media: b2c2: Fix use-after-free causing by irq_check_work in flexcop_pci_remove

{
  "id": "72dee9dac4723a425b516b654e4d5eb01b2b7f94e3208284495bc21be6f7ecd0",
  "url": "https://osv.dev/vulnerability/CVE-2025-39996",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "media: b2c2: Fix use-after-free causing by irq_check_work in flexcop_pci_remove",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: media: b2c2: Fix use-after-free causing by irq_check_work in flexcop_pci_remove The original code uses cancel_delayed_work() in flexcop_pci_remove(), which does not guarantee that the delayed work item irq_check_work has fully completed if it was already running. This leads to use-after-free scenarios where flexcop_pci_remove() may free the flexcop_device while irq_check_work is still active and attempts to dereference the device. A typical race condition is illustrated below: CPU 0 (remove) | CPU 1 (delayed work callback) flexcop_pci_remove() | flexcop_pci_irq_check_work() cancel_delayed_work() | flexcop_device_kfree(fc_pci->fc_dev) | | fc = fc_pci->fc_dev; // UAF This is confirmed by a KASAN report: ================================================================== BUG: KASAN: slab-use-after-free in __run_timer_base.part.0+0x7d7/0x8c0 Write of size 8 at addr ffff8880093aa8c8 by task bash/135 ... Call Trace: dump_stack_lvl+0x55/0x70 print_report+0xcf/0x610 ? __run_timer_base.part.0+0x7d7/0x8c0 kasan_report+0xb8/0xf0 ? __run_timer_base.part.0+0x7d7/0x8c0 __run_timer_base.part.0+0x7d7/0x8c0 ? __pfx___run_timer_base.part.0+0x10/0x10 ? __pfx_read_tsc+0x10/0x10 ? ktime_get+0x60/0x140 ? lapic_next_event+0x11/0x20 ? clockevents_program_event+0x1d4/0x2a0 run_timer_softirq+0xd1/0x190 handle_softirqs+0x16a/0x550 irq_exit_rcu+0xaf/0xe0 sysvec_apic_timer_interrupt+0x70/0x80 ... Allocated by task 1: kasan_save_stack+0x24",
    "evidence": "osv:CVE-2025-39996",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
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        "prerequisites": [],
        "fixed_versions": [
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        "affected_versions": []
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    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2025-39996",
      "aliases": [
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      "modified": "2026-10-28T02:30:42.451082874Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/01e03fb7db419d39e18d6090d4873c1bff103914",
        "https://git.kernel.org/stable/c/120e221b4bbe9d0f6c09b5c4dc53ca4ad91d956b",
        "https://git.kernel.org/stable/c/3ffabc79388e68877d9c02f724a0b7a38d519daf",
        "https://git.kernel.org/stable/c/514a519baa9e2be7ddc2714bd730bc5a883e1244",
        "https://git.kernel.org/stable/c/607010d07b8a509b01ed15ea12744acac6536a98",
        "https://git.kernel.org/stable/c/6a92f5796880f5aa345f0fed53ef511e3fd6f706",
        "https://git.kernel.org/stable/c/bb10a9ddc8d6c5dbf098f21eb1055a652652e524",
        "https://git.kernel.org/stable/c/bde8173def374230226e8554efb51b271f4066ec",
        "https://git.kernel.org/stable/c/d502df8a716d993fa0f9d8c00684f1190750e28e",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39996.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-39996",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
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    "security_relevant": true,
    "severity_evidence": null
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  "source_id": "core-osv",
  "document_id": 510193,
  "published_at": "2025-10-15T07:58:21.049+00:00"
}