CVE-2026-43090: xfrm: fix refcount leak in xfrm_migrate_policy_find
In the Linux kernel, the following vulnerability has been resolved:
xfrm: fix refcount leak in xfrmmigratepolicyfind
syzkaller reported a memory leak in xfrmpolicyalloc:
BUG: memory leak unreferenced object 0xffff888114d79000 (size 1024): comm "syz.1.17", pid 931 ... xfrmpolicyalloc+0xb3/0x4b0 net/xfrm/xfrmpolicy.c:432
The root cause is a double call to xfrmpolholdrcu() in xfrmmigratepolicyfind(). The lookup function already returns a policy with held reference, making the second call redundant.
Remove the redundant xfrmpolholdrcu() call to fix the refcount imbalance and prevent the memory leak.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Affected Software
Remediation
Event History
Frequently Asked Questions
What access does an attacker need to exploit this issue?
The CVSS vector indicates local access and low privileges are required. No user interaction is required.
What is the practical impact if exploited?
The issue can cause a memory leak through an xfrm policy reference-count imbalance, which can lead to availability impact. The CVSS vector rates availability impact as high, with no confidentiality or integrity impact.
How can this be remediated?
Apply the available Linux kernel patch. The fix removes a redundant xfrm_pol_hold_rcu() call in xfrm_migrate_policy_find() that caused the reference-count leak.