CVE-2021-46932: Input: appletouch - initialize work before device registration

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-02-27 · updated 2026-06-17
Weakness: CWE-665

Description

In the Linux kernel, the following vulnerability has been resolved: Input: appletouch - initialize work before device registration Syzbot has reported warning in __flush_work(). This warning is caused by work->func == NULL, which means missing work initialization. This may happen, since input_dev->close() calls cancel_work_sync(&dev->work), but dev->work initalization happens _after_ input_register_device() call. So this patch moves dev->work initialization before registering input device

Affected products

Linux kernel: from 2.6.23 before 4.4.298; from 4.5.0 before 4.9.296; from 4.10.0 before 4.14.261; from 4.15.0 before 4.19.224; from 4.20.0 before 5.4.170; from 5.5.0 before 5.10.90 — fixed in 4.14.261, 4.19.224, 4.4.298, 4.9.296, 5.10.90, 5.15.13

How to fix

Upgrade to a fixed version: Linux kernel 4.14.261, 4.19.224, 4.4.298, 4.9.296. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2021-46932 or the next vulnerability affects your stack