From bd6a2c23119e3009f6f950ebbdb45351e946c013 Mon Sep 17 00:00:00 2001
From: Balazs Gerofi <bgerofi@riken.jp>
Date: Thu, 18 Aug 2016 07:32:31 +0900
Subject: [PATCH] sys_mmap(): correct initial address check

---
 arch/x86/kernel/syscall.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/syscall.c b/arch/x86/kernel/syscall.c
index a37b2d64..d6819a18 100644
--- a/arch/x86/kernel/syscall.c
+++ b/arch/x86/kernel/syscall.c
@@ -1434,9 +1434,8 @@ SYSCALL_DECLARE(mmap)
 		goto out;
 	}
 
-	if ((addr < region->user_start)
-			|| (region->user_end <= addr)
-			|| ((region->user_end - addr) < len)) {
+	if ((flags & MAP_FIXED) && ((addr < region->user_start)
+			|| (region->user_end <= addr))) {
 		ekprintf("sys_mmap(%lx,%lx,%x,%x,%x,%lx):ENOMEM\n",
 				addr0, len0, prot, flags0, fd, off0);
 		error = -ENOMEM;