CVE-2023-54306 net: tls: avoid hanging tasks on the tx_lock
An adversarial receiver can cause Linux kernel tasks to hang indefinitely by keeping the receive window at zero, leading to a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-54306?
CVE-2023-54306 is a high-severity denial of service vulnerability in Linux, published on 30 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
net: tls: avoid hanging tasks on the tx_lock
syzbot sent a hung task report and Eric explains that adversarial receiver may keep RWIN at 0 for a long time, so we are not guaranteed to make forward progress. Thread which took tx_lock and went to sleep may not release tx_lock for hours. Use interruptible sleep where possible and reschedule the work if it can't take the lock.
Testing: existing selftest passes
Which versions are affected by CVE-2023-54306?
How do I fix CVE-2023-54306?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2023-54306 being exploited?
There is no known exploitation of CVE-2023-54306 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-54306, DEBIAN-CVE-2023-54306, GHSA-f7xx-6pgx-v4hg, UBUNTU-CVE-2023-54306.