From: Suren Baghdasaryan surenb@google.com
Possible buffer overflow when reading next_read_size bytes into tmp buffer after next_read_size was extracted from a previous packet.
cc: Stable stable@vger.kernel.org Signed-off-by: Suren Baghdasaryan surenb@google.com Signed-off-by: Amit Pundir amit.pundir@linaro.org Reviewed-by: Andy Shevchenko andriy.shevchenko@linux.intel.com --- v3: Reset next_read_size to a more readable macro FDP_NCI_I2C_MIN_PAYLOAD instead of 5.
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 c4da50e07bbc..2c5ed2224c5e 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 = FDP_NCI_I2C_MIN_PAYLOAD; + goto flush; + } } else { phy->next_read_size = FDP_NCI_I2C_MIN_PAYLOAD;