To prevent function call/return spills into the next shadow stack area, do not merge shadow stack areas. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx> --- mm/mmap.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/mm/mmap.c b/mm/mmap.c index 7e8c3e8ae75f..b1a921c0de63 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1149,6 +1149,12 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm, if (vm_flags & VM_SPECIAL) return NULL; + /* + * Do not merge shadow stack areas. + */ + if (vm_flags & VM_SHSTK) + return NULL; + if (prev) next = prev->vm_next; else -- 2.17.1
