CVE-2025-40279

/// Technical description

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

net: sched: act_connmark: initialize struct tc_ife to fix kernel leak

In tcf_connmark_dump(), the variable 'opt' was partially initialized using a

designatied initializer. While the padding bytes are reamined

uninitialized. nla_put() copies the entire structure into a

netlink message, these uninitialized bytes leaked to userspace.

Initialize the structure with memset before assigning its fields

to ensure all members and padding are cleared prior to beign copied.

/// 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