Description
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nft_flow_offload: drop flowtable reference on init error path
nft_flow_offload_init() bumps the flowtable use count with
nft_use_inc() before calling nf_ct_netns_get(). When the latter
fails, the error is returned as-is and the reference is leaked.
The upper layers do not balance it either: nf_tables_newexpr()
clears expr->ops when the expression init callback fails, so the
nft_expr_more() iteration in nft_rule_expr_deactivate() and
nf_tables_rule_destroy() stops right before the failed expression
and its ->destroy callback, which would drop the reference, never
runs.
Each failed rule addition therefore leaks one flowtable reference
and the flowtable can no longer be removed: NFT_MSG_DELFLOWTABLE
keeps reporting -EBUSY even though no rule references it.
Save the nf_ct_netns_get() return value and undo the nft_use_inc()
when it fails, restoring the inc/dec pairing within
nft_flow_offload_init() itself.
netfilter: nft_flow_offload: drop flowtable reference on init error path
nft_flow_offload_init() bumps the flowtable use count with
nft_use_inc() before calling nf_ct_netns_get(). When the latter
fails, the error is returned as-is and the reference is leaked.
The upper layers do not balance it either: nf_tables_newexpr()
clears expr->ops when the expression init callback fails, so the
nft_expr_more() iteration in nft_rule_expr_deactivate() and
nf_tables_rule_destroy() stops right before the failed expression
and its ->destroy callback, which would drop the reference, never
runs.
Each failed rule addition therefore leaks one flowtable reference
and the flowtable can no longer be removed: NFT_MSG_DELFLOWTABLE
keeps reporting -EBUSY even though no rule references it.
Save the nf_ct_netns_get() return value and undo the nft_use_inc()
when it fails, restoring the inc/dec pairing within
nft_flow_offload_init() itself.
Published:
2026-10-18
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
Analysis
No analysis available yet.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
|||||||||||||||||||||
| Linux | Linux | affected |
|
No data.
No data.
No data available yet.
Remediation
No remediation available yet.
Tracking
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Advisories
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References
History
Sun, 18 Oct 2026 16:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_flow_offload: drop flowtable reference on init error path nft_flow_offload_init() bumps the flowtable use count with nft_use_inc() before calling nf_ct_netns_get(). When the latter fails, the error is returned as-is and the reference is leaked. The upper layers do not balance it either: nf_tables_newexpr() clears expr->ops when the expression init callback fails, so the nft_expr_more() iteration in nft_rule_expr_deactivate() and nf_tables_rule_destroy() stops right before the failed expression and its ->destroy callback, which would drop the reference, never runs. Each failed rule addition therefore leaks one flowtable reference and the flowtable can no longer be removed: NFT_MSG_DELFLOWTABLE keeps reporting -EBUSY even though no rule references it. Save the nf_ct_netns_get() return value and undo the nft_use_inc() when it fails, restoring the inc/dec pairing within nft_flow_offload_init() itself. | |
| Title | netfilter: nft_flow_offload: drop flowtable reference on init error path | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-10-18T15:50:50.910Z
Reserved: 2026-09-25T10:25:14.376Z
Link: CVE-2026-98851
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-10-18T16:17:39.490
Modified: 2026-10-18T16:17:39.490
Link: CVE-2026-98851
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.