waf: Build nmbd with -Wno-error=stringop-overflow

We use strlcpy() which has been added to glibc recently. This means we
also get fortification for strlcpy() now:

source3/nmbd/nmbd_browsesync.c: In function ‘find_domain_master_name_query_success’:
source3/nmbd/nmbd_browsesync.c:337:9: warning: ‘strlcpy’ writing 257 bytes into a
region of size 16 overflows the destination [-Wstringop-overflow=]
  337 |         strlcpy(userdata->data, work->work_group, size - sizeof(*userdata));
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We allocate memory for the userdata struct + fstring. However the data
pointer we use only is 16 bytes. Also nowadays you would use offsetof()
for the allocation calculation, but it only works correctly on newer
compilers like gcc > 7. We could make use of it in future after CentOS 7
is gone.

As we don't want to touch nmbd anymore, just silence the warnings.

Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

diff --git a/buildtools/wafsamba/samba_autoconf.py b/buildtools/wafsamba/samba_autoconf.py
index 8541d003e2a5b2274c5c31702a7ce70fe905d7eb..7cebcca40c528359e1066a98c1768a37abbc37f0 100644 (file)
--- a/buildtools/wafsamba/samba_autoconf.py
+++ b/buildtools/wafsamba/samba_autoconf.py
@@ -817,6 +817,9 @@ int main(void) {
         if CHECK_CFLAGS(conf, ["-Wno-error=array-bounds"]):
             conf.define('HAVE_WNO_ERROR_ARRAY_BOUNDS', 1)
 
+        if CHECK_CFLAGS(conf, ["-Wno-error=stringop-overflow"]):
+            conf.define('HAVE_WNO_ERROR_STRINGOP_OVERFLOW', 1)
+
         if not Options.options.disable_warnings_as_errors:
             conf.ADD_NAMED_CFLAGS('PICKY_CFLAGS', '-Werror -Wno-error=deprecated-declarations', testflags=True)
             conf.ADD_NAMED_CFLAGS('PICKY_CFLAGS', '-Wno-error=tautological-compare', testflags=True)

diff --git a/source3/nmbd/wscript_build b/source3/nmbd/wscript_build
index 22057dfb6b0e3dfe7bf208eb470e534cbb4b4af3..399cdb441888e124ea52a8b736c7bd3fd4dcf0f8 100644 (file)
--- a/source3/nmbd/wscript_build
+++ b/source3/nmbd/wscript_build
@@ -1,5 +1,9 @@
 #!/usr/bin/env python
 
+nmbd_cflags = ''
+if bld.CONFIG_SET('HAVE_WNO_ERROR_STRINGOP_OVERFLOW'):
+    nmbd_cflags = '-Wno-error=stringop-overflow'
+
 bld.SAMBA3_BINARY('nmbd',
                  source='''
                  asyncdns.c
@@ -30,6 +34,7 @@ bld.SAMBA3_BINARY('nmbd',
                  nmbd_workgroupdb.c
                  nmbd_synclists.c
                  ''',
+                 cflags=nmbd_cflags,
                  deps='''
                  talloc
                  tevent