CVE-2026-80780 HID: pidff: fix OOB write when hid->inputs is empty
A malicious USB device can trigger an out-of-bounds write in the Linux kernel HID driver, potentially allowing code execution or privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-80780?
CVE-2026-80780 is a memory corruption vulnerability in Linux, published on 4 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
In the Linux kernel, the following vulnerability has been resolved:
HID: pidff: fix OOB write when hid->inputs is empty
hid_pidff_init_with_quirks() derives its input_dev from
list_entry(hid->inputs.next, struct hid_input, list)
without first checking that hid->inputs is non-empty. The list member of struct hid_input is at offset 0, so on an empty list list_entry() yields &hid->inputs itself and the following hidinput->input load reads an unrelated member of struct hid_device. dev is then a type-confused pointer, and force-feedback init writes through it: each set_bit(FF_*, dev->ffbit) stores 8 bytes at dev + 192, past the end of the object dev actually aliases, and input_ff_create() adds further writes of a heap pointer and two function pointers.
Until hid-universal-pidff the only caller was hid_pidff_init() from usbhid, which runs under HID_CLAIMED_INPUT and therefore always has at least one hid_input. universal_pidff_probe() starts the device with HID_CONNECT_DEFAULT & ~HID_CONNECT_FF and then calls hid_pidff_init_with_quirks() directly whenever the descriptor carries a PID usage page, bypassing that gate. A report descriptor whose only application collection is on HID_UP_PID leaves hid->inputs empty while hid_connect() still succeeds through the hidraw claim, so probe reaches the unguarded list_entry().
The write happens in the USB probe path, on the hotplug workqueue, so plugging in a malicious device is enough to trigger it; no attacker software and no logged-in user are required. KASAN reports an 8-byte out-of-bounds write in hid_pidff_init_with_quirks() reached from universal_pidff_probe().
Check for an empty list before deriving dev and return -ENODEV, as the other HID force-feedback drivers already do. universal_pidff_probe() propagates the error and unwinds.
Discovered by XBOW, triaged by Baul Lee <[email protected]>
Which versions are affected by CVE-2026-80780?
How do I fix CVE-2026-80780?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-80780 being exploited?
There is no known exploitation of CVE-2026-80780 in the wild and no public exploit code.
Sources
Also known as AZL-99650, BELL-CVE-2026-80780, DEBIAN-CVE-2026-80780, GHSA-rxff-7rcf-x4wj, UBUNTU-CVE-2026-80780.