From b1c823dc8c2824ec89921601d8e5e95f6d18fca8 Mon Sep 17 00:00:00 2001
From: Jeremy Allison <jra@samba.org>
Date: Tue, 22 Sep 2015 18:02:53 -0700
Subject: [PATCH] s3: smbd: Fix mkdir race condition.

Found by Max of LoadDynamix <adx.forum@gmail.com>

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11486

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>
---
 source3/smbd/open.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/source3/smbd/open.c b/source3/smbd/open.c
index 809fa352dfc..162e8347b94 100644
--- a/source3/smbd/open.c
+++ b/source3/smbd/open.c
@@ -3488,6 +3488,25 @@ static NTSTATUS open_directory(connection_struct *conn,
 							nt_errstr(status)));
 						return status;
 					}
+
+					/*
+					 * If mkdir_internal() returned
+					 * NT_STATUS_OBJECT_NAME_COLLISION
+					 * we still must lstat the path.
+					 */
+
+					if (SMB_VFS_LSTAT(conn, smb_dname)
+							== -1) {
+						DEBUG(2, ("Could not stat "
+							"directory '%s' just "
+							"opened: %s\n",
+							smb_fname_str_dbg(
+								smb_dname),
+							strerror(errno)));
+						return map_nt_error_from_unix(
+								errno);
+					}
+
 					info = FILE_WAS_OPENED;
 				}
 			}