From: Liam Howlett <liam.howlett@xxxxxxxxxx> Subject: mm/mremap: use vma_lookup() in vma_to_resize() Use vma_lookup() to find the VMA at a specific address. As vma_lookup() will return NULL if the address is not within any VMA, the start address no longer needs to be validated. Link: https://lkml.kernel.org/r/20210521174745.2219620-21-Liam.Howlett@xxxxxxxxxx Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx> Reviewed-by: Laurent Dufour <ldufour@xxxxxxxxxxxxx> Acked-by: David Hildenbrand <david@xxxxxxxxxx> Acked-by: Davidlohr Bueso <dbueso@xxxxxxx> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/mremap.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/mm/mremap.c~mm-mremap-use-vma_lookup-in-vma_to_resize +++ a/mm/mremap.c @@ -634,10 +634,11 @@ static struct vm_area_struct *vma_to_res unsigned long *p) { struct mm_struct *mm = current->mm; - struct vm_area_struct *vma = find_vma(mm, addr); + struct vm_area_struct *vma; unsigned long pgoff; - if (!vma || vma->vm_start > addr) + vma = vma_lookup(mm, addr); + if (!vma) return ERR_PTR(-EFAULT); /* _