Re: [PATCH] fix error reporting in move_pages syscall

[KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>]

> vma returned by find_vma does not necessary include given address. If
> this happens code tries to follow page outside of any vma and returns
> ENOENT instead of EFAULT.
> 
> Signed-off-by: Gleb Natapov <gleb@redhat.com>
> diff --git a/mm/migrate.c b/mm/migrate.c
> index 38e7cad..b91a253 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -841,7 +841,7 @@ static int do_move_page_to_node_array(struct mm_struct *mm,
>  
>  		err = -EFAULT;
>  		vma = find_vma(mm, pp->addr);
> -		if (!vma || !vma_migratable(vma))
> +		if (!vma || pp->addr < vma->vm_start || !vma_migratable(vma))
>  			goto set_status;
>  
>  		page = follow_page(vma, pp->addr, FOLL_GET);
> @@ -1005,7 +1005,7 @@ static void do_pages_stat_array(struct mm_struct *mm, unsigned long nr_pages,
>  		int err = -EFAULT;
>  
>  		vma = find_vma(mm, addr);
> -		if (!vma)
> +		if (!vma || addr < vma->vm_start)
>  			goto set_status;
>  
>  		page = follow_page(vma, addr, 0);
> --
> 			Gleb.

Looks good to me.
	Revewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>




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