CVE-2026-68415

CVE-2026-68415 · xfrm: clear mode callbacks after failed mode setup

CVSS 7.8 · High · EPSS 0.1% · Fix available

dpkg-query -W -f='${source:Package} ${binary:Package} ${Version}\n' | awk '$1=="linux"'

dpkg-query -W -f='${source:Package} ${binary:Package} ${Version}\n' | awk '$1=="linux-hwe-edge"'

dpkg-query -W -f='${source:Package} ${binary:Package} ${Version}\n' | awk '$1=="linux-aws-5.0"'

curl -fsSL https://patchfirst.dev/check.sh | sh

This page contains facts from public vulnerability sources. Check the original advisory before updating.

This page shows selected source facts. See the linked advisories for the complete description and affected versions.

In the Linux kernel, the following vulnerability has been resolved: xfrm: clear mode callbacks after failed mode setup xfrm_state_gc_task can run long after a failed IPTFS state setup. In the reproduced case, __xfrm_init_state() cached x->mode_cbs, IPTFS setup returned -ENOMEM before publishing mode_data, and the temporary module reference from xfrm_get_mode_cbs() was dropped immediately. The dead state then kept x->mode_cbs until deferred GC ran after xfrm_iptfs had been unloaded. Clear x->mode_cbs when mode init or clone fails before publishing mode_data. Those states never installed mode-specific state or the long-term IPTFS module pin, so deferred GC has nothing mode-specific to destroy and must not retain a callback table pointer past the temporary lookup reference. The buggy scenario involves two paths, with each column showing the order within that path: failed setup path: 1. cache x->mode_cbs 2. mode setup fails before mode_data 3. drop the temporary module ref 4. dead state keeps x->mode_cbs cached GC/unload path: 1. xfrm_state_put() queues GC work 2. xfrm_iptfs unloads later 3. xfrm_state_gc_task runs 4. GC dereferences stale x->mode_cbs This also covers the failed clone path where clone_state() returns before publishing mode_data. Validation reproduced this kernel report: Kernel panic - not syncing: Fatal exception CONFIG_FAULT_INJECTION_STACKTRACE_FILTER=y failslab_stacktrace_filter matched xfrm_iptfs frames ack_error=-12 FAULT_INJECTION: forcing a failure BUG: unable to handle page fault Workqueue: events xfrm_state_gc_task RIP: xfrm_state_gc_task+0x142/0x650 Modules linked in: esp4_offload xfrm_user [last unloaded: xfrm_iptfs] Kernel panic - not syncing: Fatal exception

Published

2026-08-10T12:04:35.425Z

Updated

2026-08-17T05:05:09.173Z

Stack: system

Check your server →