[PATCH] lib: prevent RTLD_DEEPBIND if run with libasan

[swen]

While at it, prepare lib code to run with ASAN
without the need to set the flag LDB_MODULES_DISABLE_DEEPBIND.

Please review and push if happy.

Cheers Swen
-------------- next part --------------
From 74aed6333e5c4b970ffe55728be8808e9607788b Mon Sep 17 00:00:00 2001
From: Swen Schillig <swen at linux.ibm.com>
Date: Mon, 22 Jul 2019 15:32:46 +0200
Subject: [PATCH] lib: prevent RTLD_DEEPBIND if run with libasan

If run with ASAN sanitizer we cannot use RTLD_DEEPBIND flag for dlopen.

Signed-off-by: Swen Schillig <swen at linux.ibm.com>
---
 lib/ldb/common/ldb_modules.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/lib/ldb/common/ldb_modules.c b/lib/ldb/common/ldb_modules.c
index cc067abdfe0..cef29723b68 100644
--- a/lib/ldb/common/ldb_modules.c
+++ b/lib/ldb/common/ldb_modules.c
@@ -939,7 +939,26 @@ static int ldb_modules_load_path(const char *path, const char *version)
 	int dlopen_flags;
 
 #ifdef RTLD_DEEPBIND
-	bool deepbind_enabled = (getenv("LDB_MODULES_DISABLE_DEEPBIND") == NULL);
+	const char *env_preload = getenv("LD_PRELOAD");
+	const char *env_deepbind = getenv("LDB_MODULES_DISABLE_DEEPBIND");
+	bool deepbind_enabled = true;
+
+	/* Don't do a deepbind if we run with libasan */
+	if (env_preload != NULL && strlen(env_preload) < 1024) {
+		const char *p = strstr(env_preload, "libasan.so");
+		if (p != NULL) {
+			deepbind_enabled = false;
+		}
+	}
+
+	if (env_deepbind != NULL && strlen(env_deepbind) >= 1) {
+		deepbind_enabled = false;
+	}
+
+	if (deepbind_enabled) {
+		dlopen_flags |= RTLD_DEEPBIND;
+	}
+
 #endif
 
 	ret = stat(path, &st);
-- 
2.20.1

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: This is a digitally signed message part
URL: <http://lists.samba.org/pipermail/samba-technical/attachments/20190722/cd7e8dbe/signature.sig>