CVE-2023-53189: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: ipv6/addrconf: fix a potential refcount underflow for idev Now in addrconf_mod_rs_timer(), reference idev depends on whether rs_timer is not pending. Then modify rs_timer timeout. There is a time gap in [1], during which if the pending rs_timer becomes not pending. It will miss to hold idev, but the rs_timer is activated. Thus rs_timer callback function addrconf_rs_timer() will be executed and put idev later without holding idev. A refcount underflow issue for idev can be caused by this. if (!timer_pending(&idev->rs_timer)) in6_dev_hold(idev); <--------------[1] mod_timer(&idev->rs_timer, jiffies + when); To fix the issue, hold idev if mod_timer() return 0.

Affected products

• Linux Linux Kernel: from 3.10.105, before 4.14.322 (fixed in 4.14.322); from 4.15, before 4.19.291 (fixed in 4.19.291); from 4.20, before 5.4.251 (fixed in 5.4.251); from 5.5, before 5.10.188 (fixed in 5.10.188); from 5.11, before 5.15.121 (fixed in 5.15.121); from 5.16, before 6.1.40 (fixed in 6.1.40); …

Published 2025-09-15. Last modified 2026-08-04.