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Input: atmel_mxt_ts - zero terminate config firmware file

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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: Nick Dyer <nick.dyer@itdev.co.uk>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Nick Dyer 2018-07-27 11:46:46 -07:00 committed by Dmitry Torokhov
parent f865df7364
commit a4891f1058
1 changed files with 24 additions and 10 deletions
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34
drivers/input/touchscreen/atmel_mxt_ts.c
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@ -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;