CVE-2026-31516

Summary

In the Linux kernel, the following vulnerability has been resolved:

xfrm: prevent policy_hthresh.work from racing with netns teardown

A XFRM_MSG_NEWSPDINFO request can queue the per-net work item policy_hthresh.work onto the system workqueue.

The queued callback, xfrm_hash_rebuild(), retrieves the enclosing struct net via container_of(). If the net namespace is torn down before that work runs, the associated struct net may already have been freed, and xfrm_hash_rebuild() may then dereference stale memory.

xfrm_policy_fini() already flushes policy_hash_work during teardown, but it does not synchronize policy_hthresh.work.

Synchronize policy_hthresh.work in xfrm_policy_fini() as well, so the queued work cannot outlive the net namespace teardown and access a freed struct net.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux880a6fab8f6ba5b5abe59ea68533202ddea1012c < 56ea2257b83ee29a543f158159e3d1abc1e3e4feaffected
LinuxLinux880a6fab8f6ba5b5abe59ea68533202ddea1012c < 8854e9367465d784046362698731c1111e3b39b8affected
LinuxLinux880a6fab8f6ba5b5abe59ea68533202ddea1012c < 4e2e77843fef473ef47e322d52436d8308582a96affected
LinuxLinux880a6fab8f6ba5b5abe59ea68533202ddea1012c < 29fe3a61bcdce398ee3955101c39f89c01a8a77eaffected
LinuxLinux3.18affected
LinuxLinux0 < 3.18unaffected
LinuxLinux6.12.80 <= 6.12.*unaffected
LinuxLinux6.18.21 <= 6.18.*unaffected
LinuxLinux6.19.11 <= 6.19.*unaffected
LinuxLinux7.0 <= *unaffected

Weaknesses

References