svn commit: r313442 - head/sys/boot/efi/libefi

[Toomas Soome]

Author: tsoome
Date: Wed Feb  8 15:52:09 2017
New Revision: 313442
URL: https://svnweb.freebsd.org/changeset/base/313442

Log:
  loader: possible NULL pointer dereference in efipart.c
  
  Fix bugs found by Coverity in efipart.c.
  
  The Issue is that efi_devpath_last_node() can return NULL pointer, and
  therefore we should check for it. In real life we really do not
  expect to see it to happen, so we will just error out from the test.
  
  CID:		1371004
  Reported by:	Coverity
  Reviewed by:	allanjude
  Approved by:	allanjude (mentor)
  Differential Revision:	https://reviews.freebsd.org/D9490

Modified:
  head/sys/boot/efi/libefi/efipart.c

Modified: head/sys/boot/efi/libefi/efipart.c
==============================================================================
--- head/sys/boot/efi/libefi/efipart.c	Wed Feb  8 13:37:57 2017	(r313441)
+++ head/sys/boot/efi/libefi/efipart.c	Wed Feb  8 15:52:09 2017	(r313442)
@@ -364,6 +364,9 @@ efipart_hdinfo_add(EFI_HANDLE disk_handl
 	if (disk_devpath == NULL || part_devpath == NULL) {
 		return (ENOENT);
 	}
+	node = (HARDDRIVE_DEVICE_PATH *)efi_devpath_last_node(part_devpath);
+	if (node == NULL)
+		return (ENOENT);	/* This should not happen. */
 
 	pd = malloc(sizeof(pdinfo_t));
 	if (pd == NULL) {
@@ -372,7 +375,6 @@ efipart_hdinfo_add(EFI_HANDLE disk_handl
 	}
 	memset(pd, 0, sizeof(pdinfo_t));
 	STAILQ_INIT(&pd->pd_part);
-	node = (HARDDRIVE_DEVICE_PATH *)efi_devpath_last_node(part_devpath);
 
 	STAILQ_FOREACH(hd, &hdinfo, pd_link) {
 		if (efi_devpath_match(hd->pd_devpath, disk_devpath) != 0) {