Commit 40f7090bb1b4 ("Input: elan_i2c_smbus - fix corrupted stack")
fixed most of the functions using i2c_smbus_read_block_data() to
allocate a buffer with the maximum block size. However three
functions were left unchanged:
* In elan_smbus_initialize(), increase the buffer size in the same
way.
* In elan_smbus_calibrate_result(), the buffer is provided by the
caller (calibrate_store()), so introduce a bounce buffer. Also
name the result buffer size.
* In elan_smbus_get_report(), the buffer is provided by the caller
but happens to be the right length. Add a compile-time assertion
to ensure this remains the case.
Cc: <stable@xxxxxxxxxxxxxxx> # 3.19+
Signed-off-by: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx>
---
This is compile-tested only.
Ben.
drivers/input/mouse/elan_i2c.h | 2 ++
drivers/input/mouse/elan_i2c_core.c | 2 +-
drivers/input/mouse/elan_i2c_smbus.c | 10 ++++++++--
3 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/drivers/input/mouse/elan_i2c.h b/drivers/input/mouse/elan_i2c.h
index 599544c1a91c..243e0fa6e3e3 100644
--- a/drivers/input/mouse/elan_i2c.h
+++ b/drivers/input/mouse/elan_i2c.h
@@ -27,6 +27,8 @@
#define ETP_DISABLE_POWER 0x0001
#define ETP_PRESSURE_OFFSET 25
+#define ETP_CALIBRATE_MAX_LEN 3
+
/* IAP Firmware handling */
#define ETP_PRODUCT_ID_FORMAT_STRING "%d.0"
#define ETP_FW_NAME "elan_i2c_" ETP_PRODUCT_ID_FORMAT_STRING ".bin"
diff --git a/drivers/input/mouse/elan_i2c_core.c b/drivers/input/mouse/elan_i2c_core.c
index 75e757520ef0..d5f74dd7e23b 100644
--- a/drivers/input/mouse/elan_i2c_core.c
+++ b/drivers/input/mouse/elan_i2c_core.c
@@ -610,7 +610,7 @@ static ssize_t calibrate_store(struct device *dev,
int tries = 20;
int retval;
int error;
- u8 val[3];
+ u8 val[ETP_CALIBRATE_MAX_LEN];
retval = mutex_lock_interruptible(&data->sysfs_mutex);
if (retval)
diff --git a/drivers/input/mouse/elan_i2c_smbus.c b/drivers/input/mouse/elan_i2c_smbus.c
index cfcb32559925..c060d270bc4d 100644
--- a/drivers/input/mouse/elan_i2c_smbus.c
+++ b/drivers/input/mouse/elan_i2c_smbus.c
@@ -56,7 +56,7 @@
static int elan_smbus_initialize(struct i2c_client *client)
{
u8 check[ETP_SMBUS_HELLOPACKET_LEN] = { 0x55, 0x55, 0x55, 0x55, 0x55 };
- u8 values[ETP_SMBUS_HELLOPACKET_LEN] = { 0, 0, 0, 0, 0 };
+ u8 values[I2C_SMBUS_BLOCK_MAX] = {0};
int len, error;
/* Get hello packet */
@@ -117,12 +117,16 @@ static int elan_smbus_calibrate(struct i2c_client *client)
static int elan_smbus_calibrate_result(struct i2c_client *client, u8 *val)
{
int error;
+ u8 buf[I2C_SMBUS_BLOCK_MAX] = {0};
+
+ BUILD_BUG_ON(ETP_CALIBRATE_MAX_LEN > sizeof(buf));
error = i2c_smbus_read_block_data(client,
- ETP_SMBUS_CALIBRATE_QUERY, val);
+ ETP_SMBUS_CALIBRATE_QUERY, buf);
if (error < 0)
return error;
+ memcpy(val, buf, ETP_CALIBRATE_MAX_LEN);
return 0;
}
@@ -472,6 +476,8 @@ static int elan_smbus_get_report(struct i2c_client *client, u8 *report)
{
int len;
+ BUILD_BUG_ON(I2C_SMBUS_BLOCK_MAX > ETP_SMBUS_REPORT_LEN);
+
len = i2c_smbus_read_block_data(client,
ETP_SMBUS_PACKET_QUERY,
&report[ETP_SMBUS_REPORT_OFFSET]);
--
Ben Hutchings, Software Developer Codethink Ltd
https://www.codethink.co.uk/ Dale House, 35 Dale Street
Manchester, M1 2HF, United Kingdom
