Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
HID: core: quiesce input in hid_hw_stop() to prevent use-after-free
A driver’s probe calls hid_device_io_start() to enable input delivery, then fails at a later initialization step and unwinds via hid_hw_stop(). The unwind frees struct hidraw via hidraw_disconnect() while in-flight HID reports may still be running on another CPU, dereferencing the freed object through hidraw_report_event(). syzbot reports the resulting use-after-free for the corsair-psu HID driver.
Edward Adam Davis posted a per-driver fix for corsair-psu that adds an explicit hid_device_io_stop() before hid_hw_stop() in the probe error path (“hwmon: prevent packets from going to driver for probe”, 2026-04-28). Auditing the tree shows 15 drivers call hid_device_io_start(); 7 also call hid_device_io_stop() and 8 do not:
drivers calling hid_device_io_start() without a matching hid_device_io_stop() before hid_hw_stop(): drivers/hwmon/corsair-psu.c (fix posted by Edward) drivers/hwmon/corsair-cpro.c drivers/hwmon/nzxt-kraken3.c drivers/hwmon/nzxt-smart2.c drivers/hwmon/gigabyte_waterforce.c drivers/hid/hid-logitech-dj.c drivers/hid/hid-nintendo.c drivers/hid/hid-mcp2221.c
Roughly half of all callers of the API are exposed. Centralize the quiesce in hid_hw_stop() so callers do not have to remember the matching stop: if a driver has left hdev->io_started true on entry, call hid_device_io_stop() before hid_disconnect().
For the 7 drivers that already call hid_device_io_stop() correctly, hdev->io_started is false on entry, the guard short-circuits, and behavior is unchanged.
No Fixes: tag because the affected drivers gained their hid_device_io_start() calls independently over years; the bug is a class-wide API misuse rather than a regression from one commit.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 6 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 7 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 6 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.4.0 (+19 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| CentOS 7 ELS | Planned | — |
| Debian 12 | Planned | — |
| Debian 13 | Planned | — |