Re: [PATCH] accel/ivpu: prevent uninitialized data bug in debugfs

On 25-May-26 9:25, Wachowski, Karol wrote:
> On 25-May-26 9:14, Dan Carpenter wrote:
>> The simple_write_to_buffer() will only initialize data starting from
>> the *pos offset so if it's non-zero then the first part of the buffer
>> uninitialized.  Really, if *pos is non-zero then this code won't work
>> so just check for that at the start of the function.
>>
>> Fixes: 320323d2e545 ("accel/ivpu: Add debugfs interface for setting 
>> HWS priority bands")
>> Signed-off-by: Dan Carpenter <[email protected]>
>> ---
>>   drivers/accel/ivpu/ivpu_debugfs.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/accel/ivpu/ivpu_debugfs.c b/drivers/accel/ivpu/ 
>> ivpu_debugfs.c
>> index 189dbe94cf14..dc20bc73c6ed 100644
>> --- a/drivers/accel/ivpu/ivpu_debugfs.c
>> +++ b/drivers/accel/ivpu/ivpu_debugfs.c
>> @@ -450,7 +450,7 @@ priority_bands_fops_write(struct file *file, const 
>> char __user *user_buf, size_t
>>       u32 band;
>>       int ret;
>> -    if (size >= sizeof(buf))
>> +    if (*pos != 0 || size >= sizeof(buf))
>>           return -EINVAL;
>>       ret = simple_write_to_buffer(buf, sizeof(buf) - 1, pos, 
>> user_buf, size);
> 
> Thanks for submission.
> 
> Reviewed-by: Karol Wachowski <[email protected]>

Applied to drm-misc-fixes.