{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2024-56655",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2024-56655"
  ],
  "published": "2024-12-27T15:08:24Z",
  "summary": "netfilter: nf_tables: do not defer rule destruction via call_rcu",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_tables: do not defer rule destruction via call_rcu\n\nnf_tables_chain_destroy can sleep, it can't be used from call_rcu\ncallbacks.\n\nMoreover, nf_tables_rule_release() is only safe for error unwinding,\nwhile transaction mutex is held and the to-be-desroyed rule was not\nexposed to either dataplane or dumps, as it deactives+frees without\nthe required synchronize_rcu() in-between.\n\nnft_rule_expr_deactivate() callbacks will change ->use counters\nof other chains/sets, see e.g. nft_lookup .deactivate callback, these\nmust be serialized via transaction mutex.\n\nAlso add a few lockdep asserts to make this more explicit.\n\nCalling synchronize_rcu() isn't ideal, but fixing this without is hard\nand way more intrusive.  As-is, we can get:\n\nWARNING: .. net/netfilter/nf_tables_api.c:5515 nft_set_destroy+0x..\nWorkqueue: events nf_tables_trans_destroy_work\nRIP: 0010:nft_set_destroy+0x3fe/0x5c0\nCall Trace:\n <TASK>\n nf_tables_trans_destroy_work+0x6b7/0xad0\n process_one_work+0x64a/0xce0\n worker_thread+0x613/0x10d0\n\nIn case the synchronize_rcu becomes an issue, we can explore alternatives.\n\nOne way would be to allocate nft_trans_rule objects + one nft_trans_chain\nobject, deactivate the rules + the chain and then defer the freeing to the\nnft destroy workqueue.  We'd still need to keep the synchronize_rcu path as\na fallback to handle -ENOMEM corner cases though.",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.6.62-1+rpt1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.6.62+rpt-rpi-2712",
            "binary_version": "1:6.6.62-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.62+rpt-rpi-v6",
            "binary_version": "1:6.6.62-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.62+rpt-rpi-v7",
            "binary_version": "1:6.6.62-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.62+rpt-rpi-v7l",
            "binary_version": "1:6.6.62-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.6.62+rpt-rpi-v8",
            "binary_version": "1:6.6.62-1+rpt1"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.6.62-1+rpt1": {
            "linux_commit": "dd2394360860d15146c96635796a75b05bb32b61",
            "upstream_version": "6.6.62",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.6.67"
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2024-56655"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/5146c27b2780aac59876a887a5f4e793b8949862"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/2991dc357a28b61c13ed1f7b59e9251e2b4562fb"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/b8d8f53e1858178882b881b8c09f94ef0e83bf76"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/b0f013bebf94fe7ae75e5a53be2f2bd1cc1841e3"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/27f0574253f6c24c8ee4e3f0a685b75ed3a256ed"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/7cf0bd232b565d9852cb25fd094f77254773e048"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/b04df3da1b5c6f6dc7cdccc37941740c078c4043"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T11:52:36Z"
  }
}