbull <phil.turnbull@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/configfs/file.c b/fs/configfs/file.c
index bbc1252a59f5f1431ee779e16780f19a5f47a5d8..2ddfa05d71f52b66fd4f8f27fae0d96794f39461 100644 (file)
--- a/fs/configfs/file.c
+++ b/fs/configfs/file.c
@@ -333,6 +333,7 @@ configfs_write_bin_file(struct file *file, const char __user *buf,
                if (bin_attr->cb_max_size &&
                        *ppos + count > bin_attr->cb_max_size) {
                        len = -EFBIG;
+                       goto out;
                }
 
                tbuf = vmalloc(*ppos + count);