selinux: apply execstack check on thread stacks
The execstack check was only being applied on the main
process stack. Thread stacks allocated via mmap were
only subject to the execmem permission check. Augment
the check to apply to the current thread stack as well.
Note that this does NOT prevent making a different thread's
stack executable.
Suggested-by: Nick Kralevich <nnk@google.com>
Acked-by: Nick Kralevich <nnk@google.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index bbff80c..a00ab81 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3479,8 +3479,9 @@
vma->vm_end <= vma->vm_mm->brk) {
rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
} else if (!vma->vm_file &&
- vma->vm_start <= vma->vm_mm->start_stack &&
- vma->vm_end >= vma->vm_mm->start_stack) {
+ ((vma->vm_start <= vma->vm_mm->start_stack &&
+ vma->vm_end >= vma->vm_mm->start_stack) ||
+ vma_is_stack_for_task(vma, current))) {
rc = current_has_perm(current, PROCESS__EXECSTACK);
} else if (vma->vm_file && vma->anon_vma) {
/*
