4.4-stable review patch. If anyone has any objections, please let me know.
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From: Ben Hutchings ben.hutchings@codethink.co.uk
commit 50fc7b61959af4b95fafce7fe5dd565199e0b61a upstream.
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@vger.kernel.org # 3.19+ Signed-off-by: Ben Hutchings ben.hutchings@codethink.co.uk Reviewed-by: Benjamin Tissoires benjamin.tissoires@redhat.com Signed-off-by: Dmitry Torokhov dmitry.torokhov@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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(-)
--- 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" --- a/drivers/input/mouse/elan_i2c_core.c +++ b/drivers/input/mouse/elan_i2c_core.c @@ -595,7 +595,7 @@ static ssize_t calibrate_store(struct de 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) --- 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 i 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; }
@@ -466,6 +470,8 @@ static int elan_smbus_get_report(struct { 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]);