batman-adv: dat: atomically update mac addresses

Summary

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.

Timeline

1. Sep 17, 2026, 4:12 PM UTCCVE published
2. Oct 19, 2026, 9:07 AM UTCRecord last updated

Affected versions

• Linux Linux

  From 2f1dfbe185075a50dc8f0490a136377af53a1c62 · fixed in 181012b3d29c51197c235ee5871fc7512c736855; From 2f1dfbe185075a50dc8f0490a136377af53a1c62 · fixed in 159360a0de831845c4500b4f8638decdcd624040; From 2f1dfbe185075a50dc8f0490a136377af53a1c62 · fixed in 259db2c04586d40b82c5c3002b1e28b0698a0bb7; From 2f1dfbe185075a50dc8f0490a136377af53a1c62 · fixed in 1674855a5b6eacfe35f4db3095d7055c25467274; From 2f1dfbe185075a50dc8f0490a136377af53a1c62 · fixed in 66238e2a74eca5dabf85b0cd2c3c944e474dc2fd; From 2f1dfbe185075a50dc8f0490a136377af53a1c62 · fixed in a5e4d6cb4f6848b8906c1c493f99a8ccc0638515; From 2f1dfbe185075a50dc8f0490a136377af53a1c62 · fixed in f68038c77a2f38c09c7e2e4f7fa1f4e246fdf2c9; From 2f1dfbe185075a50dc8f0490a136377af53a1c62 · fixed in e6de568d3eda3e3c01c868fabd7a9535d5ee4a73

• Linux Linux

  3.8

• KernelLinux

  From 3.8.0 · fixed in 5.10.271; From 5.11.0 · fixed in 5.15.221; From 5.16.0 · fixed in 6.1.188; From 6.2.0 · fixed in 6.6.157; From 6.7.0 · fixed in 6.12.110; From 6.13.0 · fixed in 6.18.52; From 6.19.0 · fixed in 7.2.6

References 8