{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2025-39978",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2025-39978"
  ],
  "published": "2025-10-15T07:57:23Z",
  "summary": "octeontx2-pf: Fix potential use after free in otx2_tc_add_flow()",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nocteontx2-pf: Fix potential use after free in otx2_tc_add_flow()\n\nThis code calls kfree_rcu(new_node, rcu) and then dereferences \"new_node\"\nand then dereferences it on the next line.  Two lines later, we take\na mutex so I don't think this is an RCU safe region.  Re-order it to do\nthe dereferences before queuing up the free.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.155",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-39978"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/5723120423a753a220b8b2954b273838b9d7e74a"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/df2c071061ed52d2225d97b212d27ecedf456b8a"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/c41b2941a024d4ec7c768e16ffb10a74b188fced"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/a8a63f27c3a8a3714210d32b12fd0f16d0337414"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d9c70e93ec5988ab07ad2a92d9f9d12867f02c56"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T12:19:11Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The vulnerable path is reached only through a local `RTM_NEWTFILTER` netlink message installing a tc flower filter with a police action on an octeontx2 PF/VF/representor netdev. There is no remote packet-processing path into `otx2_tc_add_flow()`.\nAC:L - The attacker deterministically forces the `free_leaf:` error path by installing police-action flower rules until MCAM/mbox resources are exhausted, and widens the RCU grace-period window at will by contending `nic->mbox.lock` from a second thread so `mutex_lock()` sleeps. Both the free and the reclaim/spray side are under attacker control.\nPR:L - Only CAP_NET_ADMIN over the netns owning the device is needed, and `otx2_setup_tc` is shared by the VF (`otx2_vf.c:535`) and representor (`rep.c:495`) drivers, whose netdevs are commonly delegated into container netns owned by unprivileged user namespaces where container-root holds CAP_NET_ADMIN with no init-namespace privilege.\nUI:N - The entire sequence is driven by the attacker's own netlink filter-install requests. No victim action or cooperation is involved.\nS:U - The use-after-free corrupts kernel heap and driver state within the same kernel security authority. No VM, IOMMU, or sandbox boundary is crossed.\nC:H - The freed `struct otx2_tc_flow` is read back after reclaim, giving a read primitive over whatever slab object replaced it, and the stale `rq`/`leaf_profile` values are further exposed to userspace through `netdev_err()` kernel-log messages.\nI:H - `__clear_bit(new_node->rq, &nic->rq_bmap)` uses a UAF-derived u16 index against a single `unsigned long`, yielding an out-of-bounds bit clear up to ~8 KB into and past `struct otx2_nic` (mbox state, queue and function pointers), and the stale `leaf_profile` makes firmware tear down another flow's hardware policer, silently defeating QoS/rate-limit enforcement.\nA:H - A use-after-free on a slab object combined with an out-of-bounds bit clear into the driver's private structure reliably oopses the kernel or wedges the NIC's mailbox/queue state, and the attacker can repeat it at will."
    }
  }
}