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CVE PROGRAM SOURCE RECORDUnscored

CVE-2026-98851

netfilter: nft_flow_offload: drop flowtable reference on init error path

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • a3c90f7a2323b331ae816d5b0633e68148e25d04 to < 4e5a6d89083af6f23f0ac2cb611ef267590a3eceaffected
  • a3c90f7a2323b331ae816d5b0633e68148e25d04 to < 1f43b6b099fa39032780b9494cedfd98f318f3c4affected
  • a3c90f7a2323b331ae816d5b0633e68148e25d04 to < 87f4914758f2da10b56cdb7f90ed815ade1e8ea3affected
  • a3c90f7a2323b331ae816d5b0633e68148e25d04 to < 1d27214fd9a4d2c0c6d998fc9d4fb61448a3438eaffected
  • a3c90f7a2323b331ae816d5b0633e68148e25d04 to < 64ac0cb574c740bf723affb79b646eeba920db6baffected
  • a3c90f7a2323b331ae816d5b0633e68148e25d04 to < c5f91098edee98c015f78488460a0609e62582a5affected
  • a3c90f7a2323b331ae816d5b0633e68148e25d04 to < 4cd378423a33194a773c267fc58606d28fce95cfaffected
  • a3c90f7a2323b331ae816d5b0633e68148e25d04 to < 747928b5d4ff8c8de55138a54c13980e4bb88578affected

Linux Linux

Default version status: affected

  • 4.16affected
  • 0 to < 4.16unaffected
  • 5.10.273 to ≤ 5.10.*unaffected
  • 5.15.224 to ≤ 5.15.*unaffected
  • 6.1.191 to ≤ 6.1.*unaffected
  • 6.6.160 to ≤ 6.6.*unaffected
  • 6.12.113 to ≤ 6.12.*unaffected
  • 6.18.56 to ≤ 6.18.*unaffected
  • 7.2.10 to ≤ 7.2.*unaffected
  • 7.3 to ≤ *unaffected

References