svn commit: r303753 - head/sys/amd64/amd64

[John Baldwin]

Author: jhb
Date: Thu Aug  4 17:55:23 2016
New Revision: 303753
URL: https://svnweb.freebsd.org/changeset/base/303753

Log:
  Don't permit mappings of invalid physical addresses on amd64 via /dev/mem.
  
  Discussed with:	kib

Modified:
  head/sys/amd64/amd64/mem.c

Modified: head/sys/amd64/amd64/mem.c
==============================================================================
--- head/sys/amd64/amd64/mem.c	Thu Aug  4 17:46:07 2016	(r303752)
+++ head/sys/amd64/amd64/mem.c	Thu Aug  4 17:55:23 2016	(r303753)
@@ -168,9 +168,11 @@ int
 memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
     int prot __unused, vm_memattr_t *memattr __unused)
 {
-	if (dev2unit(dev) == CDEV_MINOR_MEM)
+	if (dev2unit(dev) == CDEV_MINOR_MEM) {
+		if (offset >= (1ULL << cpu_maxphyaddr))
+			return (-1);
 		*paddr = offset;
-	else if (dev2unit(dev) == CDEV_MINOR_KMEM)
+	} else if (dev2unit(dev) == CDEV_MINOR_KMEM)
         	*paddr = vtophys(offset);
 	/* else panic! */
 	return (0);