{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-80982",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-80982"
  ],
  "published": "2026-09-11T19:47:07Z",
  "summary": "net/smc: fix use-after-free in smc_rx_pipe_buf_release()",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: fix use-after-free in smc_rx_pipe_buf_release()\n\nsmc_rx_splice() hands RMB pages to a pipe and takes a socket reference\nper entry so the smc_sock stays alive until the reader finishes. The\nconnection does not: a concurrent close runs smc_conn_free(), which\nreleases the receive buffer back to the link group pool.\n\nsmc_rx_pipe_buf_release() tests sk_state before taking the socket lock.\nThe state can change between the test and the lock, and\nsmc_rx_update_cons() then dereferences conn->rmb_desc and walks\nconn->lgr, which smc_conn_free() has already released. On the\nis_reg_err path smcr_buf_unuse() frees the descriptor outright, so\nthis is a use-after-free.\n\nTake the socket lock first and test conn->freed instead.\nsmc_conn_free() sets that flag before releasing anything, and every\ncaller holds the socket lock. The two paths exclude each other: either\nthe pipe release runs first with everything valid, or it sees the flag\nand skips the update.",
  "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": "6.1.188",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-80982"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/dadd97c8296b23aa816e91ed70041820ae087baa"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/df441f3efbb50eb0f120b8de4bf441c31fb0551d"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/6a644a7340df978785f3109d1e0726a982ce2c6f"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/0761e49aa78c2f1362511054c6e9670653858837"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/0926f59ca0f94120895b92180c636a48d0ed3a6d"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/c924884743e948e25625b7fbf3ee2a9325a204a7"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-09-14T12:06:03Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The UAF is in smc_rx_pipe_buf_release(), a pipe_buf_ops.release callback reached only via local splice() on an AF_SMC socket (syscall -> sock_splice_read -> smc_splice_read -> smc_rx_recvmsg -> smc_rx_splice). A remote SMC peer can supply RMB data or close the connection, but cannot invoke the splice pipe-buffer release path by itself.\nAC:L - The attacker controls both sides of the TOCTOU: one thread splices SMC Rx data into a pipe and then reads or closes it (unlocked sk_state check, then lock_sock), while another closes the socket so smc_conn_free() drops rmb_desc/lgr in that window. The race is fully attacker-driven and retryable.\nPR:L - socket(AF_SMC) or IPPROTO_SMC, connect/listen (loopback-ism, ISM, or RoCE), splice(2), and close(2) have no capability checks and are available to an unprivileged local user. User-namespace admin rights are not required.\nUI:N - A single unprivileged process can act as both SMC endpoints on loopback or a local fabric, splice received data into a pipe, and race close() against pipe-buffer release. No victim user action is required.\nS:U - The corruption is confined to kernel objects (smc_buf_desc, smc_link_group) in the same kernel security authority. This is standard kernel memory corruption, not a VM, IOMMU, or sandbox boundary escape.\nC:H - smc_rx_update_cons() dereferences conn->rmb_desc and walks conn->lgr after smc_conn_free()/smcr_buf_unuse() released them; on the is_reg_err path smc_buf_free() frees the descriptor outright. Per kernel CVSS guidance, this UAF of heap objects enables arbitrary kernel-memory disclosure.\nI:H - The same UAF writes consumer cursors and may call smc_tx_consumer_update() -> smc_cdc_get_slot_and_msg_send() or queue_delayed_work on conn->lgr->tx_wq after the link group is freed, enabling heap reuse, arbitrary write, and control-flow hijack.\nA:H - Dereferencing the freed rmb_desc or link group produces a kernel oops or panic. Use-after-free on this path crashes the host even when not fully exploited, and the attacker can repeat the race at will."
    }
  }
}