diff options
| author | Ben Hutchings <ben.hutchings@codethink.co.uk> | 2018-06-19 11:17:32 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-07-03 11:23:17 +0200 |
| commit | 54ae564b35423f25b763bc9e01b489d9f11c034e (patch) | |
| tree | a10a3892fa8d2d6bea0d48eb301a3478e845cb17 | |
| parent | 2a1b1234d0502237872f6a11016061328528b86d (diff) | |
Input: elan_i2c_smbus - fix more potential stack buffer overflows
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>
| -rw-r--r-- | drivers/input/mouse/elan_i2c.h | 2 | ||||
| -rw-r--r-- | drivers/input/mouse/elan_i2c_core.c | 2 | ||||
| -rw-r--r-- | 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 c0ec26118732..83dd0ce3ad2a 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 2d6481f3e89b..97f6e05cffce 100644 --- 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 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 05b8695a6369..d21bd55f3c42 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; } @@ -470,6 +474,8 @@ 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]); |