Fix dereference of NULL pointer

diff --git a/src/resource.c b/src/resource.c
index 369ac453ac2611fc6bbced76582a588c8178a73d..b525f22873e0acec892296e970ad54c7eff9c3f9 100644 (file)
--- a/src/resource.c
+++ b/src/resource.c
@@ -1038,10 +1038,12 @@ int write_metadata_resource(WIMStruct *w)
                return WIMLIB_ERR_WRITE;
 
        #ifdef ENABLE_SECURITY_DATA
-       subdir_offset = wim_security_data(w)->total_length + root->length + 8;
-       #else
-       subdir_offset = 8 + root->length + 8;
+       struct wim_security_data *sd = wim_security_data(w);
+       if (sd)
+               subdir_offset = sd->total_length + root->length + 8;
+       else
        #endif
+               subdir_offset = 8 + root->length + 8;
        calculate_subdir_offsets(root, &subdir_offset);
        metadata_original_size = subdir_offset;
        buf = MALLOC(metadata_original_size);
@@ -1052,7 +1054,7 @@ int write_metadata_resource(WIMStruct *w)
        }
        #ifdef ENABLE_SECURITY_DATA
        /* Write the security data. */
-       p = write_security_data(wim_security_data(w), buf);
+       p = write_security_data(sd, buf);
        #else
        p = put_u32(buf, 8); /* Total length of security data. */
        p = put_u32(p, 0); /* Number of security data entries. */