On 3 May 2018 at 15:50, Andy Shevchenko
<andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
> On Wed, 2018-05-02 at 23:18 +0530, Amit Pundir wrote:
>> From: Suren Baghdasaryan <surenb@xxxxxxxxxx>
>>
>> Possible buffer overflow when reading next_read_size bytes into
>> tmp buffer after next_read_size was extracted from a previous packet.
>>
>> Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
>> Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx>
>> ---
>> v2:
>> Remove redundant __func__ from dev_dgb().
>>
>> drivers/nfc/fdp/i2c.c | 9 +++++++++
>> 1 file changed, 9 insertions(+)
>>
>> diff --git a/drivers/nfc/fdp/i2c.c b/drivers/nfc/fdp/i2c.c
>> index c4da50e..b80d1ad 100644
>> --- a/drivers/nfc/fdp/i2c.c
>> +++ b/drivers/nfc/fdp/i2c.c
>> @@ -176,6 +176,15 @@ static int fdp_nci_i2c_read(struct fdp_i2c_phy
>> *phy, struct sk_buff **skb)
>> /* Packet that contains a length */
>> if (tmp[0] == 0 && tmp[1] == 0) {
>> phy->next_read_size = (tmp[2] << 8) + tmp[3]
>> + 3;
>> + /*
>> + * Ensure next_read_size does not exceed
>> sizeof(tmp)
>> + * for reading that many bytes during next
>> iteration
>> + */
>> + if (phy->next_read_size >
>> FDP_NCI_I2C_MAX_PAYLOAD) {
>> + dev_dbg(&client->dev, "corrupted
>> packet\n");
>
>> + phy->next_read_size = 5;
>
> Shouldn't be this magic replaced by
>
> phy->next_read_size = FDP_NCI_I2C_MIN_PAYLOAD;
>
> ?
Ack. Fixing it in v3.
Regards,
Amit Pundir
>
>> + goto flush;
>> + }
>> } else {
>> phy->next_read_size =
>> FDP_NCI_I2C_MIN_PAYLOAD;
>>
>
> --
> Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Intel Finland Oy
