[PATCH] i2c: mark HostNotify target address as used

From: Wolfram Sang
Date: Wed Jul 10 2024 - 04:57:31 EST


I2C core handles the local target for receiving HostNotify alerts. There
is no separate driver bound to that address. That means userspace can
access it if desired, leading to further complications if controllers
are not capable of reading their own local target. Bind the local target
to the dummy driver so it will marked as "handled by the kernel" if the
HostNotify feature is used. That protects aginst userspace access and
prevents other drivers binding to it.

Fixes: 2a71593da34d ("i2c: smbus: add core function handling SMBus host-notify")
Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
---
drivers/i2c/i2c-core-base.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index d6213d251336..57f03cbb1f48 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1067,6 +1067,7 @@ EXPORT_SYMBOL(i2c_find_device_by_fwnode);

static const struct i2c_device_id dummy_id[] = {
{ "dummy" },
+ { "smbus_host_notify" },
{ }
};

--
2.43.0