of/irq: Fix using uninitialized variable @addr_len in API of_irq_parse_one()

commit 0f7ca6f69354e0c3923bbc28c92d0ecab4d50a3e upstream.

of_irq_parse_one() may use uninitialized variable @addr_len as shown below:

// @addr_len is uninitialized
int addr_len;

// This operation does not touch @addr_len if it fails.
addr = of_get_property(device, "reg", &addr_len);

// Use uninitialized @addr_len if the operation fails.
if (addr_len > sizeof(addr_buf))
	addr_len = sizeof(addr_buf);

// Check the operation result here.
if (addr)
	memcpy(addr_buf, addr, addr_len);

Fix by initializing @addr_len before the operation.

Fixes: b739dffa ("of/irq: Prevent device address out-of-bounds read in interrupt map walk")
Cc: stable@vger.kernel.org
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20241209-of_irq_fix-v1-4-782f1419c8a1@quicinc.com


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