{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-53175",
  "modified": "2026-10-07T14:35:31Z",
  "upstream": [
    "CVE-2026-53175"
  ],
  "published": "2026-06-25T08:41:40Z",
  "summary": "inet: frags: fix use-after-free caused by the fqdir_pre_exit() flush",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ninet: frags: fix use-after-free caused by the fqdir_pre_exit() flush\n\nOn netns teardown, fqdir_pre_exit() walks the fqdir rhashtable and\nflushes every fragment queue that is not yet complete using\ninet_frag_queue_flush(). That helper frees all the skbs queued on the\nfragment queue but does not set INET_FRAG_COMPLETE, and leaves\nq->fragments_tail and q->last_run_head pointing at the freed skbs.\nThe queue itself stays in the rhashtable.\n\nfqdir_pre_exit() first lowers high_thresh to 0 to stop new queue lookups,\nbut it cannot stop a fragment that already obtained the queue through\ninet_frag_find() earlier and stalled just before taking the queue lock.\nOnce that fragment resumes after the flush and takes the queue lock,\nit passes the INET_FRAG_COMPLETE check and then dereferences the freed\nfragments_tail. inet_frag_queue_insert() reads FRAG_CB() and ->len of\nthat pointer and, on the append path, writes ->next_frag, causing a\nslab use-after-free. IPv6, nf_conntrack_reasm6 and 6lowpan reassembly\nshare the same flush path and are affected as well.\n\nReset rb_fragments, fragments_tail and last_run_head in\ninet_frag_queue_flush() so a flushed queue no longer points at the\nfreed skbs. A fragment that resumes after the flush and takes the\nqueue lock then finds an empty queue and starts a new run instead of\ndereferencing the freed fragments_tail. ip_frag_reinit() already\nperformed this reset after its own flush, so drop the now duplicate\ncode there.",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.12.93-1+rpt1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.12.93+rpt-rpi-2712",
            "binary_version": "1:6.12.93-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.12.93+rpt-rpi-v6",
            "binary_version": "1:6.12.93-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.12.93+rpt-rpi-v7",
            "binary_version": "1:6.12.93-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.12.93+rpt-rpi-v7l",
            "binary_version": "1:6.12.93-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.12.93+rpt-rpi-v8",
            "binary_version": "1:6.12.93-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.12.93+rpt-rpi-v8-rt",
            "binary_version": "1:6.12.93-1+rpt1"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.12.93-1+rpt1": {
            "linux_commit": "d8ab4e908235da7727f22dd36ad5af224671677d",
            "upstream_version": "6.12.93",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.12.94"
          }
        }
      }
    },
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:13",
        "name": "linux"
      },
      "versions": [
        "1:6.18.29-1+rpt1",
        "1:6.18.33-1+rpt1",
        "1:6.18.34-1+rpt1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.18.29+rpt-rpi-2712",
            "binary_version": "1:6.18.29-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.29+rpt-rpi-v6",
            "binary_version": "1:6.18.29-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.29+rpt-rpi-v7",
            "binary_version": "1:6.18.29-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.29+rpt-rpi-v8",
            "binary_version": "1:6.18.29-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.29+rpt-rpi-v8-rt",
            "binary_version": "1:6.18.29-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.33+rpt-rpi-2712",
            "binary_version": "1:6.18.33-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.33+rpt-rpi-v6",
            "binary_version": "1:6.18.33-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.33+rpt-rpi-v7",
            "binary_version": "1:6.18.33-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.33+rpt-rpi-v8",
            "binary_version": "1:6.18.33-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.33+rpt-rpi-v8-rt",
            "binary_version": "1:6.18.33-1+rpt1"
          },
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            "binary_version": "1:6.18.34-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.34+rpt-rpi-v6",
            "binary_version": "1:6.18.34-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.34+rpt-rpi-v7",
            "binary_version": "1:6.18.34-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.34+rpt-rpi-v8",
            "binary_version": "1:6.18.34-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.18.34+rpt-rpi-v8-rt",
            "binary_version": "1:6.18.34-1+rpt1"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.18.29-1+rpt1": {
            "linux_commit": "66318c5b5cd8145a662303af12ed39ac07eb27cc",
            "upstream_version": "6.18.29",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.18.36"
          },
          "1:6.18.33-1+rpt1": {
            "linux_commit": "95b85bebbedcaedfa7ca79116ed38b7376fba412",
            "upstream_version": "6.18.33",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.18.36"
          },
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            "linux_commit": "c8c7494100e99ee05b11aaa4f0588a223a63d1af",
            "upstream_version": "6.18.34",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.18.36"
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-53175"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/0e823ca0e7391630784ae7dd0981b7ad170a93d9"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/c22599cc90e1cd5f8129c8670bd68a02ff7177b4"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/89b909e9704587bfecc1aab1d37e98faee03b9f9"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/010c3313a4d178dc2d3ce958d2e5cb055e2864c1"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/32594b09854970d7ba83eb2dc8c69a2edd158c8e"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T13:16:28Z"
  }
}