CVE-2026-80768

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

times out, ft260_i2c_read() resets the controller, clears read_buf

and returns, unwinding the stack frame the buffer lived in. A

response that arrives at that moment lets ft260_raw_event() pass the

NULL check and then memcpy() the device-controlled payload into the

now-freed stack location, a bounded but attacker-influenced

stack-use-after-return write triggerable by malicious or

malfunctioning hardware.

Add a dedicated spinlock that serializes every access to read_buf,

read_idx and read_len. ft260_raw_event() now holds it across the

NULL check, the memcpy and the index update, while the read path

takes it when arming and when clearing the buffer, so the teardown

can no longer slip between the check and the copy.