4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold <johan@xxxxxxxxxx> commit 49e67dd17649b60b4d54966e18ec9c80198227f0 upstream. 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") Signed-off-by: Johan Hovold <johan@xxxxxxxxxx> Signed-off-by: Rob Herring <robh@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/of/fdt.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -505,6 +505,9 @@ static void *__unflatten_device_tree(con /* 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);