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

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: b739dffa5d57 ("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>

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 43cf60479b9e18eb0eec35f39c147deccd8fe8dd..98b1cf78ecac7b337699d866197d2d6477e2767a 100644 (file)
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -355,6 +355,7 @@ int of_irq_parse_one(struct device_node *device, int index, struct of_phandle_ar
                return of_irq_parse_oldworld(device, index, out_irq);
 
        /* Get the reg property (if any) */
+       addr_len = 0;
        addr = of_get_property(device, "reg", &addr_len);
 
        /* Prevent out-of-bounds read in case of longer interrupt parent address size */