[PATCH] drm/ttm: Use scnprintf() for avoiding potential buffer overflow

[Christian König]

Am 11.03.20 um 08:52 schrieb Huang Rui:
> On Wed, Mar 11, 2020 at 03:34:52PM +0800, Takashi Iwai wrote:
>> Since snprintf() returns the would-be-output size instead of the
>> actual output size, the succeeding calls may go beyond the given
>> buffer limit.  Fix it by replacing with scnprintf().
>>
>> Signed-off-by: Takashi Iwai <tiwai at suse.de>
> Reviewed-by: Huang Rui <ray.huang at amd.com>

Reviewed-by: Christian König <christian.koenig at amd.com>

Takashi, should I push this to drm-misc-next or do you want to merge 
that somehow else?

Thanks,
Christian.

>
>> ---
>>   drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
>> index bf876faea592..faefaaef7909 100644
>> --- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
>> +++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
>> @@ -604,7 +604,7 @@ static struct dma_pool *ttm_dma_pool_init(struct device *dev, gfp_t flags,
>>   	p = pool->name;
>>   	for (i = 0; i < ARRAY_SIZE(t); i++) {
>>   		if (type & t[i]) {
>> -			p += snprintf(p, sizeof(pool->name) - (p - pool->name),
>> +			p += scnprintf(p, sizeof(pool->name) - (p - pool->name),
>>   				      "%s", n[i]);
>>   		}
>>   	}
>> -- 
>> 2.16.4
>>