diff options
Diffstat (limited to 'tags/2.6.18-5/30033_prevent-stack-growth-into-hugetlb-region.patch')
| -rw-r--r-- | tags/2.6.18-5/30033_prevent-stack-growth-into-hugetlb-region.patch | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/tags/2.6.18-5/30033_prevent-stack-growth-into-hugetlb-region.patch b/tags/2.6.18-5/30033_prevent-stack-growth-into-hugetlb-region.patch new file mode 100644 index 0000000..caa7fa7 --- /dev/null +++ b/tags/2.6.18-5/30033_prevent-stack-growth-into-hugetlb-region.patch @@ -0,0 +1,47 @@ +From: Adam Litke <agl@us.ibm.com> +Date: Tue, 30 Jan 2007 22:35:39 +0000 (-0800) +Subject: [PATCH] Don't allow the stack to grow into hugetlb reserved regions +X-Git-Tag: v2.6.20-rc7~10 +X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=0d59a01bc461bbab4017ff449b8401151ef44cf6 + +[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: Linus Torvalds <torvalds@linux-foundation.org> +--- + +diff --git a/mm/mmap.c b/mm/mmap.c +index 9717337..cc3a208 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. |