netfilter: flowtable: publish GC-visible tuple last

Summary

In the Linux kernel, the following vulnerability has been resolved: netfilter: flowtable: publish GC-visible tuple last nf_flow_table_iterate() only treats original-direction tuple nodes as owning entries. Publishing the original node first lets GC observe and free a flow while flow_offload_add() is still inserting the reply node. Publish the reply node first and the original node last so GC never sees a partially installed flow. KASAN can trigger slab-use-after-free read and write reports in the flowtable/rhashtable path (rht_deferred_worker, jhash, flow_offload_del, flow_offload_lookup, etc.).

Timeline

1. Aug 26, 2026, 2:36 PM UTCCVE published
2. Oct 16, 2026, 7:16 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: yes · Technical impact: total

3. Oct 16, 2026, 7:26 PM UTCRecord last updated

Affected versions

• Linux Linux

  From ac2a66665e231847cab11b8c8e844ce43207dd2e · fixed in 0a00254585827f1695aa2700114af622ea754cfa; From ac2a66665e231847cab11b8c8e844ce43207dd2e · fixed in be345dcbddb4643a54252b954af974b16eda8f91; From ac2a66665e231847cab11b8c8e844ce43207dd2e · fixed in 211ee5d998d92a7d548811939c65942d06c146e4; From ac2a66665e231847cab11b8c8e844ce43207dd2e · fixed in d37917e7bebe078f3c17e47fd6fc1c9f6e8497b2; From ac2a66665e231847cab11b8c8e844ce43207dd2e · fixed in 972fdf7c4f5c282a239c88fea614b056c33dc025; From ac2a66665e231847cab11b8c8e844ce43207dd2e · fixed in d9d3050a70efe217e73a0751e55fdae6a7092620; From ac2a66665e231847cab11b8c8e844ce43207dd2e · fixed in d16b71231e65cb05daea2b45701fcf09cef041e7; From ac2a66665e231847cab11b8c8e844ce43207dd2e · fixed in 2014ac62df9d45bb9a004a043e85df7be09ed780

• Linux Linux

  4.16

• KernelLinux

  From 4.16.0 · fixed in 5.10.266; From 5.11.0 · fixed in 5.15.217; From 5.16.0 · fixed in 6.1.184; From 6.2.0 · fixed in 6.6.153; From 6.7.0 · fixed in 6.12.105; From 6.13.0 · fixed in 6.18.46; From 6.19.0 · fixed in 7.1.10

References 8