FKIE_CVE-2026-72491

Vulnerability from fkie_nvd - Published: 2026-08-15 06:22 - Updated: 2026-08-17 06:19
Severity
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: net/9p: fix race condition on rdma->state in trans_rdma.c The rdma->state field is modified without holding req_lock in both recv_done() and p9_cm_event_handler(), while rdma_request() accesses the same field under the req_lock spinlock. This inconsistent locking creates a race condition: - recv_done() running in softirq completion context sets rdma->state = P9_RDMA_FLUSHING without acquiring req_lock - p9_cm_event_handler() modifies rdma->state at multiple points (ADDR_RESOLVED, ROUTE_RESOLVED, ESTABLISHED, CLOSED) without req_lock - rdma_request() uses spin_lock_irqsave(&rdma->req_lock, flags) to protect the read-modify-write of rdma->state The race can cause lost state transitions: recv_done() or the CM event handler could set state to FLUSHING/CLOSED while rdma_request() is concurrently checking or modifying state under the lock, leading to the FLUSHING transition being silently overwritten by CLOSING. This corrupts the connection state machine and can cause use-after-free on RDMA request objects during teardown. Fix by adding req_lock protection to all rdma->state modifications in recv_done() and p9_cm_event_handler(), matching the pattern already used in rdma_request(). Use spin_lock_irqsave/spin_unlock_irqrestore in the CM event handler since it can race with recv_done() which runs in softirq context. Tested with a kernel module that races two threads (simulating rdma_request and recv_done/CM handler) on rdma->state with proper locking: 5.5M+ FLUSHING writes over 27M iterations with 0 lost transitions.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/13bf9879b778b2f4b260b45bed18f31806120d1e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/151f8cf5b23d8a534d884432a82a6d54d5a61989
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3970a19a80de530b801b6256354d4a529a9a2d6c
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4cee2b8766045059d5e0b8114837b4a8efe827ac
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5424138848eb7d7d8a7196676e90a2cbf2142454
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/7d54894a1ee265a72d70f7cae1da6cc774cccc71
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/8aadc136d8e8d8fc95d7982d213cfe2234dfcf2b
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ebbcbe5c0db215feecc17def06178da443f4eea6
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/9p/trans_rdma.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "4cee2b8766045059d5e0b8114837b4a8efe827ac",
              "status": "affected",
              "version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b",
              "versionType": "git"
            },
            {
              "lessThan": "5424138848eb7d7d8a7196676e90a2cbf2142454",
              "status": "affected",
              "version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b",
              "versionType": "git"
            },
            {
              "lessThan": "3970a19a80de530b801b6256354d4a529a9a2d6c",
              "status": "affected",
              "version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b",
              "versionType": "git"
            },
            {
              "lessThan": "8aadc136d8e8d8fc95d7982d213cfe2234dfcf2b",
              "status": "affected",
              "version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b",
              "versionType": "git"
            },
            {
              "lessThan": "151f8cf5b23d8a534d884432a82a6d54d5a61989",
              "status": "affected",
              "version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b",
              "versionType": "git"
            },
            {
              "lessThan": "13bf9879b778b2f4b260b45bed18f31806120d1e",
              "status": "affected",
              "version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b",
              "versionType": "git"
            },
            {
              "lessThan": "ebbcbe5c0db215feecc17def06178da443f4eea6",
              "status": "affected",
              "version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b",
              "versionType": "git"
            },
            {
              "lessThan": "7d54894a1ee265a72d70f7cae1da6cc774cccc71",
              "status": "affected",
              "version": "473c7dd1d7b59ff8f88a5154737e3eac78a96e5b",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "3479b3c35e82ed10aa0ca2ee9e78c4eded06ba62",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "c01ddaa54d7411e964ffd250c018d8469c5852f2",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "9e69c673fe077b8dc491cd8406c9bdcb1f76dee2",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "e48e7e27e4dfd00c81e0381e7cee610cce021452",
              "versionType": "git"
            },
            {
              "lessThan": "4.5",
              "status": "affected",
              "version": "4.4.185",
              "versionType": "semver"
            },
            {
              "lessThan": "4.10",
              "status": "affected",
              "version": "4.9.185",
              "versionType": "semver"
            },
            {
              "lessThan": "4.15",
              "status": "affected",
              "version": "4.14.132",
              "versionType": "semver"
            },
            {
              "lessThan": "4.20",
              "status": "affected",
              "version": "4.19.57",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/9p/trans_rdma.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.20"
            },
            {
              "lessThan": "4.20",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.261",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.212",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/9p: fix race condition on rdma-\u003estate in trans_rdma.c\n\nThe rdma-\u003estate field is modified without holding req_lock in both\nrecv_done() and p9_cm_event_handler(), while rdma_request() accesses\nthe same field under the req_lock spinlock. This inconsistent locking\ncreates a race condition:\n\n- recv_done() running in softirq completion context sets\n  rdma-\u003estate = P9_RDMA_FLUSHING without acquiring req_lock\n\n- p9_cm_event_handler() modifies rdma-\u003estate at multiple points\n  (ADDR_RESOLVED, ROUTE_RESOLVED, ESTABLISHED, CLOSED) without\n  req_lock\n\n- rdma_request() uses spin_lock_irqsave(\u0026rdma-\u003ereq_lock, flags) to\n  protect the read-modify-write of rdma-\u003estate\n\nThe race can cause lost state transitions: recv_done() or the CM\nevent handler could set state to FLUSHING/CLOSED while rdma_request()\nis concurrently checking or modifying state under the lock, leading to\nthe FLUSHING transition being silently overwritten by CLOSING. This\ncorrupts the connection state machine and can cause use-after-free on\nRDMA request objects during teardown.\n\nFix by adding req_lock protection to all rdma-\u003estate modifications in\nrecv_done() and p9_cm_event_handler(), matching the pattern already\nused in rdma_request(). Use spin_lock_irqsave/spin_unlock_irqrestore\nin the CM event handler since it can race with recv_done() which runs\nin softirq context.\n\nTested with a kernel module that races two threads (simulating\nrdma_request and recv_done/CM handler) on rdma-\u003estate with proper\nlocking: 5.5M+ FLUSHING writes over 27M iterations with 0 lost\ntransitions."
    }
  ],
  "id": "CVE-2026-72491",
  "lastModified": "2026-08-17T06:19:17.397",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-15T06:22:23.400",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/13bf9879b778b2f4b260b45bed18f31806120d1e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/151f8cf5b23d8a534d884432a82a6d54d5a61989"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3970a19a80de530b801b6256354d4a529a9a2d6c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4cee2b8766045059d5e0b8114837b4a8efe827ac"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5424138848eb7d7d8a7196676e90a2cbf2142454"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7d54894a1ee265a72d70f7cae1da6cc774cccc71"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/8aadc136d8e8d8fc95d7982d213cfe2234dfcf2b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ebbcbe5c0db215feecc17def06178da443f4eea6"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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