CVE-2026-43091
Published: May 7, 2026Last modified: May 7, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: xfrm: Wait for RCU readers during policy netns exit xfrm_policy_fini() 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 policy_bydst tables are published via rcu_assign_pointer() and are looked up through rcu_dereference_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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.8 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Vulnerable (6.1.170-r0) |
| 25 LTS | linux-lts | Fixed (6.12.85-r0) | |
| Stream | linux-lts | Fixed (6.12.85-r0) |
References
- https://git.kernel.org/stable/c/069daad4f2ae9c5c108131995529d5f02392c446
- https://git.kernel.org/stable/c/33a3149dd81a1e2f52b80ee1e0fc380b39f3d028
- https://git.kernel.org/stable/c/3733fce2871c9bca9dd18a1a23b1432ea215a094
- https://git.kernel.org/stable/c/438b1f668ad58f46ce699bb48e4698a7839e3f9e
- https://git.kernel.org/stable/c/b66920a3348c0f63ba18365248fa21fbf0b3a937