Re: [PATCH] mm/huge_memory: Fix to make vma_adjust_trans_huge() use find_vma() correctly

On 21.11.24 13:41, Jeongjun Park wrote:

vma_adjust_trans_huge() uses find_vma() to get the VMA, but find_vma() uses the returned pointer without any verification, even though it may return NULL. In this case, NULL pointer dereference may occur, so to prevent this, vma_adjust_trans_huge() should be fix to verify the return value of find_vma().

Cc: stable@vger.kernel.org Fixes: 685405020b9f ("mm/khugepaged: stop using vma linked list")

If that's an issue, wouldn't it have predated that commit?

struct vm_area_struct *next = vma->vm_next; unsigned long nstart = next->vm_start;

Would have also assumed that there is a next VMA that can be dereferenced, no?