disallow creation (of empty files) in read-only mode; reported by

Michal Zalewski, feedback & ok deraadt@

diff --git a/usr.bin/ssh/sftp-server.c b/usr.bin/ssh/sftp-server.c
index 2510d23..42249eb 100644 (file)
--- a/usr.bin/ssh/sftp-server.c
+++ b/usr.bin/ssh/sftp-server.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sftp-server.c,v 1.110 2016/09/12 01:22:38 deraadt Exp $ */
+/* $OpenBSD: sftp-server.c,v 1.111 2017/04/04 00:24:56 djm Exp $ */
 /*
  * Copyright (c) 2000-2004 Markus Friedl.  All rights reserved.
  *
@@ -683,8 +683,8 @@ process_open(u_int32_t id)
        logit("open \"%s\" flags %s mode 0%o",
            name, string_from_portable(pflags), mode);
        if (readonly &&
-           ((flags & O_ACCMODE) == O_WRONLY ||
-           (flags & O_ACCMODE) == O_RDWR)) {
+           ((flags & O_ACCMODE) != O_RDONLY ||
+           (flags & (O_CREAT|O_TRUNC)) != 0)) {
                verbose("Refusing open request in read-only mode");
                status = SSH2_FX_PERMISSION_DENIED;
        } else {