[PATCH] of/irq: Refer to actual buffer size in of_irq_parse_one()

[PATCH] of/irq: Refer to actual buffer size in of_irq_parse_one()

[Geert Uytterhoeven]

Replace two open-coded calculations of the buffer size by invocations of
sizeof() on the buffer itself, to make sure the code will always use the
actual buffer size.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
If you think this warrants a Fixes-tag:

    Fixes: b739dffa5d570b41 ("of/irq: Prevent device address out-of-bounds read in interrupt map walk")
---
 drivers/of/irq.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index cc30b471e446045a..36351ad6115eb10e 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -357,8 +357,8 @@ int of_irq_parse_one(struct device_node *device, int index, struct of_phandle_ar
 	addr = of_get_property(device, "reg", &addr_len);
 
 	/* Prevent out-of-bounds read in case of longer interrupt parent address size */
-	if (addr_len > (3 * sizeof(__be32)))
-		addr_len = 3 * sizeof(__be32);
+	if (addr_len > sizeof(addr_buf))
+		addr_len = sizeof(addr_buf);
 	if (addr)
 		memcpy(addr_buf, addr, addr_len);
 
-- 
2.34.1

Re: [PATCH] of/irq: Refer to actual buffer size in of_irq_parse_one()

[Rob Herring (Arm)]

On Tue, 20 Aug 2024 14:16:53 +0200, Geert Uytterhoeven wrote:
> Replace two open-coded calculations of the buffer size by invocations of
> sizeof() on the buffer itself, to make sure the code will always use the
> actual buffer size.
> 
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
> If you think this warrants a Fixes-tag:
> 
>     Fixes: b739dffa5d570b41 ("of/irq: Prevent device address out-of-bounds read in interrupt map walk")
> ---
>  drivers/of/irq.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 

Applied, thanks!