From 686e8a2489baf6dcbd87de07f37fef07a706dd41 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Tue, 24 Mar 2020 11:33:16 -0700 Subject: Input: goodix - add minimum firmware size check Our goodix_check_cfg_* helpers do things like: int i, raw_cfg_len = cfg->size - 2; ... if (check_sum != cfg->data[raw_cfg_len]) { When cfg->size < 2, this will end up indexing the cfg->data array with a negative value, which will not end well. To fix this this commit adds a new GOODIX_CONFIG_MIN_LENGTH define and adds a minimum size check for firmware-config files using this new define. For consistency this commit also adds a new GOODIX_CONFIG_GT9X_LENGTH for the length used for recent gt9xx and gt1xxx chips, instead of using GOODIX_CONFIG_MAX_LENGTH for this, so that if other length defines get added in the future it will be clear that the MIN and MAX defines should contain the min and max values of all the other defines. Signed-off-by: Hans de Goede Reviewed-by: Bastien Nocera Link: https://lore.kernel.org/r/20200307121505.3707-9-hdegoede@redhat.com Signed-off-by: Dmitry Torokhov --- drivers/input/touchscreen/goodix.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/input/touchscreen/goodix.c b/drivers/input/touchscreen/goodix.c index 7e318938b723..7cca9998ab77 100644 --- a/drivers/input/touchscreen/goodix.c +++ b/drivers/input/touchscreen/goodix.c @@ -39,9 +39,11 @@ #define GOODIX_MAX_CONTACT_SIZE 9 #define GOODIX_MAX_CONTACTS 10 -#define GOODIX_CONFIG_MAX_LENGTH 240 +#define GOODIX_CONFIG_MIN_LENGTH 186 #define GOODIX_CONFIG_911_LENGTH 186 #define GOODIX_CONFIG_967_LENGTH 228 +#define GOODIX_CONFIG_GT9X_LENGTH 240 +#define GOODIX_CONFIG_MAX_LENGTH 240 /* Register defines */ #define GOODIX_REG_COMMAND 0x8040 @@ -109,7 +111,7 @@ static void goodix_calc_cfg_checksum_16(struct goodix_ts_data *ts); static const struct goodix_chip_data gt1x_chip_data = { .config_addr = GOODIX_GT1X_REG_CONFIG_DATA, - .config_len = GOODIX_CONFIG_MAX_LENGTH, + .config_len = GOODIX_CONFIG_GT9X_LENGTH, .check_config = goodix_check_cfg_16, .calc_config_checksum = goodix_calc_cfg_checksum_16, }; @@ -130,7 +132,7 @@ static const struct goodix_chip_data gt967_chip_data = { static const struct goodix_chip_data gt9x_chip_data = { .config_addr = GOODIX_GT9X_REG_CONFIG_DATA, - .config_len = GOODIX_CONFIG_MAX_LENGTH, + .config_len = GOODIX_CONFIG_GT9X_LENGTH, .check_config = goodix_check_cfg_8, .calc_config_checksum = goodix_calc_cfg_checksum_8, }; @@ -525,7 +527,8 @@ static void goodix_calc_cfg_checksum_16(struct goodix_ts_data *ts) static int goodix_check_cfg(struct goodix_ts_data *ts, const struct firmware *cfg) { - if (cfg->size > GOODIX_CONFIG_MAX_LENGTH) { + if (cfg->size < GOODIX_CONFIG_MIN_LENGTH || + cfg->size > GOODIX_CONFIG_MAX_LENGTH) { dev_err(&ts->client->dev, "The length of the config fw is not correct"); return -EINVAL; -- cgit v1.2.3