CVE-2023-53189 ipv6/addrconf: fix a potential refcount underflow for idev
A race condition in the Linux kernel IPv6 address configuration can cause a reference count underflow, potentially leading to a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-53189?
CVE-2023-53189 is a high-severity vulnerability in Linux kernel, published on 15 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Weakness: CWE-191
Which versions are affected by CVE-2023-53189?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-53189?
Apply the vendor's patch.
Is CVE-2023-53189 being exploited?
There is no known exploitation of CVE-2023-53189 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2023-53189, DEBIAN-CVE-2023-53189, GHSA-4hgc-47xp-7m5f, UBUNTU-CVE-2023-53189.