HID: mcp2221: Set driver data before I2C adapter add

commit f2d4a58346 upstream.

The process of adding an I2C adapter can invoke I2C accesses on that new
adapter (see i2c_detect()).

Ensure we have set the adapter's driver data to avoid null pointer
dereferences in the xfer functions during the adapter add.

This has been noted in the past and the same fix proposed but not
completed. See:
https://lore.kernel.org/lkml/ef597e73-ed71-168e-52af-0d19b03734ac@vigem.de/

Signed-off-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Sumanth Gavini <sumanth.gavini@yahoo.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Hamish Martin 2023-10-25 16:55:10 +13:00 committed by Greg Kroah-Hartman
parent 7c2a7b776d
commit 0499d5d579

View File

@ -879,12 +879,12 @@ static int mcp2221_probe(struct hid_device *hdev,
snprintf(mcp->adapter.name, sizeof(mcp->adapter.name),
"MCP2221 usb-i2c bridge");
i2c_set_adapdata(&mcp->adapter, mcp);
ret = i2c_add_adapter(&mcp->adapter);
if (ret) {
hid_err(hdev, "can't add usb-i2c adapter: %d\n", ret);
goto err_i2c;
}
i2c_set_adapdata(&mcp->adapter, mcp);
/* Setup GPIO chip */
mcp->gc = devm_kzalloc(&hdev->dev, sizeof(*mcp->gc), GFP_KERNEL);