of: fdt: add missing allocation-failure check

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@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index c89d5d231a0e30eb4d1a458523e8ef4723b5e6d3..6a43fd3d057605e499331e3115f4dea0dc0882d0 100644 (file)
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -505,6 +505,9 @@ static void *__unflatten_device_tree(const void *blob,
 
        /* 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);