From: Adam Litke When expanding the stack, we don't currently check if the VMA will cross into an area of the address space that is reserved for hugetlb pages. Subsequent faults on the expanded portion of such a VMA will confuse the low-level MMU code, resulting in an OOPS. Check for this. Signed-off-by: Adam Litke Cc: David Gibson Cc: William Lee Irwin III Cc: Hugh Dickins Signed-off-by: Andrew Morton --- mm/mmap.c | 7 +++++++ 1 files changed, 7 insertions(+) diff -puN mm/mmap.c~dont-allow-the-stack-to-grow-into-hugetlb-reserved-regions mm/mmap.c --- a/mm/mmap.c~dont-allow-the-stack-to-grow-into-hugetlb-reserved-regions +++ a/mm/mmap.c @@ -1477,6 +1477,7 @@ static int acct_stack_growth(struct vm_a { struct mm_struct *mm = vma->vm_mm; struct rlimit *rlim = current->signal->rlim; + unsigned long new_start; /* address space limit tests */ if (!may_expand_vm(mm, grow)) @@ -1496,6 +1497,12 @@ static int acct_stack_growth(struct vm_a return -ENOMEM; } + /* Check to ensure the stack will not grow into a hugetlb-only region */ + new_start = (vma->vm_flags & VM_GROWSUP) ? vma->vm_start : + vma->vm_end - size; + if (is_hugepage_only_range(vma->vm_mm, new_start, size)) + return -EFAULT; + /* * Overcommit.. This must be the final test, as it will * update security statistics. _