cifs_dbg() outputs an uninitialized buffer in cifs_readdir()

In some cases tmp_bug can be not filled in cifs_filldir and stay uninitialized,
therefore its printk with "%s" modifier can leak content of kernelspace memory.
If old content of this buffer does not contain '\0' access bejond end of
allocated object can crash the host.

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Steve French <sfrench@localhost.localdomain>
CC: Stable <stable@vger.kernel.org>
This commit is contained in:
Vasily Averin 2016-01-14 13:41:14 +03:00 committed by Steve French
parent 820962dc70
commit 01b9b0b286

View File

@ -847,6 +847,7 @@ int cifs_readdir(struct file *file, struct dir_context *ctx)
* if buggy server returns . and .. late do we want to
* check for that here?
*/
*tmp_buf = 0;
rc = cifs_filldir(current_entry, file, ctx,
tmp_buf, max_len);
if (rc) {