Re: [PATCH] mm/mmap: Fix vma_merge() offset when expanding the next vma

[David Hildenbrand <david@redhat.com>]

On 30.01.23 20:57, Liam R. Howlett wrote:
> The vm_pgoff was being set incorrectly when expanding the next VMA to a
> lower address.  Fix the issue by using the mid->vm_pgoff value for this
> merge case (aka case 8).  Note that this does not change case 3's
> vm_pgoff as next and mid are the same VMA.
> 
> Reported-by: Sanan Hasanov <sanan.hasanov@knights.ucf.edu>
> Link: https://lore.kernel.org/linux-mm/IA1PR07MB983017D2FBA174D2FF78CEB6ABCE9@IA1PR07MB9830.namprd07.prod.outlook.com/
> Cc: Matthew Wilcox <willy@infradead.org>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Hugh Dickins <hughd@google.com>

Fixes: ?

> Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
> ---
>   mm/mmap.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/mmap.c b/mm/mmap.c
> index 00d90bbc250e..614ea2d93b0a 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -978,7 +978,7 @@ struct vm_area_struct *vma_merge(struct vma_iterator *vmi, struct mm_struct *mm,
>   			vma = next;			/* case 3 */
>   			vma_start = addr;
>   			vma_end = next->vm_end;
> -			vma_pgoff = next->vm_pgoff;
> +			vma_pgoff = mid->vm_pgoff;
>   			err = 0;
>   			if (mid != next) {		/* case 8 */
>   				remove = mid;

Acked-by: David Hildenbrand <david@redhat.com>

Thanks!

-- 
Thanks,

David / dhildenb