Bug 2444376 (CVE-2026-23231)
| Summary: | CVE-2026-23231 kernel: kernel: Privilege escalation or denial of service via use-after-free in nf_tables_addchain() | ||
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| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | Keywords: | Security |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | --- | |
| Doc Text: |
A flaw was found in the Linux kernel. A local attacker with CAP_NET_ADMIN capabilities, or remote packet traffic, could exploit a use-after-free vulnerability in the nf_tables_addchain() function's error handling. Successful exploitation could lead to a kernel crash, resulting in a Denial of Service (DoS), or potentially privilege escalation.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
Upstream advisory: https://lore.kernel.org/linux-cve-announce/2026030436-CVE-2026-23231-1a96@gregkh/T This issue has been addressed in the following products: Red Hat Enterprise Linux 10 Via RHSA-2026:6053 https://access.redhat.com/errata/RHSA-2026:6053 This issue has been addressed in the following products: Red Hat Enterprise Linux 9 Via RHSA-2026:6570 https://access.redhat.com/errata/RHSA-2026:6570 This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2026:6572 https://access.redhat.com/errata/RHSA-2026:6572 This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2026:6571 https://access.redhat.com/errata/RHSA-2026:6571 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.6 Extended Update Support Via RHSA-2026:6940 https://access.redhat.com/errata/RHSA-2026:6940 This issue has been addressed in the following products: Red Hat Enterprise Linux 10.0 Extended Update Support Via RHSA-2026:9095 https://access.redhat.com/errata/RHSA-2026:9095 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions Via RHSA-2026:9512 https://access.redhat.com/errata/RHSA-2026:9512 This issue has been addressed in the following products: Red Hat Enterprise Linux 8.2 Advanced Update Support Via RHSA-2026:9513 https://access.redhat.com/errata/RHSA-2026:9513 This issue has been addressed in the following products: Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions Red Hat Enterprise Linux 8.8 Telecommunications Update Service Via RHSA-2026:9515 https://access.redhat.com/errata/RHSA-2026:9515 This issue has been addressed in the following products: Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions Red Hat Enterprise Linux 8.6 Telecommunications Update Service Via RHSA-2026:9514 https://access.redhat.com/errata/RHSA-2026:9514 This issue has been addressed in the following products: Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On Via RHSA-2026:9643 https://access.redhat.com/errata/RHSA-2026:9643 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions Via RHSA-2026:9644 https://access.redhat.com/errata/RHSA-2026:9644 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions Via RHSA-2026:9835 https://access.redhat.com/errata/RHSA-2026:9835 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions Via RHSA-2026:9836 https://access.redhat.com/errata/RHSA-2026:9836 This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Extended Lifecycle Support Via RHSA-2026:9870 https://access.redhat.com/errata/RHSA-2026:9870 This issue has been addressed in the following products: Red Hat Enterprise Linux 9.4 Extended Update Support Via RHSA-2026:10108 https://access.redhat.com/errata/RHSA-2026:10108 This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Extended Lifecycle Support Via RHSA-2026:10756 https://access.redhat.com/errata/RHSA-2026:10756 |
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: fix use-after-free in nf_tables_addchain() nf_tables_addchain() publishes the chain to table->chains via list_add_tail_rcu() (in nft_chain_add()) before registering hooks. If nf_tables_register_hook() then fails, the error path calls nft_chain_del() (list_del_rcu()) followed by nf_tables_chain_destroy() with no RCU grace period in between. This creates two use-after-free conditions: 1) Control-plane: nf_tables_dump_chains() traverses table->chains under rcu_read_lock(). A concurrent dump can still be walking the chain when the error path frees it. 2) Packet path: for NFPROTO_INET, nf_register_net_hook() briefly installs the IPv4 hook before IPv6 registration fails. Packets entering nft_do_chain() via the transient IPv4 hook can still be dereferencing chain->blob_gen_X when the error path frees the chain. Add synchronize_rcu() between nft_chain_del() and the chain destroy so that all RCU readers -- both dump threads and in-flight packet evaluation -- have finished before the chain is freed.