CVE-2021-47500: iio: mma8452: Fix trigger reference couting

Severity: high (CVSS 7.8 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: 2024-05-24 · updated 2026-08-04
Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: iio: mma8452: Fix trigger reference couting The mma8452 driver directly assigns a trigger to the struct iio_dev. The IIO core when done using this trigger will call `iio_trigger_put()` to drop the reference count by 1. Without the matching `iio_trigger_get()` in the driver the reference count can reach 0 too early, the trigger gets freed while still in use and a use-after-free occurs. Fix this by getting a reference to the trigger before assigning it to the IIO device.

Affected products

Linux kernel: from 4.2 before 4.4.295; from 4.5 before 4.9.293; from 4.10 before 4.14.258; from 4.15 before 4.19.221; from 4.20 before 5.4.165; from 5.5 before 5.10.85 — fixed in 4.14.258, 4.19.221, 4.4.295, 4.9.293, 5.10.85, 5.15.8

How to fix

Upgrade to a fixed version: Linux kernel 4.14.258, 4.19.221, 4.4.295, 4.9.293. Check the vendor advisory for mitigations.

References

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