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Commit a4891f10 authored by Nick Dyer's avatar Nick Dyer Committed by Dmitry Torokhov
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Input: atmel_mxt_ts - zero terminate config firmware file 



We use sscanf to parse the configuration file, so it's necessary to zero
terminate the configuration otherwise a truncated file can cause the
parser to run off into uninitialised memory.

Signed-off-by: default avatarNick Dyer <nick.dyer@itdev.co.uk>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent f865df73

drivers/input/touchscreen/atmel_mxt_ts.c

+24 −10
Original line number Diff line number Diff line
@@ -279,7 +279,7 @@ enum mxt_suspend_mode { 


/* Config update context */

struct mxt_cfg {

	const u8 *raw;

	u8 *raw;

	size_t raw_size;

	off_t raw_pos;
@@ -1451,14 +1451,19 @@ static int mxt_update_cfg(struct mxt_data *data, const struct firmware *fw) 
	u32 info_crc, config_crc, calculated_crc;

	u16 crc_start = 0;



	cfg.raw = fw->data;

	/* Make zero terminated copy of the OBP_RAW file */

	cfg.raw = kmemdup_nul(fw->data, fw->size, GFP_KERNEL);

	if (!cfg.raw)

		return -ENOMEM;



	cfg.raw_size = fw->size;



	mxt_update_crc(data, MXT_COMMAND_REPORTALL, 1);



	if (strncmp(cfg.raw, MXT_CFG_MAGIC, strlen(MXT_CFG_MAGIC))) {

		dev_err(dev, "Unrecognised config file\n");

		return -EINVAL;

		ret = -EINVAL;

		goto release_raw;

	}



	cfg.raw_pos = strlen(MXT_CFG_MAGIC);
@@ -1470,7 +1475,8 @@ static int mxt_update_cfg(struct mxt_data *data, const struct firmware *fw) 
			     &offset);

		if (ret != 1) {

			dev_err(dev, "Bad format\n");

			return -EINVAL;

			ret = -EINVAL;

			goto release_raw;

		}



		cfg.raw_pos += offset;
@@ -1478,26 +1484,30 @@ static int mxt_update_cfg(struct mxt_data *data, const struct firmware *fw) 


	if (cfg.info.family_id != data->info->family_id) {

		dev_err(dev, "Family ID mismatch!\n");

		return -EINVAL;

		ret = -EINVAL;

		goto release_raw;

	}



	if (cfg.info.variant_id != data->info->variant_id) {

		dev_err(dev, "Variant ID mismatch!\n");

		return -EINVAL;

		ret = -EINVAL;

		goto release_raw;

	}



	/* Read CRCs */

	ret = sscanf(cfg.raw + cfg.raw_pos, "%x%n", &info_crc, &offset);

	if (ret != 1) {

		dev_err(dev, "Bad format: failed to parse Info CRC\n");

		return -EINVAL;

		ret = -EINVAL;

		goto release_raw;

	}

	cfg.raw_pos += offset;



	ret = sscanf(cfg.raw + cfg.raw_pos, "%x%n", &config_crc, &offset);

	if (ret != 1) {

		dev_err(dev, "Bad format: failed to parse Config CRC\n");

		return -EINVAL;

		ret = -EINVAL;

		goto release_raw;

	}

	cfg.raw_pos += offset;
@@ -1530,8 +1540,10 @@ static int mxt_update_cfg(struct mxt_data *data, const struct firmware *fw) 
			MXT_INFO_CHECKSUM_SIZE;

	cfg.mem_size = data->mem_size - cfg.start_ofs;

	cfg.mem = kzalloc(cfg.mem_size, GFP_KERNEL);

	if (!cfg.mem)

		return -ENOMEM;

	if (!cfg.mem) {

		ret = -ENOMEM;

		goto release_raw;

	}



	ret = mxt_prepare_cfg_mem(data, &cfg);

	if (ret)
@@ -1570,6 +1582,8 @@ static int mxt_update_cfg(struct mxt_data *data, const struct firmware *fw) 
	/* T7 config may have changed */

	mxt_init_t7_power_cfg(data);



release_raw:

	kfree(cfg.raw);

release_mem:

	kfree(cfg.mem);

	return ret;