[RFC PATCH v2 15/27] mm/mprotect: Prevent mprotect from changing shadow stack
From: Yu-cheng Yu <hidden>
Date: 2018-07-10 22:33:07
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
Signed-off-by: Yu-cheng Yu <redacted> --- mm/mprotect.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 625608bc8962..128dcb880c12 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c@@ -446,6 +446,15 @@ static int do_mprotect_pkey(unsigned long start, size_t len, error = -ENOMEM; if (!vma) goto out; + + /* + * Do not allow changing shadow stack memory. + */ + if (vma->vm_flags & VM_SHSTK) { + error = -EINVAL; + goto out; + } + prev = vma->vm_prev; if (unlikely(grows & PROT_GROWSDOWN)) { if (vma->vm_start >= end)
--
2.17.1