From: Noel Power <noel.power@suse.com>
Date: Fri, 24 May 2019 14:08:58 +0000 (+0000)
Subject: lib/util: clang: Fix dereference of a null pointer warning
X-Git-Tag: ldb-2.0.5~409
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=e104c01846f6b8bcfb4a3efb269b8b357d17eea6;p=thirdparty%2Fsamba.git

lib/util: clang: Fix dereference of a null pointer warning

Fixes:

lib/util/rbtree.c:170:8: warning: Access to field 'rb_parent_color' results in a dereference of a null pointer (loaded from variable 'other') <--[clang]

We could avoid accessing the NULL pointer but previously the code would
have crashed here. Given this is a rbtree probably better to preserve the
fatal nature of encountering a NULL pointer here while satisfying the static
checker.

Signed-off-by: Noel Power <noel.power@suse.com>
Reviewed-by: Gary Lockyer gary@catalyst.net.nz
---

diff --git a/lib/util/rbtree.c b/lib/util/rbtree.c
index b7add66234f..aa663f49f02 100644
--- a/lib/util/rbtree.c
+++ b/lib/util/rbtree.c
@@ -22,6 +22,7 @@
 
 #include "replace.h"
 #include "rbtree.h"
+#include "fault.h"
 
 #define	RB_RED		0
 #define	RB_BLACK	1
@@ -167,6 +168,12 @@ static void __rb_erase_color(struct rb_node *node, struct rb_node *parent,
 		if (parent->rb_left == node)
 		{
 			other = parent->rb_right;
+			if (other == NULL) {
+				/* we should never get here */
+				smb_panic("corrupted rb tree");
+				/* satisfy static checkers */
+				return;
+			}
 			if (rb_is_red(other))
 			{
 				rb_set_black(other);