CVE Catalog

CVE-2026-53013

MediumCVSS 5.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.17%

6th percentile - higher than 6% of all known CVEs

Summary

In the Linux kernel's macvlan driver, the macvlan_get_size() function does not reserve space for the IFLA_MACVLAN_BC_CUTOFF attribute. This causes -EMSGSIZE errors and a WARN_ON in rtnetlink when dumping the interface if bc_cutoff is set to a value other than 1.

Risk Assessment

Organizations may face issues managing macvlan interfaces, especially when using tools like ip that rely on Netlink dumps. This can hinder network diagnostics and configuration automation.

Recommendation

Apply the Linux kernel patch that adds the missing nla_total_size(4) in macvlan_get_size(). Update the kernel to a version containing this fix.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: macvlan: fix macvlan_get_size() not reserving space for IFLA_MACVLAN_BC_CUTOFF macvlan_get_size() does not account for IFLA_MACVLAN_BC_CUTOFF, but macvlan_fill_info() conditionally includes it when port->bc_cutoff != 1. This causes nla_put_s32() to fail with -EMSGSIZE when the netlink skb runs out of space, triggering a WARN_ON in rtnetlink and preventing the interface from being dumped. The bug can be reproduced with: ip link add macvlan0 link eth0 type macvlan mode bridge ip link set macvlan0 type macvlan bc_cutoff 0 ip -d link show macvlan0 # fails with -EMSGSIZE The bc_cutoff feature was added in commit 954d1fa1ac93 ("macvlan: Add netlink attribute for broadcast cutoff"), which added the nla_put_s32() call in macvlan_fill_info() but missed adding the corresponding nla_total_size(4) in macvlan_get_size(). A follow-up commit 55cef78c244d ("macvlan: add forgotten nla_policy for IFLA_MACVLAN_BC_CUTOFF") fixed the missing nla_policy entry but still did not fix the size calculation.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS