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.
No analysis available yet.
No remediation available yet.
Tracking
Sign in to view the affected projects.
No advisories yet.
Tue, 17 Mar 2026 21:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-416 | |
| Metrics |
cvssV3_1
|
cvssV3_1
|
Thu, 05 Mar 2026 00:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Wed, 04 Mar 2026 13:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Wed, 04 Mar 2026 13:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | netfilter: nf_tables: fix use-after-free in nf_tables_addchain() | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-04-02T14:43:50.891Z
Reserved: 2026-01-13T15:37:45.988Z
Link: CVE-2026-23231
No data.
Status : Modified
Published: 2026-03-04T13:15:58.137
Modified: 2026-04-02T15:16:24.693
Link: CVE-2026-23231
OpenCVE Enrichment
Updated: 2026-03-04T21:03:32Z