rcutorture: Fix rcutorture_one_extend_check() splat in RT kernels

{
  "id": "f457af897bbf6b50bf53a0e6ac06670cb713a036602c98e687b405bec568b6cb",
  "url": "https://osv.dev/vulnerability/CVE-2025-39745",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "rcutorture: Fix rcutorture_one_extend_check() splat in RT kernels",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: rcutorture: Fix rcutorture_one_extend_check() splat in RT kernels For built with CONFIG_PREEMPT_RT=y kernels, running rcutorture tests resulted in the following splat: [ 68.797425] rcutorture_one_extend_check during change: Current 0x1 To add 0x1 To remove 0x0 preempt_count() 0x0 [ 68.797533] WARNING: CPU: 2 PID: 512 at kernel/rcu/rcutorture.c:1993 rcutorture_one_extend_check+0x419/0x560 [rcutorture] [ 68.797601] Call Trace: [ 68.797602] [ 68.797619] ? lockdep_softirqs_off+0xa5/0x160 [ 68.797631] rcutorture_one_extend+0x18e/0xcc0 [rcutorture 2466dbd2ff34dbaa36049cb323a80c3306ac997c] [ 68.797646] ? local_clock+0x19/0x40 [ 68.797659] rcu_torture_one_read+0xf0/0x280 [rcutorture 2466dbd2ff34dbaa36049cb323a80c3306ac997c] [ 68.797678] ? __pfx_rcu_torture_one_read+0x10/0x10 [rcutorture 2466dbd2ff34dbaa36049cb323a80c3306ac997c] [ 68.797804] ? __pfx_rcu_torture_timer+0x10/0x10 [rcutorture 2466dbd2ff34dbaa36049cb323a80c3306ac997c] [ 68.797815] rcu-torture: rcu_torture_reader task started [ 68.797824] rcu-torture: Creating rcu_torture_reader task [ 68.797824] rcu_torture_reader+0x238/0x580 [rcutorture 2466dbd2ff34dbaa36049cb323a80c3306ac997c] [ 68.797836] ? kvm_sched_clock_read+0x15/0x30 Disable BH does not change the SOFTIRQ corresponding bits in preempt_count() for RT kernels, this commit therefore use softirq_count() to check the if BH is disabled.",
    "evidence": "osv:CVE-2025-39745",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.15.11",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.16.2",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2025-39745",
      "aliases": [
        "CVE-2025-39745"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "ec9d6356bfda69abe5f4767dd56c964127913233"
                },
                {
                  "fixed": "a85550267247cdf5e7499be00ea8e388ab014e50"
                },
                {
                  "fixed": "69c5ae0f441c2d72e8f48dc1e08464c172360c4c"
                },
                {
                  "fixed": "8d71351d88e478d3c4e945e3218e97ec677fd807"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-39745.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.14.0"
                },
                {
                  "fixed": "6.15.11"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.16.0"
                },
                {
                  "fixed": "6.16.2"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-39745.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:48.315825960Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/69c5ae0f441c2d72e8f48dc1e08464c172360c4c",
        "https://git.kernel.org/stable/c/8d71351d88e478d3c4e945e3218e97ec677fd807",
        "https://git.kernel.org/stable/c/a85550267247cdf5e7499be00ea8e388ab014e50",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39745.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-39745",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39745.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-39745",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 516682,
  "published_at": "2025-09-11T16:52:18.423+00:00"
}