Commit 482137bf authored May 16, 2018 by Frank Rowand Committed by Rob Herring May 23, 2018

of: overlay: validate offset from property fixups



The smatch static checker marks the data in offset as untrusted,
leading it to warn:

  drivers/of/resolver.c:125 update_usages_of_a_phandle_reference()
  error: buffer underflow 'prop->value' 's32min-s32max'

Add check to verify that offset is within the property data.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>

parent 3b9cf790

drivers/of/resolver.c

+5 −0

Original line number	Original line	Diff line number	Diff line
	@@ -122,6 +122,11 @@ static int update_usages_of_a_phandle_reference(struct device_node *overlay,
	goto err_fail;		goto err_fail;
	}		}

			if (offset < 0 \|\| offset + sizeof(__be32) > prop->length) {
			err = -EINVAL;
			goto err_fail;
			}

	(__be32 )(prop->value + offset) = cpu_to_be32(phandle);		(__be32 )(prop->value + offset) = cpu_to_be32(phandle);
	}		}