CVE-2025-37838 HSI: ssi_protocol: Fix use after free vulnerability in ssi_protocol Driver Due to Race Condition
A race condition in the Linux kernel HSI ssi_protocol driver allows a use-after-free, potentially enabling local attackers to execute code or escalate privileges.
- 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-2025-37838?
CVE-2025-37838 is a high-severity use after free vulnerability in Linux kernel, published on 18 Apr 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:
HSI: ssi_protocol: Fix use after free vulnerability in ssi_protocol Driver Due to Race Condition
In the ssi_protocol_probe() function, &ssi->work is bound with ssip_xmit_work(), In ssip_pn_setup(), the ssip_pn_xmit() function within the ssip_pn_ops structure is capable of starting the work.
If we remove the module which will call ssi_protocol_remove() to make a cleanup, it will free ssi through kfree(ssi), while the work mentioned above will be used. The sequence of operations that may lead to a UAF bug is as follows:
CPU0 CPU1
| ssip_xmit_work ssi_protocol_remove | kfree(ssi); | | struct hsi_client *cl = ssi->cl; | // use ssi
Fix it by ensuring that the work is canceled before proceeding with the cleanup in ssi_protocol_remove().
Weakness: CWE-416
Which versions are affected by CVE-2025-37838?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-37838?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2025-37838 being exploited?
There is no known exploitation of CVE-2025-37838 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2025-37838, DEBIAN-CVE-2025-37838, GHSA-m8p9-q552-5h79, ROOT-OS-UBUNTU-2204-CVE-2025-37838, ROOT-OS-UBUNTU-2404-CVE-2025-37838, UBUNTU-CVE-2025-37838.