CVE-2026-23001: macvlan: fix possible UAF in macvlan_forward_source()

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-01-25 · updated 2026-10-19
Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: macvlan: fix possible UAF in macvlan_forward_source() Add RCU protection on (struct macvlan_source_entry)->vlan. Whenever macvlan_hash_del_source() is called, we must clear entry->vlan pointer before RCU grace period starts. This allows macvlan_forward_source() to skip over entries queued for freeing. Note that macvlan_dev are already RCU protected, as they are embedded in a standard netdev (netdev_priv(ndev)). https: //lore.kernel.org/netdev/695fb1e8.050a0220.1c677c.039f.GAE@google.com/T/#u

Affected products

Linux kernel: from 3.18.1 before 5.10.249; from 5.11 before 5.15.199; from 5.16 before 6.1.162; from 6.2 before 6.6.122; from 6.7 before 6.12.67; from 6.13 before 6.18.7 — fixed in 5.10.249, 5.15.199, 6.1.162, 6.12.67, 6.18.7, 6.6.122

How to fix

Upgrade to a fixed version: Linux kernel 5.10.249, 5.15.199, 6.1.162, 6.12.67. Check the vendor advisory for mitigations.

References

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