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Commit 2a4d2032 authored by Irina Tirdea's avatar Irina Tirdea Committed by Jonathan Cameron
Browse files

iio: accel: mma9551_core: prevent buffer overrun 



The mma9551 functions that read/write word arrays from the
device have a limit for the buffer size given by the device
specifications.

Check that the requested buffer length is within required limits
when transferring word arrays. This will prevent buffer overrun
in the mma9551_read/write_*_words functions and also in the
mma9551_transfer call when writing into the MBOX response/request
structure.

Signed-off-by: default avatarIrina Tirdea <irina.tirdea@intel.com>
Reported-by: default avatarHartmut Knaack <knaack.h@gmx.de>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent cd62322a

drivers/iio/accel/mma9551_core.c

+18 −3
Original line number Diff line number Diff line
@@ -389,7 +389,12 @@ int mma9551_read_config_words(struct i2c_client *client, u8 app_id, 
{

	int ret, i;

	int len_words = len / sizeof(u16);

	__be16 be_buf[MMA9551_MAX_MAILBOX_DATA_REGS];

	__be16 be_buf[MMA9551_MAX_MAILBOX_DATA_REGS / 2];



	if (len_words > ARRAY_SIZE(be_buf)) {

		dev_err(&client->dev, "Invalid buffer size %d\n", len);

		return -EINVAL;

	}



	ret = mma9551_transfer(client, app_id, MMA9551_CMD_READ_CONFIG,

			       reg, NULL, 0, (u8 *) be_buf, len);
@@ -424,7 +429,12 @@ int mma9551_read_status_words(struct i2c_client *client, u8 app_id, 
{

	int ret, i;

	int len_words = len / sizeof(u16);

	__be16 be_buf[MMA9551_MAX_MAILBOX_DATA_REGS];

	__be16 be_buf[MMA9551_MAX_MAILBOX_DATA_REGS / 2];



	if (len_words > ARRAY_SIZE(be_buf)) {

		dev_err(&client->dev, "Invalid buffer size %d\n", len);

		return -EINVAL;

	}



	ret = mma9551_transfer(client, app_id, MMA9551_CMD_READ_STATUS,

			       reg, NULL, 0, (u8 *) be_buf, len);
@@ -459,7 +469,12 @@ int mma9551_write_config_words(struct i2c_client *client, u8 app_id, 
{

	int i;

	int len_words = len / sizeof(u16);

	__be16 be_buf[MMA9551_MAX_MAILBOX_DATA_REGS];

	__be16 be_buf[(MMA9551_MAX_MAILBOX_DATA_REGS - 1) / 2];



	if (len_words > ARRAY_SIZE(be_buf)) {

		dev_err(&client->dev, "Invalid buffer size %d\n", len);

		return -EINVAL;

	}



	for (i = 0; i < len_words; i++)

		be_buf[i] = cpu_to_be16(buf[i]);