From 5333e87b5c187c39347786b15f392b897b2f124d Mon Sep 17 00:00:00 2001
From: Ralph Boehme <slow@samba.org>
Date: Tue, 21 Nov 2017 14:28:48 +0100
Subject: [PATCH 1/2] s3/loadparm: ensure default service options are not
 changed

sDefault is initialized from _sDefault in lp_load_ex(). As we may end up
in setup_lp_context() without going through lp_load_ex(), sDefault may
still be uninitialized.

Bug: https://bugzilla.samba.org/show_bug.cgi?id=13051
---
 source3/param/loadparm.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/source3/param/loadparm.c b/source3/param/loadparm.c
index 485d3f75b04..5a60177a626 100644
--- a/source3/param/loadparm.c
+++ b/source3/param/loadparm.c
@@ -111,7 +111,7 @@ static bool defaults_saved = false;
 static struct loadparm_global Globals;
 
 /* This is a default service used to prime a services structure */
-static struct loadparm_service sDefault =
+static const struct loadparm_service _sDefault =
 {
 	.valid = true,
 	.autoloaded = false,
@@ -249,6 +249,12 @@ static struct loadparm_service sDefault =
 	.dummy = ""
 };
 
+/*
+ * This is a copy of the default service structure. Service options in the
+ * global section would otherwise overwrite the initial default values.
+ */
+static struct loadparm_service sDefault;
+
 /* local variables */
 static struct loadparm_service **ServicePtrs = NULL;
 static int iNumServices = 0;
@@ -961,7 +967,13 @@ static struct loadparm_context *setup_lp_context(TALLOC_CTX *mem_ctx)
 		return NULL;
 	}
 
-	lp_ctx->sDefault = &sDefault;
+	lp_ctx->sDefault = talloc_zero(lp_ctx, struct loadparm_service);
+	if (lp_ctx->sDefault == NULL) {
+		DBG_ERR("talloc_zero failed\n");
+		return NULL;
+	}
+
+	*lp_ctx->sDefault = _sDefault;
 	lp_ctx->services = NULL; /* We do not want to access this directly */
 	lp_ctx->bInGlobalSection = bInGlobalSection;
 	lp_ctx->flags = flags_list;
@@ -3851,6 +3863,7 @@ static bool lp_load_ex(const char *pszFname,
 	bInGlobalSection = true;
 	bGlobalOnly = global_only;
 	bAllowIncludeRegistry = allow_include_registry;
+	sDefault = _sDefault;
 
 	lp_ctx = setup_lp_context(talloc_tos());
 
-- 
2.13.6


From 616794173e245ada2c489b7a1afacd414c2520ee Mon Sep 17 00:00:00 2001
From: Ralph Boehme <slow@samba.org>
Date: Tue, 21 Nov 2017 14:34:28 +0100
Subject: [PATCH 2/2] s3/loadparm: don't mark IPC$ as autoloaded

A related problem that affects configuration for the hidden IPC$
share. This share is marked a "autoloaded" and such shares are not
reloaded when requested. That resulted in the tcon to IPC$ still using
encrpytion after running the following sequence of changes:

1. stop Samba
2. set [global] smb encrypt = required
3. start Samba
4. remove [global] smb encrypt = required
5. smbcontrol smbd reload-config
6a bin/smbclient -U slow%x //localhost/raw -c quit, or
6b bin/smbclient -U slow%x -mNT1 //localhost/raw -c ls

In 6a the client simply encrypted packets on the IPC$ tcon. In 6b the
client got a tcon failure with NT_STATUS_ACCESS_DENIED, but silently
ignore the error.

https://bugzilla.samba.org/show_bug.cgi?id=13051
---
 source3/param/loadparm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/source3/param/loadparm.c b/source3/param/loadparm.c
index 5a60177a626..c3f8b8338e5 100644
--- a/source3/param/loadparm.c
+++ b/source3/param/loadparm.c
@@ -1605,7 +1605,7 @@ static bool lp_add_ipc(const char *ipc_name, bool guest_ok)
 	ServicePtrs[i]->guest_ok = guest_ok;
 	ServicePtrs[i]->printable = false;
 	ServicePtrs[i]->browseable = sDefault.browseable;
-	ServicePtrs[i]->autoloaded = true;
+	ServicePtrs[i]->autoloaded = false;
 
 	DEBUG(3, ("adding IPC service\n"));
 
-- 
2.13.6