[RFC PATCH v6 09/26] mm/mmap: Prevent Shadow Stack VMA merges
From: Yu-cheng Yu <hidden>
Date: 2018-11-19 21:54:25
Also in:
linux-arch, linux-doc, linux-mm, lkml
Subsystem:
memory management, memory mapping, the rest · Maintainers:
Andrew Morton, Liam R. Howlett, Lorenzo Stoakes, Linus Torvalds
To prevent function call/return spills into the next shadow stack area, do not merge shadow stack areas. Signed-off-by: Yu-cheng Yu <redacted> --- mm/mmap.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/mm/mmap.c b/mm/mmap.c
index 6c04292e16a7..30836512ca79 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c@@ -1147,6 +1147,12 @@ 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