HID: ft260: fix stack-use-after-return write in I2C read race
In the Linux kernel, the following vulnerability has been resolved: HID: ft260: fix stack-use-after-return write in I2C read race ft260_i2c_read() points dev->read_buf at a caller-supplied buffer (often an on-stack variable), arms a completion and waits up to five seconds for the device to return the data. The HID input callback ft260_raw_event() runs in the input/IRQ path, independent of the dev->lock mutex held by the read path, and copies the device-supplied payload into dev->read_buf after a plain NULL check. These two paths share read_buf, read_idx and read_len with no serialization. If the device delays its response until the read ti