Dear Luiz,
Thank you for your patch.
Am 28.05.22 um 02:35 schrieb Luiz Augusto von Dentz:
> From: Luiz Augusto von Dentz <[email protected]>
>
> 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
The *this* does not seem to belong into the sentence.
> string needs to be truncated or not.
>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=216018
> Signed-off-by: Luiz Augusto von Dentz <[email protected]>
Should this be tagged for the stable series?
Kind regards,
Paul
> ---
> net/bluetooth/eir.c | 41 ++++++++++++++++++++++++++---------------
> net/bluetooth/mgmt.c | 4 ++--
> 2 files changed, 28 insertions(+), 17 deletions(-)
>
> diff --git a/net/bluetooth/eir.c b/net/bluetooth/eir.c
> index 7d77fb00c2bf..776d27f7e18d 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;
> }
> @@ -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 cd1b300b9be7..82cc645193f2 100644
> --- 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);
>