[SECURITY PATCH 23/28] emu: Make grub_free(NULL) safe

[Daniel Kiper]

From: Peter Jones <pjones@redhat.com>

The grub_free() implementation in grub-core/kern/mm.c safely handles
NULL pointers, and code at many places depends on this. We don't know
that the same is true on all host OSes, so we need to handle the same
behavior in grub-emu's implementation.

Signed-off-by: Peter Jones <pjones@redhat.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---
 grub-core/kern/emu/mm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/grub-core/kern/emu/mm.c b/grub-core/kern/emu/mm.c
index 145b01d37..4d1046a21 100644
--- a/grub-core/kern/emu/mm.c
+++ b/grub-core/kern/emu/mm.c
@@ -60,7 +60,8 @@ grub_zalloc (grub_size_t size)
 void
 grub_free (void *ptr)
 {
-  free (ptr);
+  if (ptr)
+    free (ptr);
 }
 
 void *
-- 
2.11.0