CVE-2025-39901

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

i40e: remove read access to debugfs files

The 'command' and 'netdev_ops' debugfs files are a legacy debugging

interface supported by the i40e driver since its early days by commit

02e9c290814c ("i40e: debugfs interface").

Both of these debugfs files provide a read handler which is mostly useless,

and which is implemented with questionable logic. They both use a static

256 byte buffer which is initialized to the empty string. In the case of

the 'command' file this buffer is literally never used and simply wastes

space. In the case of the 'netdev_ops' file, the last command written is

saved here.

On read, the files contents are presented as the name of the device

followed by a colon and then the contents of their respective static

buffer. For 'command' this will always be "<device>: ". For 'netdev_ops',

this will be "<device>: <last command written>". But note the buffer is

shared between all devices operated by this

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References