From: Ralph Boehme <slow@samba.org>
Date: Tue, 21 Nov 2017 13:28:48 +0000 (+0100)
Subject: s3/loadparm: ensure default service options are not changed
X-Git-Tag: samba-4.6.12~33
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e0a08bdf49d2c3d07f70685bf6bf4404f0e4e119;p=thirdparty%2Fsamba.git

s3/loadparm: ensure default service options are not changed

Rename sDefault to _sDefault and make it const. sDefault is make a copy
of _sDefault in in the initialisation function lp_load_ex().

As we may end up in setup_lp_context() without going through
lp_load_ex(), sDefault may still be uninitialized at that point, so I'm
initializing lp_ctx->sDefault from _sDefault.

Bug: https://bugzilla.samba.org/show_bug.cgi?id=13051

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
(cherry picked from commit ea4e6f95ae5c97e8570b8090ee7e7a577b49a8c3)
---

diff --git a/source3/param/loadparm.c b/source3/param/loadparm.c
index bc82d54fc48..3000ef713d7 100644
--- a/source3/param/loadparm.c
+++ b/source3/param/loadparm.c
@@ -110,7 +110,7 @@ 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;
@@ -956,7 +962,7 @@ static struct loadparm_context *setup_lp_context(TALLOC_CTX *mem_ctx)
 		return NULL;
 	}
 
-	*lp_ctx->sDefault = sDefault;
+	*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;
@@ -3826,6 +3832,7 @@ 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());