CVE-2025-38549 efivarfs: Fix memory leak of efivarfs_fs_info in fs_context error paths
A memory leak in the Linux kernel's efivarfs filesystem can lead to resource exhaustion and 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-2025-38549?
CVE-2025-38549 is a medium-severity denial of service vulnerability in Linux kernel, published on 16 Aug 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:
efivarfs: Fix memory leak of efivarfs_fs_info in fs_context error paths
When processing mount options, efivarfs allocates efivarfs_fs_info (sfi) early in fs_context initialization. However, sfi is associated with the superblock and typically freed when the superblock is destroyed. If the fs_context is released (final put) before fill_super is called—such as on error paths or during reconfiguration—the sfi structure would leak, as ownership never transfers to the superblock.
Implement the .free callback in efivarfs_context_ops to ensure any allocated sfi is properly freed if the fs_context is torn down before fill_super, preventing this memory leak.
Weakness: CWE-401
Which versions are affected by CVE-2025-38549?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-38549?
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-2025-38549 being exploited?
There is no known exploitation of CVE-2025-38549 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2025-38549, DEBIAN-CVE-2025-38549, GHSA-cgrx-9qvf-wh88, ROOT-OS-UBUNTU-2404-CVE-2025-38549, UBUNTU-CVE-2025-38549.