From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx> 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@xxxxxxxxx> --- net/bluetooth/eir.c | 41 ++++++++++++++++++++++++++--------------- 1 file changed, 26 insertions(+), 15 deletions(-) diff --git a/net/bluetooth/eir.c b/net/bluetooth/eir.c index 7e930f77ecab..4171edee88e4 100644 --- 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; } @@ -168,7 +179,7 @@ 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 */ -- 2.35.1
