lkml.org 
[lkml]   [2018]   [Jul]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v1 07/10] Input: atmel_mxt_ts - zero terminate config firmware file
Date
From: Nick Dyer <nick.dyer@itdev.co.uk>

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>
---
drivers/input/touchscreen/atmel_mxt_ts.c | 36 +++++++++++++++++-------
1 file changed, 26 insertions(+), 10 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 0ce126e918f1..2d1fddafb7f9 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -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 +1451,21 @@ 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 = kzalloc(fw->size + 1, GFP_KERNEL);
+ if (!cfg.raw)
+ return -ENOMEM;
+
+ memcpy(cfg.raw, fw->data, fw->size);
+ cfg.raw[fw->size] = '\0';
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 +1477,8 @@ 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 +1486,30 @@ 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 +1542,10 @@ 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 +1584,8 @@ 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;
--
2.17.1
\
 
 \ /
  Last update: 2018-07-20 23:53    [W:0.141 / U:0.452 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site