libubox: runqueue: fix use-after-free bug

[project/libubox.git] / blobmsg.c

diff --git a/blobmsg.c b/blobmsg.c
index fbc6d2de9135509a955fd55d43a2e0b6be01fe4a..8b9877d7ce9e1cec5d0a37c0488244196d35575f 100644 (file)
--- a/blobmsg.c
+++ b/blobmsg.c
@@ -25,15 +25,25 @@ static const int blob_type[__BLOBMSG_TYPE_LAST] = {
        [BLOBMSG_TYPE_UNSPEC] = BLOB_ATTR_BINARY,
 };
 
-static uint16_t
-blobmsg_namelen(const struct blobmsg_hdr *hdr)
+bool blobmsg_check_attr(const struct blob_attr *attr, bool name)
 {
-       return be16_to_cpu(hdr->namelen);
+       return blobmsg_check_attr_len(attr, name, blob_raw_len(attr));
 }
 
-bool blobmsg_check_attr(const struct blob_attr *attr, bool name)
+static const struct blobmsg_hdr* blobmsg_hdr_from_blob(const struct blob_attr *attr, size_t len)
 {
-       return blobmsg_check_attr_len(attr, name, blob_raw_len(attr));
+       if (len < sizeof(struct blob_attr) + sizeof(struct blobmsg_hdr))
+               return NULL;
+
+       return blob_data(attr);
+}
+
+static bool blobmsg_hdr_valid_namelen(const struct blobmsg_hdr *hdr, size_t len)
+{
+       if (len < sizeof(struct blob_attr) + sizeof(struct blobmsg_hdr) + blobmsg_namelen(hdr) + 1)
+               return false;
+
+       return true;
 }
 
 static bool blobmsg_check_name(const struct blob_attr *attr, size_t len, bool name)
@@ -41,11 +51,17 @@ static bool blobmsg_check_name(const struct blob_attr *attr, size_t len, bool na
        char *limit = (char *) attr + len;
        const struct blobmsg_hdr *hdr;
 
-       hdr = blob_data(attr);
+       hdr = blobmsg_hdr_from_blob(attr, len);
+       if (!hdr)
+               return false;
+
        if (name && !hdr->namelen)
                return false;
 
-       if ((char *) hdr->name + blobmsg_namelen(hdr) > limit)
+       if (name && !blobmsg_hdr_valid_namelen(hdr, len))
+               return false;
+
+       if ((char *) hdr->name + blobmsg_namelen(hdr) + 1 > limit)
                return false;
 
        if (blobmsg_namelen(hdr) > (blob_len(attr) - sizeof(struct blobmsg_hdr)))
@@ -79,9 +95,6 @@ bool blobmsg_check_attr_len(const struct blob_attr *attr, bool name, size_t len)
        size_t data_len;
        int id;
 
-       if (len < sizeof(struct blob_attr))
-               return false;
-
        if (!blobmsg_check_name(attr, len, name))
                return false;
 
@@ -100,12 +113,22 @@ bool blobmsg_check_attr_len(const struct blob_attr *attr, bool name, size_t len)
 }
 
 int blobmsg_check_array(const struct blob_attr *attr, int type)
+{
+       return blobmsg_check_array_len(attr, type, blob_len(attr));
+}
+
+int blobmsg_check_array_len(const struct blob_attr *attr, int type, size_t len)
 {
        struct blob_attr *cur;
        bool name;
-       size_t rem;
        int size = 0;
 
+       if (type > BLOBMSG_TYPE_LAST)
+               return -1;
+
+       if (!blobmsg_check_attr_len(attr, false, len))
+               return -1;
+
        switch (blobmsg_type(attr)) {
        case BLOBMSG_TYPE_TABLE:
                name = true;
@@ -117,11 +140,11 @@ int blobmsg_check_array(const struct blob_attr *attr, int type)
                return -1;
        }
 
-       blobmsg_for_each_attr(cur, attr, rem) {
+       __blobmsg_for_each_attr(cur, attr, len) {
                if (type != BLOBMSG_TYPE_UNSPEC && blobmsg_type(cur) != type)
                        return -1;
 
-               if (!blobmsg_check_attr(cur, name))
+               if (!blobmsg_check_attr_len(cur, name, len))
                        return -1;
 
                size++;
@@ -135,6 +158,11 @@ bool blobmsg_check_attr_list(const struct blob_attr *attr, int type)
        return blobmsg_check_array(attr, type) >= 0;
 }
 
+bool blobmsg_check_attr_list_len(const struct blob_attr *attr, int type, size_t len)
+{
+       return blobmsg_check_array_len(attr, type, len) >= 0;
+}
+
 int blobmsg_parse_array(const struct blobmsg_policy *policy, int policy_len,
                        struct blob_attr **tb, void *data, unsigned int len)
 {
@@ -161,11 +189,10 @@ int blobmsg_parse_array(const struct blobmsg_policy *policy, int policy_len,
        return 0;
 }
 
-
 int blobmsg_parse(const struct blobmsg_policy *policy, int policy_len,
                   struct blob_attr **tb, void *data, unsigned int len)
 {
-       struct blobmsg_hdr *hdr;
+       const struct blobmsg_hdr *hdr;
        struct blob_attr *attr;
        uint8_t *pslen;
        int i;
@@ -182,7 +209,13 @@ int blobmsg_parse(const struct blobmsg_policy *policy, int policy_len,
        }
 
        __blob_for_each_attr(attr, data, len) {
-               hdr = blob_data(attr);
+               hdr = blobmsg_hdr_from_blob(attr, len);
+               if (!hdr)
+                       return -1;
+
+               if (!blobmsg_hdr_valid_namelen(hdr, len))
+                       return -1;
+
                for (i = 0; i < policy_len; i++) {
                        if (!policy[i].name)
                                continue;
@@ -231,7 +264,10 @@ blobmsg_new(struct blob_buf *buf, int type, const char *name, int payload_len, v
        attr->id_len |= be32_to_cpu(BLOB_ATTR_EXTENDED);
        hdr = blob_data(attr);
        hdr->namelen = cpu_to_be16(namelen);
-       strcpy((char *) hdr->name, (const char *)name);
+
+       memcpy(hdr->name, name, namelen);
+       hdr->name[namelen] = '\0';
+
        pad_end = *data = blobmsg_data(attr);
        pad_start = (char *) &hdr->name[namelen];
        if (pad_start < pad_end)
@@ -278,10 +314,17 @@ int blobmsg_vprintf(struct blob_buf *buf, const char *name, const char *format,
        len = vsnprintf(&cbuf, sizeof(cbuf), format, arg2);
        va_end(arg2);
 
+       if (len < 0)
+               return -1;
+
        sbuf = blobmsg_alloc_string_buffer(buf, name, len + 1);
        if (!sbuf)
                return -1;
-       ret = vsprintf(sbuf, format, arg);
+
+       ret = vsnprintf(sbuf, len + 1, format, arg);
+       if (ret < 0)
+               return -1;
+
        blobmsg_add_string_buffer(buf);
 
        return ret;