Input: synaptics-rmi4 - do not consume more data than we have (F11, F12)

Currently, rmi_f11_attention() and rmi_f12_attention() functions update
the attn_data data pointer and size based on the size of the expected
size of the attention data. However, if the actual valid data in the
attn buffer is less then the expected value then the updated data
pointer will point to memory beyond the end of the attn buffer. Using
the calculated valid_bytes instead will prevent this from happening.

Signed-off-by: Andrew Duggan <aduggan@synaptics.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20191025002527.3189-3-aduggan@synaptics.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/rmi4/rmi_f11.c b/drivers/input/rmi4/rmi_f11.c
index f28a715..26c2393 100644 (file)
--- a/drivers/input/rmi4/rmi_f11.c
+++ b/drivers/input/rmi4/rmi_f11.c
@@ -1284,8 +1284,8 @@ static irqreturn_t rmi_f11_attention(int irq, void *ctx)
                        valid_bytes = f11->sensor.attn_size;
                memcpy(f11->sensor.data_pkt, drvdata->attn_data.data,
                        valid_bytes);
-               drvdata->attn_data.data += f11->sensor.attn_size;
-               drvdata->attn_data.size -= f11->sensor.attn_size;
+               drvdata->attn_data.data += valid_bytes;
+               drvdata->attn_data.size -= valid_bytes;
        } else {
                error = rmi_read_block(rmi_dev,
                                data_base_addr, f11->sensor.data_pkt,

diff --git a/drivers/input/rmi4/rmi_f12.c b/drivers/input/rmi4/rmi_f12.c
index 734077f..7e97944 100644 (file)
--- a/drivers/input/rmi4/rmi_f12.c
+++ b/drivers/input/rmi4/rmi_f12.c
@@ -212,8 +212,8 @@ static irqreturn_t rmi_f12_attention(int irq, void *ctx)
                        valid_bytes = sensor->attn_size;
                memcpy(sensor->data_pkt, drvdata->attn_data.data,
                        valid_bytes);
-               drvdata->attn_data.data += sensor->attn_size;
-               drvdata->attn_data.size -= sensor->attn_size;
+               drvdata->attn_data.data += valid_bytes;
+               drvdata->attn_data.size -= valid_bytes;
        } else {
                retval = rmi_read_block(rmi_dev, f12->data_addr,
                                        sensor->data_pkt, sensor->pkt_size);