Skip to content
CVE Ledger
  • Newest CVEsPage
  • Recently added to KEVPage
  • Rising exploitation (EPSS)Page
  • Weekly digestPage
  • StatisticsPage
  • WatchlistPage
  • API docsPage
  • MCP serverPage
  • AboutPage
  • Data sourcesPage
  • Data statusPage
  • ChangelogPage
  • How it's builtPage
  • Support the projectPage

14 results

Back

CVE-2026-64525xfrm: move policy_bydst RCU sync from per-netns .exit to .pre_exit

Description

In the Linux kernel, the following vulnerability has been resolved: xfrm: move policy_bydst RCU sync from per-netns .exit to .pre_exit The struct pernet_operations docstring in include/net/net_namespace.h explicitly warns against blocking RCU primitives in .exit handlers: Exit methods using blocking RCU primitives, such as synchronize_rcu(), should be implemented via exit_batch. [...] Please, avoid synchronize_rcu() at all, where it's possible. Note that a combination of pre_exit() and exit() can be used, since a synchronize_rcu() is guaranteed between the calls. xfrm_policy_fini() violates this: it calls synchronize_rcu() before freeing the policy_bydst hash tables (so no RCU reader is mid- traversal at free time), but runs from xfrm_net_ops.exit -- once per namespace -- so a cleanup_net() of N namespaces pays N full RCU grace periods serially. Use the documented pre_exit/exit split. Move the policy flush (and the workqueue drains it depends on) into a new .pre_exit handler; xfrm_policy_fini() then runs in .exit and frees the hash tables after the synchronize_rcu_expedited() that cleanup_net() guarantees between the two phases. Providing O(1) RCU grace periods per batch instead of O(N). Observed on Linux 6.18 with a workload doing unshare(CLONE_NEWNET) at ~13/sec sustained: cleanup_net() and the netns_wq rescuer kthread both stuck in xfrm_policy_fini()'s synchronize_rcu(), >300k struct net accumulated in the cleanup queue, Percpu in /proc/meminfo climbed to 130+ GB on 256-CPU hosts, and memcg OOMs followed. setup_net and __put_net counts were balanced, ruling out a refcount leak.

Timeline

  1. ID reserved

    By Linux

  2. · 6 days later

    Published

  3. · 3 months later

    Record updated

Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.

Scores

No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Awaiting Analysis.

EPSS (exploitation in 30 days)
0.16% · top 95% of all CVEs (13 Nov 2026)
Loading the EPSS history…

The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.

Affected products

  • Linux · Linux

    • affected 438b1f668ad58f46ce699bb48e4698a7839e3f9e – < bca6386dc08750fc7cdcbc7683473748ba3114b9
    • affected 3733fce2871c9bca9dd18a1a23b1432ea215a094 – < 91cc13978ab0bc6f669139f53e7e613a860d10e0
    • affected 069daad4f2ae9c5c108131995529d5f02392c446 – < d14ae8ef88c2c6590e107db61b6adce148cec7b3
    • affected 069daad4f2ae9c5c108131995529d5f02392c446 – < 3e52417318473782012b236d0325bf7d2266a597
    • affected b2faee12538b5b008eaef65a4201eb29cb5cefb3
    • affected b66920a3348c0f63ba18365248fa21fbf0b3a937
    • affected 33a3149dd81a1e2f52b80ee1e0fc380b39f3d028
    • affected 6.12.83 – < 6.12.93
    • affected 6.18.24 – < 6.18.35
    • affected 6.1.191 – < 6.2
    • affected 6.6.136 – < 6.7
    • affected 6.19.14 – < 6.20

  • Linux · Linux

    • affected 7.0
    • unaffected < 7.0
    • unaffected 6.12.93 – ≤ 6.12.*
    • unaffected 6.18.35 – ≤ 6.18.*
    • unaffected 7.0.12 – ≤ 7.0.*
    • unaffected 7.1 – ≤ *

References

References4

Sources

The same CVE in the primary databases and aggregators, to check against.

Badge for a README or a ticket

CVE-2026-64525 badge
[![CVE-2026-64525](https://cveledger.app/badge/CVE-2026-64525.svg)](https://cveledger.app/cve/CVE-2026-64525)

Record last updated .