CVE-2023-53620 md: fix soft lockup in status_resync
A race condition in the Linux kernel's md driver can cause a soft lockup during resync operations, 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-2023-53620?
CVE-2023-53620 is a medium-severity denial of service vulnerability in Linux kernel, published on 7 Oct 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:
md: fix soft lockup in status_resync
status_resync() will calculate 'curr_resync - recovery_active' to show user a progress bar like following:
[============>........] resync = 61.4%
'curr_resync' and 'recovery_active' is updated in md_do_sync(), and status_resync() can read them concurrently, hence it's possible that 'curr_resync - recovery_active' can overflow to a huge number. In this case status_resync() will be stuck in the loop to print a large amount of '=', which will end up soft lockup.
Fix the problem by setting 'resync' to MD_RESYNC_ACTIVE in this case, this way resync in progress will be reported to user.
Weakness: CWE-667
Which versions are affected by CVE-2023-53620?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-53620?
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-2023-53620 being exploited?
There is no known exploitation of CVE-2023-53620 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-76641, BELL-CVE-2023-53620, DEBIAN-CVE-2023-53620, GHSA-gjrx-w6pw-88ph, ROOT-OS-DEBIAN-11-CVE-2023-53620, ROOT-OS-UBUNTU-2204-CVE-2023-53620 and 1 more.