From: Laura Abbott <labbott@redhat.com>
Date: Tue, 4 Apr 2017 21:09:00 +0000 (-0700)
Subject: mm/usercopy: Drop extra is_vmalloc_or_module() check
X-Git-Tag: android-x86-8.1-r1~3664^2
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=517e1fbeb6;p=android-x86%2Fkernel.git

mm/usercopy: Drop extra is_vmalloc_or_module() check

Previously virt_addr_valid() was insufficient to validate if virt_to_page()
could be called on an address on arm64. This has since been fixed up so
there is no need for the extra check. Drop it.

Signed-off-by: Laura Abbott <labbott@redhat.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---

diff --git a/mm/usercopy.c b/mm/usercopy.c
index 1eba99baf1cf..a9852b24715d 100644
--- a/mm/usercopy.c
+++ b/mm/usercopy.c
@@ -200,17 +200,6 @@ static inline const char *check_heap_object(const void *ptr, unsigned long n,
 {
 	struct page *page;
 
-	/*
-	 * Some architectures (arm64) return true for virt_addr_valid() on
-	 * vmalloced addresses. Work around this by checking for vmalloc
-	 * first.
-	 *
-	 * We also need to check for module addresses explicitly since we
-	 * may copy static data from modules to userspace
-	 */
-	if (is_vmalloc_or_module_addr(ptr))
-		return NULL;
-
 	if (!virt_addr_valid(ptr))
 		return NULL;