{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.12.105-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.1.10-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux-6.12"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.12.107-1~deb12u1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  net/sched: act_api: fix TOCTOU NULL deref on a-\u003egoto_chain  tcf_action_exec() handles TC_ACT_GOTO_CHAIN by first checking rcu_access_pointer(a-\u003egoto_chain) and then calling tcf_action_goto_chain_exec(), which does a second, independent rcu_dereference_bh(a-\u003egoto_chain) read and immediately dereferences chain-\u003efilter_chain. A concurrent tcf_action_set_ctrlact() (e.g. the gact replace path) can clear a-\u003egoto_chain between the two reads, so the second read returns NULL and tcf_action_goto_chain_exec() dereferences NULL.  Fix the race by doing a single rcu_dereference_bh() read of a-\u003egoto_chain in tcf_action_exec(), checking it once for NULL, and passing the resulting chain pointer into tcf_action_goto_chain_exec(). This turns the split check/use into a single check/use on one value.",
  "id": "DEBIAN-CVE-2026-74740",
  "modified": "2026-09-19T21:47:29.301341041Z",
  "published": "2026-08-26T15:16:52.743Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-74740"
    }
  ],
  "upstream": [
    "CVE-2026-74740"
  ]
}