CVE-2017-2619: s3/smbd: re-open directory after dptr_CloseDir()

dptr_CloseDir() will close and invalidate the fsp's file descriptor, we
have to reopen it.

Bug: https://bugzilla.samba.org/show_bug.cgi?id=12496

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Uri Simchoni <uri@samba.org>

diff --git a/source3/smbd/smb2_query_directory.c b/source3/smbd/smb2_query_directory.c
index 4b6ca1b8c0abbfcf3b15d4b4ff949d00a599e816..170331003affc58738ade81385ad0c1ae83fa2a7 100644 (file)
--- a/source3/smbd/smb2_query_directory.c
+++ b/source3/smbd/smb2_query_directory.c
@@ -24,6 +24,7 @@
 #include "../libcli/smb/smb_common.h"
 #include "trans2.h"
 #include "../lib/util/tevent_ntstatus.h"
+#include "system/filesys.h"
 
 static struct tevent_req *smbd_smb2_query_directory_send(TALLOC_CTX *mem_ctx,
                                              struct tevent_context *ev,
@@ -322,7 +323,23 @@ static struct tevent_req *smbd_smb2_query_directory_send(TALLOC_CTX *mem_ctx,
        }
 
        if (in_flags & SMB2_CONTINUE_FLAG_REOPEN) {
+               int flags;
+
                dptr_CloseDir(fsp);
+
+               /*
+                * dptr_CloseDir() will close and invalidate the fsp's file
+                * descriptor, we have to reopen it.
+                */
+
+               flags = O_RDONLY;
+#ifdef O_DIRECTORY
+               flags |= O_DIRECTORY;
+#endif
+               status = fd_open(conn, fsp, flags, 0);
+               if (tevent_req_nterror(req, status)) {
+                       return tevent_req_post(req, ev);
+               }
        }
 
        if (!smbreq->posix_pathnames) {