CVE-2026-43091

xfrmpolicyfini() frees the policy_bydst hash tables after flushing the policy work items and deleting all policies, but it does not wait for concurrent RCU readers to leave their read-side critical sections first.

The policybydst tables are published via rcuassignpointer() and are looked up through rcudereference_check(), so netns teardown must also wait for an RCU grace period before freeing the table memory.

Fix this by adding synchronize_rcu() before freeing the policy hash tables.

Database specific

{
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43091.json",
    "cna_assigner": "Linux"
}

References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type: GIT
Repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events: Introduced

e1e551bc56302b80ff930c966f9985095fb1b70d

Fixed

b66920a3348c0f63ba18365248fa21fbf0b3a937

Fixed

438b1f668ad58f46ce699bb48e4698a7839e3f9e

Fixed

3733fce2871c9bca9dd18a1a23b1432ea215a094

Fixed

33a3149dd81a1e2f52b80ee1e0fc380b39f3d028

Fixed

069daad4f2ae9c5c108131995529d5f02392c446

Database specific

source

"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-43091.json"

Linux / Kernel

Package

Name: Kernel

Affected ranges

Type: ECOSYSTEM
Events: Introduced

4.9.0

Fixed

6.6.136

Type: ECOSYSTEM
Events: Introduced

6.7.0

Fixed

6.12.83

Type: ECOSYSTEM
Events: Introduced

6.13.0

Fixed

6.18.24

Type: ECOSYSTEM
Events: Introduced

6.19.0

Fixed

6.19.14

Database specific

source

"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-43091.json"