efi_loader: check length in CreateDeviceNode()

When creating a device path node ensure that the size of the allocated
memory at lest matches the size of the node header.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c
index 6104c7d33b70c2427af0e90e785e802942256b37..10f890f44f660153be523726dfc02b18a489a3bd 100644 (file)
--- a/lib/efi_loader/efi_device_path.c
+++ b/lib/efi_loader/efi_device_path.c
@@ -335,6 +335,9 @@ struct efi_device_path *efi_dp_create_device_node(const u8 type,
 {
        struct efi_device_path *ret;
 
+       if (length < sizeof(struct efi_device_path))
+               return NULL;
+
        ret = dp_alloc(length);
        if (!ret)
                return ret;