CVE-2026-93204

About vulnerability

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

batman-adv: dat: atomically update mac addresses

When a MAC address is updated in batadv_dat_entry_add(), it is done using a simple copy function. A parallel reader might only see parts of this update. In worst case, the reader is transporting the half updated MAC address over the network or is creating an ARP response using it - poisoning the ARP cache.

atomic64_t can be used to store the 48 bit of a mac address. A reader will then either see the old mac address or the new one - never a mixture of both.

Affected product:

AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 7 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS

Affected packages:

linux @ 5.4.0 (+17 more)

Live-patch status from KernelCare for each operating system.