fix segfault when passed blobmsg attr is NULL

[project/libubox.git] / blobmsg.h

diff --git a/blobmsg.h b/blobmsg.h
index 797729870fbd449b057315dedf54b07032fe4fca..b06ef597d8c6d836d9eecb9227e6825576ada13e 100644 (file)
--- a/blobmsg.h
+++ b/blobmsg.h
@@ -71,8 +71,14 @@ static inline int blobmsg_type(const struct blob_attr *attr)
 
 static inline void *blobmsg_data(const struct blob_attr *attr)
 {
-       struct blobmsg_hdr *hdr = (struct blobmsg_hdr *) blob_data(attr);
-       char *data = (char *) blob_data(attr);
+       struct blobmsg_hdr *hdr;
+       char *data;
+
+       if (!attr)
+               return NULL;
+
+       hdr = (struct blobmsg_hdr *) blob_data(attr);
+       data = (char *) blob_data(attr);
 
        if (blob_is_extended(attr))
                data += blobmsg_hdrlen(be16_to_cpu(hdr->namelen));
@@ -84,6 +90,9 @@ static inline int blobmsg_data_len(const struct blob_attr *attr)
 {
        uint8_t *start, *end;
 
+       if (!attr)
+               return 0;
+
        start = (uint8_t *) blob_data(attr);
        end = (uint8_t *) blobmsg_data(attr);