releases/4.9.30/of-fdt-add-missing-allocation-failure-check.patch

   1 From 49e67dd17649b60b4d54966e18ec9c80198227f0 Mon Sep 17 00:00:00 2001
   2 From: Johan Hovold <johan@kernel.org>
   3 Date: Wed, 17 May 2017 17:29:09 +0200
   4 Subject: of: fdt: add missing allocation-failure check
   5
   6 From: Johan Hovold <johan@kernel.org>
   7
   8 commit 49e67dd17649b60b4d54966e18ec9c80198227f0 upstream.
   9
  10 The memory allocator passed to __unflatten_device_tree() (e.g. a wrapped
  11 kzalloc) can fail so add the missing sanity check to avoid dereferencing
  12 a NULL pointer.
  13
  14 Fixes: fe14042358fa ("of/flattree: Refactor unflatten_device_tree and add fdt_unflatten_tree")
  15 Signed-off-by: Johan Hovold <johan@kernel.org>
  16 Signed-off-by: Rob Herring <robh@kernel.org>
  17 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  18
  19 ---
  20  drivers/of/fdt.c |    3 +++
  21  1 file changed, 3 insertions(+)
  22
  23 --- a/drivers/of/fdt.c
  24 +++ b/drivers/of/fdt.c
  25 @@ -505,6 +505,9 @@ static void *__unflatten_device_tree(con
  26
  27         /* Allocate memory for the expanded device tree */
  28         mem = dt_alloc(size + 4, __alignof__(struct device_node));
  29 +       if (!mem)
  30 +               return NULL;
  31 +
  32         memset(mem, 0, size);
  33
  34         *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);