aboutsummaryrefslogtreecommitdiff
path: root/mm
diff options
context:
space:
mode:
authorAdam Litke <agl@us.ibm.com>2007-01-30 14:35:39 -0800
committerChris Wright <chrisw@sous-sol.org>2007-02-05 08:31:44 -0800
commit8b0165ce42354878b66482f34149d99660dbcdb0 (patch)
treee68910ea6da160ac7bfa93453d4998129836eefa /mm
parente435bb1a3314e17118fd873290b198813537e864 (diff)
[PATCH] Don't allow the stack to grow into hugetlb reserved regions
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 <agl@us.ibm.com> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/mmap.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index 7b40abd7cba..6b061ecaaa6 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1477,6 +1477,7 @@ static int acct_stack_growth(struct vm_area_struct * vma, unsigned long size, un
{
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_area_struct * vma, unsigned long size, un
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.