@@ -94,6 +94,7 @@ struct mcp2221 {
u8 *rxbuf;
u8 txbuf[64];
int rxbuf_idx;
+ int rxbuf_len;
int status;
u8 cur_i2c_clk_div;
struct gpio_chip *gc;
@@ -286,15 +287,13 @@ static int mcp_i2c_smbus_read(struct mcp2221 *mcp,
total_len = smbus_len;
mcp->rxbuf = smbus_buf;
}
+ mcp->rxbuf_len = total_len;
+ mcp->rxbuf_idx = 0;
spin_unlock_bh(&mcp->raw_event_lock);
ret = mcp_send_data_req_status(mcp, mcp->txbuf, 4);
if (ret)
- return ret;
-
- spin_lock_bh(&mcp->raw_event_lock);
- mcp->rxbuf_idx = 0;
- spin_unlock_bh(&mcp->raw_event_lock);
+ goto out_invalidate_rxbuf;
do {
spin_lock_bh(&mcp->raw_event_lock);
@@ -304,15 +303,22 @@ static int mcp_i2c_smbus_read(struct mcp2221 *mcp,
ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1);
if (ret)
- return ret;
+ goto out_invalidate_rxbuf;
ret = mcp_chk_last_cmd_status(mcp);
if (ret)
- return ret;
+ goto out_invalidate_rxbuf;
usleep_range(980, 1000);
} while (mcp->rxbuf_idx < total_len);
+out_invalidate_rxbuf:
+ spin_lock_bh(&mcp->raw_event_lock);
+ mcp->rxbuf = NULL;
+ mcp->rxbuf_len = 0;
+ mcp->rxbuf_idx = 0;
+ spin_unlock_bh(&mcp->raw_event_lock);
+
return ret;
}
@@ -500,9 +506,15 @@ static int mcp_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
spin_lock_bh(&mcp->raw_event_lock);
mcp->rxbuf_idx = 0;
mcp->rxbuf = data->block;
+ mcp->rxbuf_len = sizeof(data->block);
mcp->txbuf[0] = MCP2221_I2C_GET_DATA;
spin_unlock_bh(&mcp->raw_event_lock);
ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1);
+ spin_lock_bh(&mcp->raw_event_lock);
+ mcp->rxbuf_idx = 0;
+ mcp->rxbuf = NULL;
+ mcp->rxbuf_len = 0;
+ spin_unlock_bh(&mcp->raw_event_lock);
if (ret)
goto exit;
} else {
@@ -525,9 +537,15 @@ static int mcp_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
spin_lock_bh(&mcp->raw_event_lock);
mcp->rxbuf_idx = 0;
mcp->rxbuf = data->block;
+ mcp->rxbuf_len = sizeof(data->block);
mcp->txbuf[0] = MCP2221_I2C_GET_DATA;
spin_unlock_bh(&mcp->raw_event_lock);
ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1);
+ spin_lock_bh(&mcp->raw_event_lock);
+ mcp->rxbuf_idx = 0;
+ mcp->rxbuf = NULL;
+ mcp->rxbuf_len = 0;
+ spin_unlock_bh(&mcp->raw_event_lock);
if (ret)
goto exit;
} else {
@@ -756,6 +774,7 @@ static int mcp2221_raw_event(struct hid_device *hdev,
struct hid_report *report, u8 *data, int size)
{
u8 *buf;
+ int len;
struct mcp2221 *mcp = hid_get_drvdata(hdev);
spin_lock_bh(&mcp->raw_event_lock);
@@ -813,9 +832,15 @@ static int mcp2221_raw_event(struct hid_device *hdev,
break;
}
if (data[2] == MCP2221_I2C_READ_COMPL) {
+ if (mcp->rxbuf == NULL || mcp->rxbuf_idx >= mcp->rxbuf_len)
+ goto out; /* no complete() in this case */
+
buf = mcp->rxbuf;
- memcpy(&buf[mcp->rxbuf_idx], &data[4], data[3]);
- mcp->rxbuf_idx = mcp->rxbuf_idx + data[3];
+ len = data[3];
+ if (len > mcp->rxbuf_len - mcp->rxbuf_idx)
+ len = mcp->rxbuf_len - mcp->rxbuf_idx;
+ memcpy(&buf[mcp->rxbuf_idx], &data[4], len);
+ mcp->rxbuf_idx = mcp->rxbuf_idx + len;
mcp->status = 0;
break;
}
@@ -865,6 +890,7 @@ static int mcp2221_raw_event(struct hid_device *hdev,
complete(&mcp->wait_in_report);
}
+out:
spin_unlock_bh(&mcp->raw_event_lock);
return 1;
In case the MCP2221 driver receives an unexpected read complete report from the device, the data should not be copied to mcp->rxbuf. The pointer might be NULL or even stale, having been set during an earlier transaction. Further, some bounds checking has been added. Signed-off-by: Enrik Berkhan <Enrik.Berkhan@inka.de> --- drivers/hid/hid-mcp2221.c | 44 +++++++++++++++++++++++++++++++-------- 1 file changed, 35 insertions(+), 9 deletions(-)