CVE-2021-47382 s390/qeth: fix deadlock during failing recovery
A race condition in the s390/qeth driver can cause a deadlock during recovery, leading to a denial of service on Linux systems.
- 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-2021-47382?
CVE-2021-47382 is a medium-severity vulnerability in Linux kernel, published on 21 May 2024. 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:
s390/qeth: fix deadlock during failing recovery
Commit 0b9902c1fcc5 ("s390/qeth: fix deadlock during recovery") removed taking discipline_mutex inside qeth_do_reset(), fixing potential deadlocks. An error path was missed though, that still takes discipline_mutex and thus has the original deadlock potential.
Intermittent deadlocks were seen when a qeth channel path is configured offline, causing a race between qeth_do_reset and ccwgroup_remove. Call qeth_set_offline() directly in the qeth_do_reset() error case and then a new variant of ccwgroup_set_offline(), without taking discipline_mutex.
Which versions are affected by CVE-2021-47382?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2021-47382?
Apply the vendor's patch.
Is CVE-2021-47382 being exploited?
There is no known exploitation of CVE-2021-47382 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2021-47382, GHSA-q77h-85v7-m3mw, ROOT-OS-DEBIAN-11-CVE-2021-47382, UBUNTU-CVE-2021-47382.