From 2d3fed3a43390ded98cf75be48b8c16cf65af1b6 Mon Sep 17 00:00:00 2001
From: Kalesh Singh <kaleshsingh@google.com>
Date: Fri, 17 Nov 2023 09:42:19 -0800
Subject: [PATCH] ANDROID: 16K: mprotect: __PAGE_ALIGN addr and len

In page-compat mode, mprotect() syscalls must be at __PAGE_ALIGN-ed
addresses and of __PAGE_SIZE-multiple length.

Bug: 383389337
Bug: 315325080
Bug: 302403436
Change-Id: I5ece654ea921cad692af0d3aa7dba422f54d08b8
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
---
 mm/mprotect.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/mprotect.c b/mm/mprotect.c
index 516b1d847e2c..0d37a7308cd9 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -17,6 +17,7 @@
 #include <linux/highmem.h>
 #include <linux/security.h>
 #include <linux/mempolicy.h>
+#include <linux/page_size_compat.h>
 #include <linux/personality.h>
 #include <linux/syscalls.h>
 #include <linux/swap.h>
@@ -726,11 +727,11 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
 	if (grows == (PROT_GROWSDOWN|PROT_GROWSUP)) /* can't be both */
 		return -EINVAL;
 
-	if (start & ~PAGE_MASK)
+	if (!__PAGE_ALIGNED(start))
 		return -EINVAL;
 	if (!len)
 		return 0;
-	len = PAGE_ALIGN(len);
+	len = __PAGE_ALIGN(len);
 	end = start + len;
 	if (end <= start)
 		return -ENOMEM;