i2c: cp2615: fix serial string NULL-deref at probe

The cp2615 driver uses the USB device serial string as the i2c adapter
name but does not make sure that the string exists.

Verify that the device has a serial number before accessing it to avoid
triggering a NULL-pointer dereference (e.g. with malicious devices).

Fixes: 4a7695429ead ("i2c: cp2615: add i2c driver for Silicon Labs' CP2615 Digital Audio Bridge")
Cc: stable@vger.kernel.org	# 5.13
Cc: Bence Csókás <bence98@sch.bme.hu>
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Bence Csókás <bence98@sch.bme.hu>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260309075016.25612-1-johan@kernel.org

diff --git a/drivers/i2c/busses/i2c-cp2615.c b/drivers/i2c/busses/i2c-cp2615.c
index e2d7cd2390fc4a0a4e7a48c88651f727a4cc68c3..8212875700e15d1fefe051d8697a80f65884d8da 100644 (file)
--- a/drivers/i2c/busses/i2c-cp2615.c
+++ b/drivers/i2c/busses/i2c-cp2615.c
@@ -298,6 +298,9 @@ cp2615_i2c_probe(struct usb_interface *usbif, const struct usb_device_id *id)
        if (!adap)
                return -ENOMEM;
 
+       if (!usbdev->serial)
+               return -EINVAL;
+
        strscpy(adap->name, usbdev->serial, sizeof(adap->name));
        adap->owner = THIS_MODULE;
        adap->dev.parent = &usbif->dev;