[PATCH io_uring-6.18 1/1] io_uring: fix types for region size calulation

[PATCH io_uring-6.18 1/1] io_uring: fix types for region size calulation

[Pavel Begunkov]

->nr_pages is int, it needs type extension before calculating the region
size.

Fixes: a90558b36ccee ("io_uring/memmap: helper for pinning region pages")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 io_uring/memmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io_uring/memmap.c b/io_uring/memmap.c
index 2e99dffddfc5..fab79c7b3157 100644
--- a/io_uring/memmap.c
+++ b/io_uring/memmap.c
@@ -135,7 +135,7 @@ static int io_region_pin_pages(struct io_ring_ctx *ctx,
 				struct io_mapped_region *mr,
 				struct io_uring_region_desc *reg)
 {
-	unsigned long size = mr->nr_pages << PAGE_SHIFT;
+	unsigned long size = (size_t)mr->nr_pages << PAGE_SHIFT;
 	struct page **pages;
 	int nr_pages;
 
-- 
2.49.0

Re: [PATCH io_uring-6.18 1/1] io_uring: fix types for region size calulation

[Jens Axboe]

On 11/5/25 8:47 AM, Pavel Begunkov wrote:
> ->nr_pages is int, it needs type extension before calculating the region
> size.
> 
> Fixes: a90558b36ccee ("io_uring/memmap: helper for pinning region pages")
> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
> ---
>  io_uring/memmap.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/io_uring/memmap.c b/io_uring/memmap.c
> index 2e99dffddfc5..fab79c7b3157 100644
> --- a/io_uring/memmap.c
> +++ b/io_uring/memmap.c
> @@ -135,7 +135,7 @@ static int io_region_pin_pages(struct io_ring_ctx *ctx,
>  				struct io_mapped_region *mr,
>  				struct io_uring_region_desc *reg)
>  {
> -	unsigned long size = mr->nr_pages << PAGE_SHIFT;
> +	unsigned long size = (size_t)mr->nr_pages << PAGE_SHIFT;
>  	struct page **pages;
>  	int nr_pages;

Should probably consistently use a size_t, everywhere else does. Doesn't
matter here as io_pin_pages() does the right thing anyway.

-- 
Jens Axboe

Re: [PATCH io_uring-6.18 1/1] io_uring: fix types for region size calulation

[Pavel Begunkov]

On 11/5/25 18:44, Jens Axboe wrote:
> On 11/5/25 8:47 AM, Pavel Begunkov wrote:
>> ->nr_pages is int, it needs type extension before calculating the region
>> size.
>>
>> Fixes: a90558b36ccee ("io_uring/memmap: helper for pinning region pages")
>> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
>> ---
>>   io_uring/memmap.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/io_uring/memmap.c b/io_uring/memmap.c
>> index 2e99dffddfc5..fab79c7b3157 100644
>> --- a/io_uring/memmap.c
>> +++ b/io_uring/memmap.c
>> @@ -135,7 +135,7 @@ static int io_region_pin_pages(struct io_ring_ctx *ctx,
>>   				struct io_mapped_region *mr,
>>   				struct io_uring_region_desc *reg)
>>   {
>> -	unsigned long size = mr->nr_pages << PAGE_SHIFT;
>> +	unsigned long size = (size_t)mr->nr_pages << PAGE_SHIFT;
>>   	struct page **pages;
>>   	int nr_pages;
> 
> Should probably consistently use a size_t, everywhere else does. Doesn't
> matter here as io_pin_pages() does the right thing anyway.

I have a patch on the topic as I needed it myself, but didn't
include it into the fix.

-- 
Pavel Begunkov

Re: [PATCH io_uring-6.18 1/1] io_uring: fix types for region size calulation

[Jens Axboe]

On 11/6/25 5:09 AM, Pavel Begunkov wrote:
> On 11/5/25 18:44, Jens Axboe wrote:
>> On 11/5/25 8:47 AM, Pavel Begunkov wrote:
>>> ->nr_pages is int, it needs type extension before calculating the region
>>> size.
>>>
>>> Fixes: a90558b36ccee ("io_uring/memmap: helper for pinning region pages")
>>> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
>>> ---
>>>   io_uring/memmap.c | 2 +-
>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/io_uring/memmap.c b/io_uring/memmap.c
>>> index 2e99dffddfc5..fab79c7b3157 100644
>>> --- a/io_uring/memmap.c
>>> +++ b/io_uring/memmap.c
>>> @@ -135,7 +135,7 @@ static int io_region_pin_pages(struct io_ring_ctx *ctx,
>>>                   struct io_mapped_region *mr,
>>>                   struct io_uring_region_desc *reg)
>>>   {
>>> -    unsigned long size = mr->nr_pages << PAGE_SHIFT;
>>> +    unsigned long size = (size_t)mr->nr_pages << PAGE_SHIFT;
>>>       struct page **pages;
>>>       int nr_pages;
>>
>> Should probably consistently use a size_t, everywhere else does. Doesn't
>> matter here as io_pin_pages() does the right thing anyway.
> 
> I have a patch on the topic as I needed it myself, but didn't
> include it into the fix.

That's fine, better that way too imho.

-- 
Jens Axboe

Re: [PATCH io_uring-6.18 1/1] io_uring: fix types for region size calulation

[Jens Axboe]

On Wed, 05 Nov 2025 15:47:01 +0000, Pavel Begunkov wrote:
> ->nr_pages is int, it needs type extension before calculating the region
> size.
> 
> 

Applied, thanks!

[1/1] io_uring: fix types for region size calulation
      commit: 1fd5367391bf0eeb09e624c4ab45121b54eaab96

Best regards,
-- 
Jens Axboe