Commit f04fed1a authored Jan 14, 2016 by Vasily Averin Committed by Sasha Levin Feb 09, 2016

cifs_dbg() outputs an uninitialized buffer in cifs_readdir()



[ Upstream commit 01b9b0b28626db4a47d7f48744d70abca9914ef1 ]

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>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

parent 6b05c541

fs/cifs/readdir.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -845,6 +845,7 @@ 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) {