From: Gary Lockyer <gary@catalyst.net.nz>
Date: Thu, 6 Jun 2019 02:57:45 +0000 (+1200)
Subject: lib tdb: memcmp ubsan warning
X-Git-Tag: ldb-2.0.5~118
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a77fda0cd4b9ec89024c7ac8a3f77797e00f4263;p=thirdparty%2Fsamba.git

lib tdb: memcmp ubsan warning

Fix the ubsan warning

lib/tdb/common/tdb.c:184:9: runtime error: null pointer passed as
argument 2, which is declared to never be null"

memcmp call now guarded by a length check.

memcmp returns zero when called with a zero length parameter.

Signed-off-by: Gary Lockyer <gary@catalyst.net.nz>
Reviewed-by: Noel Power <npower@samba.org>

Autobuild-User(master): Noel Power <npower@samba.org>
Autobuild-Date(master): Mon Jul  1 14:50:54 UTC 2019 on sn-devel-184
---

diff --git a/lib/tdb/common/tdb.c b/lib/tdb/common/tdb.c
index 9c80a36e00a..c56b37be5ca 100644
--- a/lib/tdb/common/tdb.c
+++ b/lib/tdb/common/tdb.c
@@ -180,12 +180,14 @@ static int tdb_update_hash_cmp(TDB_DATA key, TDB_DATA data, void *private_data)
 
 	for (i=0; i<state->num_dbufs; i++) {
 		TDB_DATA dbuf = state->dbufs[i];
-		int ret;
-		ret = memcmp(dptr, dbuf.dptr, dbuf.dsize);
-		if (ret != 0) {
-			return -1;
+		if( dbuf.dsize > 0) {
+			int ret;
+			ret = memcmp(dptr, dbuf.dptr, dbuf.dsize);
+			if (ret != 0) {
+				return -1;
+			}
+			dptr += dbuf.dsize;
 		}
-		dptr += dbuf.dsize;
 	}
 
 	return 0;