[src/trunk]: src/sys/compat/linux/arch/amd64 Make sure %rip is in userland. T...

[maxv <maxv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/17157f4c8069
branches:  trunk
changeset: 351446:17157f4c8069
user:      maxv <maxv%NetBSD.org@localhost>
date:      Mon Feb 13 15:03:18 2017 +0000

description:
Make sure %rip is in userland. This is harmless, since the return to
userland is made with iret instead of sysret in this path. While here, use
size_t.

diffstat:

 sys/compat/linux/arch/amd64/linux_machdep.c |  8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)

diffs (36 lines):

diff -r 22bd00715023 -r 17157f4c8069 sys/compat/linux/arch/amd64/linux_machdep.c
--- a/sys/compat/linux/arch/amd64/linux_machdep.c       Mon Feb 13 14:54:11 2017 +0000
+++ b/sys/compat/linux/arch/amd64/linux_machdep.c       Mon Feb 13 15:03:18 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: linux_machdep.c,v 1.50 2017/02/13 14:54:11 maxv Exp $ */
+/*     $NetBSD: linux_machdep.c,v 1.51 2017/02/13 15:03:18 maxv Exp $ */
 
 /*-
  * Copyright (c) 2005 Emmanuel Dreyfus, all rights reserved.
@@ -33,7 +33,7 @@
 
 #include <sys/cdefs.h>
 
-__KERNEL_RCSID(0, "$NetBSD: linux_machdep.c,v 1.50 2017/02/13 14:54:11 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: linux_machdep.c,v 1.51 2017/02/13 15:03:18 maxv Exp $");
 
 #include <sys/param.h>
 #include <sys/types.h>
@@ -457,7 +457,7 @@
 {
        struct trapframe *tf = arg;
        uint64_t retaddr;
-       int vsyscallnr;
+       size_t vsyscallnr;
 
        /*
         * Check for a vsyscall. %rip must be the fault address,
@@ -487,6 +487,8 @@
         */
        if (copyin((void *)tf->tf_rsp, &retaddr, sizeof retaddr) != 0)
                return 0;
+       if ((vaddr_t)retaddr >= VM_MAXUSER_ADDRESS)
+               return 0;
        tf->tf_rip = retaddr;
        tf->tf_rax = linux_vsyscall_to_syscall[vsyscallnr];
        tf->tf_rsp += 8;        /* "pop" the return address */