Re: [PATCH] mm/cma: fix reserved page leak on activation failure

[Usama Arif <usama.arif@linux.dev>]

On 26/05/2026 13:44, Muchun Song wrote:
> 
> 
>> On May 26, 2026, at 19:51, Oscar Salvador (SUSE) <osalvador@kernel.org> wrote:
>>
>> On Tue, May 26, 2026 at 04:30:03AM -0700, Usama Arif wrote:
>>> On Fri, 22 May 2026 14:26:58 +0800 Muchun Song <songmuchun@bytedance.com> wrote:
>> ...
>>>> diff --git a/mm/cma.c b/mm/cma.c
>>>> index c7ca567f4c5c..a30075507d41 100644
>>>> --- a/mm/cma.c
>>>> +++ b/mm/cma.c
>>>> @@ -188,10 +188,13 @@ static void __init cma_activate_area(struct cma *cma)
>>>>
>>>>    /* Expose all pages to the buddy, they are useless for CMA. */
>>>>    if (!test_bit(CMA_RESERVE_PAGES_ON_ERROR, &cma->flags)) {
>>>> -        for (r = 0; r < allocrange; r++) {
>>>> +        for (r = 0; r < cma->nranges; r++) {
>>>> +            unsigned long start_pfn;
>>>> +
>>>>            cmr = &cma->ranges[r];
>>>> +            start_pfn = r < allocrange ? early_pfn[r] : cmr->early_pfn;
>>>
>>> Should this be r <= allocrange?
> 
> Yes. So I sent a v2 to fix it last Saturday.
> 
> https://lore.kernel.org/linux-mm/20260523060123.2207992-1-songmuchun@bytedance.com/
> 
> Thanks.

Ah still catching up on the mailing list. Thanks!

> 
>>
>> Yes, I think you are right. I missed that.
>>
>> early_pfn[alloc_range] holds the last assignment, so we should start
>> from the next one reading cmr->early_pfn.
>>
>>
>>
>> --
>> Oscar Salvador
>> SUSE Labs