Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
Linux Linux — netfilter: nf_tables: do not defer rule destruction via call_rcu
AV AC PR UI S C I A CVSS EPSS %ile KEV
L L L N U N N H 5.5 .0023 13.6 —
AFFECTED
Product Versions Fixed
Linux 9eee6097ffb26cdd2adb988c0d378fa0d650c737 – —
Linux 6.12 – 6.6.67
TIMELINE
Dec 27 Reserved by Linux
Dec 27 Published (CNA: Linux)
Aug 4 RESCORED — CVE-2024-56655 (Linux). CVSS 7.8 → 5.5 (NVD).
Description
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: do not defer rule destruction via call_rcu
nf_tables_chain_destroy can sleep, it can't be used from call_rcu
callbacks.
Moreover, nf_tables_rule_release() is only safe for error unwinding,
while transaction mutex is held and the to-be-desroyed rule was not
exposed to either dataplane or dumps, as it deactives+frees without
the required synchronize_rcu() in-between.
nft_rule_expr_deactivate() callbacks will change ->use counters
of other chains/sets, see e.g. nft_lookup .deactivate callback, these
must be serialized via transaction mutex.
Also add a few lockdep asserts to make this more explicit.
Calling synchronize_rcu() isn't ideal, but fixing this without is hard
and way more intrusive. As-is, we can get:
WARNING: .. net/netfilter/nf_tables_api.c:5515 nft_set_destroy+0x..
Workqueue: events nf_tables_trans_destroy_work
RIP: 0010:nft_set_destroy+0x3fe/0x5c0
Call Trace:
<TASK>
nf_tables_trans_destroy_work+0x6b7/0xad0
process_one_work+0x64a/0xce0
worker_thread+0x613/0x10d0
In case the synchronize_rcu becomes an issue, we can explore alternatives.
One way would be to allocate nft_trans_rule objects + one nft_trans_chain
object, deactivate the rules + the chain and then defer the freeing to the
nft destroy workqueue. We'd still need to keep the synchronize_rcu path as
a fallback to handle -ENOMEM corner cases though.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
| December 27, 2024 | Reserved | Reserved by Linux |
| December 27, 2024 | Published | Published (CNA: Linux) |
| August 4, 2026 | RESCORED | RESCORED — CVE-2024-56655 (Linux). CVSS 7.8 → 5.5 (NVD). |
Affected
Affected products and packages — 2 rows
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
| Linux | Linux | — | 9eee6097ffb26cdd2adb988c0d378fa0d650c737 | — |
| Linux | Linux | — | 6.12 | 6.6.67 |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2024-56655 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.