{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2024-38544",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2024-38544"
  ],
  "published": "2024-06-19T13:36:08Z",
  "summary": "RDMA/rxe: Fix seg fault in rxe_comp_queue_pkt",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/rxe: Fix seg fault in rxe_comp_queue_pkt\n\nIn rxe_comp_queue_pkt() an incoming response packet skb is enqueued to the\nresp_pkts queue and then a decision is made whether to run the completer\ntask inline or schedule it. Finally the skb is dereferenced to bump a 'hw'\nperformance counter. This is wrong because if the completer task is\nalready running in a separate thread it may have already processed the skb\nand freed it which can cause a seg fault.  This has been observed\ninfrequently in testing at high scale.\n\nThis patch fixes this by changing the order of enqueuing the packet until\nafter the counter is accessed.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/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": "6.1.93",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2024-38544"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/c91fb72a2ca6480d8d77262eef52dc5b178463a3"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/de5a059e36657442b5637cc16df5163e435b9cb4"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e0e14dd35d4242340c7346aac60c7ff8fbf87ffc"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/faa8d0ecf6c9c7c2ace3ca3e552180ada6f75e19"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/21b4c6d4d89030fd4657a8e7c8110fd941049794"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/bbad88f111a1829f366c189aa48e7e58e57553fc"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/30df4bef8b8e183333e9b6e9d4509d552c7da6eb"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/2b23b6097303ed0ba5f4bc036a1c07b6027af5c6"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T11:52:36Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 9.8,
      "cvss_v3_severity": "Critical",
      "scenario": "AV:N - The vulnerable function is reached directly from the Soft-RoCE UDP encapsulation receive handler on port 4791 (rxe_udp_encap_recv \u2192 rxe_rcv \u2192 rxe_rcv_pkt \u2192 rxe_comp_queue_pkt), processing data from a remote peer. RoCEv2 is routable IP/UDP traffic, so the attacker is not confined to the local L2 segment.\nAC:L - The attacker controls both sides of the race: the vulnerable counter access only occurs when resp_pkts already holds another packet (queue_len > 1), a condition created by bursting response packets while the completer work item concurrently drains and kfree_skb()s them on another CPU. The commit describes it triggering under high packet load, which is exactly what an attacker-driven flood produces.\nPR:N - RoCEv2 provides no authentication; the only checks before the UAF are QPN lookup, QP state, source/destination IP matching the QP's address vector, default pkey, and a plain CRC32 ICRC that any attacker can compute. A malicious or compromised RDMA peer, or an attacker spoofing the peer's source address, needs no credentials on the target system.\nUI:N - Exploitation requires only that the target have an active RC/UC queue pair in RTS state, which is the normal steady-state operating condition of an RDMA connection. No action by any local user or administrator is needed at attack time.\nS:U - The use-after-free corrupts kernel slab memory and is exploited within the kernel's own security authority. No VM, IOMMU, or sandbox boundary is crossed.\nC:H - The freed skb's control block is read after kfree_skb(), so the attacker can groom the reallocated slab object to source the rxe pointer, and a use-after-free on the skb slab is a classic primitive for leaking adjacent kernel memory and defeating KASLR.\nI:H - The stale pointer read from the freed object is immediately passed to rxe_counter_inc(), which performs atomic64_inc(&rxe->stats_counters[index]) \u2014 a write through an attacker-influenceable pointer, giving a targeted 64-bit increment primitive that can corrupt arbitrary kernel structures and be escalated to control-flow hijack.\nA:H - The commit explicitly reports a segmentation fault (kernel oops) from this dereference, and any unresolved use-after-free of an skb reliably crashes or panics the kernel, which a remote attacker can trigger repeatedly."
    }
  }
}