CVE-2026-98851
Our Analysis: Environment Specific
Our model has classified this vulnerability as relevant to Environment Specific Systems, helping your team prioritize efforts effectively.
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.