CVE-2026-98929
Received
Received - Intake
MACsec Device Registration Ordering Flaw in Linux Kernel
Vulnerability report for CVE-2026-98929, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-23
Last updated on: 2026-10-23
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
macsec: initialize SecY before registering the netdevice
Creating a MACsec device with MAC offload over an LRO-capable lower
device triggers a warning in rtmsg_ifinfo_build_skb() when IPv4
forwarding is enabled by default.
register_netdevice() invokes inetdev_init(), which disables LRO and emits
a NETDEV_FEAT_CHANGE notification. This reaches macsec_fill_info() before
macsec_add_dev() initializes the SecY. key_len is still zero, so
macsec_fill_info() returns -EMSGSIZE and trips the WARN_ON in
rtmsg_ifinfo_build_skb(), even though the skb has enough space.
Even without the warning, notifications during registration can report
uninitialized SecY attributes, including the SCI. This ordering has existed
since the driver was introduced.
Initialize the SecY and apply the new-link attributes before registration.
Move MAC address inheritance into macsec_newlink() so the SCI can also be
initialized before registration-time notifications report it. Move the
per-CPU statistics and metadata destination allocation into ndo_init(),
and release partial allocations on failure.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
