[patch] iio: accel: sca3000: memory corruption in sca3000_read_first_n_hw_rb()

[patch] iio: accel: sca3000: memory corruption in sca3000_read_first_n_hw_rb()

[Dan Carpenter]

"num_read" is in byte units but we are write u16s so we end up write
twice as much as intended.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/drivers/staging/iio/accel/sca3000_ring.c b/drivers/staging/iio/accel/sca3000_ring.c
index 23685e7..bd2c69f 100644
--- a/drivers/staging/iio/accel/sca3000_ring.c
+++ b/drivers/staging/iio/accel/sca3000_ring.c
@@ -116,7 +116,7 @@ static int sca3000_read_first_n_hw_rb(struct iio_buffer *r,
 	if (ret)
 		goto error_ret;
 
-	for (i = 0; i < num_read; i++)
+	for (i = 0; i < num_read / sizeof(u16); i++)
 		*(((u16 *)rx) + i) = be16_to_cpup((__be16 *)rx + i);
 
 	if (copy_to_user(buf, rx, num_read))

Re: [patch] iio: accel: sca3000: memory corruption in sca3000_read_first_n_hw_rb()

[Jonathan Cameron]

On 08/08/15 20:16, Dan Carpenter wrote:
> "num_read" is in byte units but we are write u16s so we end up write
> twice as much as intended.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Hi Dan,

This is fine. Given it's an old bug, Greg is not going to take this
sort of fix until after the merge window.   I won't be doing another
pull to him to go in during the merge window.  Hence fastest route
will be as a fix post 4.3-rc1.

Give me a poke if I haven't picked it up and sent it on by rc2 or so.

Thanks and good find.

Jonathan
> 
> diff --git a/drivers/staging/iio/accel/sca3000_ring.c b/drivers/staging/iio/accel/sca3000_ring.c
> index 23685e7..bd2c69f 100644
> --- a/drivers/staging/iio/accel/sca3000_ring.c
> +++ b/drivers/staging/iio/accel/sca3000_ring.c
> @@ -116,7 +116,7 @@ static int sca3000_read_first_n_hw_rb(struct iio_buffer *r,
>  	if (ret)
>  		goto error_ret;
>  
> -	for (i = 0; i < num_read; i++)
> +	for (i = 0; i < num_read / sizeof(u16); i++)
>  		*(((u16 *)rx) + i) = be16_to_cpup((__be16 *)rx + i);
>  
>  	if (copy_to_user(buf, rx, num_read))
> --
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Re: [patch] iio: accel: sca3000: memory corruption in sca3000_read_first_n_hw_rb()

[Jonathan Cameron]

On 15/08/15 21:05, Jonathan Cameron wrote:
> On 08/08/15 20:16, Dan Carpenter wrote:
>> "num_read" is in byte units but we are write u16s so we end up write
>> twice as much as intended.
>>
>> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> Hi Dan,
> 
> This is fine. Given it's an old bug, Greg is not going to take this
> sort of fix until after the merge window.   I won't be doing another
> pull to him to go in during the merge window.  Hence fastest route
> will be as a fix post 4.3-rc1.
> 
> Give me a poke if I haven't picked it up and sent it on by rc2 or so.
> 
> Thanks and good find.
> 
> Jonathan
Nearly forgot this one!

Anyhow, applied to the fixes-togreg branch of iio.git and marked for stable.

Jonathan
>>
>> diff --git a/drivers/staging/iio/accel/sca3000_ring.c b/drivers/staging/iio/accel/sca3000_ring.c
>> index 23685e7..bd2c69f 100644
>> --- a/drivers/staging/iio/accel/sca3000_ring.c
>> +++ b/drivers/staging/iio/accel/sca3000_ring.c
>> @@ -116,7 +116,7 @@ static int sca3000_read_first_n_hw_rb(struct iio_buffer *r,
>>  	if (ret)
>>  		goto error_ret;
>>  
>> -	for (i = 0; i < num_read; i++)
>> +	for (i = 0; i < num_read / sizeof(u16); i++)
>>  		*(((u16 *)rx) + i) = be16_to_cpup((__be16 *)rx + i);
>>  
>>  	if (copy_to_user(buf, rx, num_read))
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-iio" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
> 
> --
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