Bluetooth: eir: Fix using strlen with hdev->{dev_name,short_name}

Both dev_name and short_name are not guaranteed to be NULL terminated so
this instead use strnlen and then attempt to determine if the resulting
string needs to be truncated or not.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=216018
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

diff --git a/net/bluetooth/eir.c b/net/bluetooth/eir.c
index 7d77fb0..776d27f 100644 (file)
--- a/net/bluetooth/eir.c
+++ b/net/bluetooth/eir.c
@@ -13,6 +13,20 @@
 
 #define PNP_INFO_SVCLASS_ID            0x1200
 
+static u8 eir_append_name(u8 *eir, u16 eir_len, u8 type, u8 *data, u8 data_len)
+{
+       u8 name[HCI_MAX_SHORT_NAME_LENGTH + 1];
+
+       /* If data is already NULL terminated just pass it directly */
+       if (data[data_len - 1] == '\0')
+               return eir_append_data(eir, eir_len, type, data, data_len);
+
+       memcpy(name, data, HCI_MAX_SHORT_NAME_LENGTH);
+       name[HCI_MAX_SHORT_NAME_LENGTH] = '\0';
+
+       return eir_append_data(eir, eir_len, type, name, sizeof(name));
+}
+
 u8 eir_append_local_name(struct hci_dev *hdev, u8 *ptr, u8 ad_len)
 {
        size_t short_len;
@@ -23,29 +37,26 @@ u8 eir_append_local_name(struct hci_dev *hdev, u8 *ptr, u8 ad_len)
                return ad_len;
 
        /* use complete name if present and fits */
-       complete_len = strlen(hdev->dev_name);
+       complete_len = strnlen(hdev->dev_name, sizeof(hdev->dev_name));
        if (complete_len && complete_len <= HCI_MAX_SHORT_NAME_LENGTH)
-               return eir_append_data(ptr, ad_len, EIR_NAME_COMPLETE,
+               return eir_append_name(ptr, ad_len, EIR_NAME_COMPLETE,
                                       hdev->dev_name, complete_len + 1);
 
        /* use short name if present */
-       short_len = strlen(hdev->short_name);
+       short_len = strnlen(hdev->short_name, sizeof(hdev->short_name));
        if (short_len)
-               return eir_append_data(ptr, ad_len, EIR_NAME_SHORT,
-                                      hdev->short_name, short_len + 1);
+               return eir_append_name(ptr, ad_len, EIR_NAME_SHORT,
+                                      hdev->short_name,
+                                      short_len == HCI_MAX_SHORT_NAME_LENGTH ?
+                                      short_len : short_len + 1);
 
        /* use shortened full name if present, we already know that name
         * is longer then HCI_MAX_SHORT_NAME_LENGTH
         */
-       if (complete_len) {
-               u8 name[HCI_MAX_SHORT_NAME_LENGTH + 1];
-
-               memcpy(name, hdev->dev_name, HCI_MAX_SHORT_NAME_LENGTH);
-               name[HCI_MAX_SHORT_NAME_LENGTH] = '\0';
-
-               return eir_append_data(ptr, ad_len, EIR_NAME_SHORT, name,
-                                      sizeof(name));
-       }
+       if (complete_len)
+               return eir_append_name(ptr, ad_len, EIR_NAME_SHORT,
+                                      hdev->dev_name,
+                                      HCI_MAX_SHORT_NAME_LENGTH);
 
        return ad_len;
 }
@@ -181,7 +192,7 @@ void eir_create(struct hci_dev *hdev, u8 *data)
        u8 *ptr = data;
        size_t name_len;
 
-       name_len = strlen(hdev->dev_name);
+       name_len = strnlen(hdev->dev_name, sizeof(hdev->dev_name));
 
        if (name_len > 0) {
                /* EIR Data type */

diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index ae758ab..ed8cd4a 100644 (file)
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -1082,11 +1082,11 @@ static u16 append_eir_data_to_buf(struct hci_dev *hdev, u8 *eir)
                eir_len = eir_append_le16(eir, eir_len, EIR_APPEARANCE,
                                          hdev->appearance);
 
-       name_len = strlen(hdev->dev_name);
+       name_len = strnlen(hdev->dev_name, sizeof(hdev->dev_name));
        eir_len = eir_append_data(eir, eir_len, EIR_NAME_COMPLETE,
                                  hdev->dev_name, name_len);
 
-       name_len = strlen(hdev->short_name);
+       name_len = strnlen(hdev->short_name, sizeof(hdev->short_name));
        eir_len = eir_append_data(eir, eir_len, EIR_NAME_SHORT,
                                  hdev->short_name, name_len);