On Mon, May 22, 2017 at 2:17 PM, <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> The patch below does not apply to the 4.4-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@xxxxxxxxxxxxxxx>.
>
> thanks,
>
> greg k-h
>
> ------------------ original commit in Linus's tree ------------------
>
> From 49e67dd17649b60b4d54966e18ec9c80198227f0 Mon Sep 17 00:00:00 2001
> From: Johan Hovold <johan@xxxxxxxxxx>
> Date: Wed, 17 May 2017 17:29:09 +0200
> Subject: [PATCH] of: fdt: add missing allocation-failure check
>
> The memory allocator passed to __unflatten_device_tree() (e.g. a wrapped
> kzalloc) can fail so add the missing sanity check to avoid dereferencing
> a NULL pointer.
>
> Fixes: fe14042358fa ("of/flattree: Refactor unflatten_device_tree and add fdt_unflatten_tree")
> Cc: stable <stable@xxxxxxxxxxxxxxx> # 2.6.38
> Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
> Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
>
> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
> index a0972219ccfc..0373ae49d24d 100644
> --- a/drivers/of/fdt.c
> +++ b/drivers/of/fdt.c
> @@ -507,6 +507,9 @@ void *__unflatten_device_tree(const void *blob,
The context looks the same, it's just the line number is 416 in v4.4.
>
> /* Allocate memory for the expanded device tree */
> mem = dt_alloc(size + 4, __alignof__(struct device_node));
> + if (!mem)
> + return NULL;
> +
> memset(mem, 0, size);
>
> *(__be32 *)(mem + size) = cpu_to_be32(0xdeadbeef);
>