FKIE_CVE-2026-64594

Vulnerability from fkie_nvd - Published: 2026-08-06 08:16 - Updated: 2026-08-06 08:16
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_fs: initialize reset_work at allocation time ffs_fs_kill_sb() unconditionally calls cancel_work_sync() on ffs->reset_work when a functionfs instance is unmounted: ffs_data_reset(ffs); cancel_work_sync(&ffs->reset_work); However ffs->reset_work is only ever initialized via INIT_WORK() in ffs_func_set_alt() and ffs_func_disable(), and only on the FFS_DEACTIVATED path. That state is reached solely by ffs_data_closed() when the instance is mounted with the "no_disconnect" option, so for the common case (no "no_disconnect", or mounted and unmounted without ever being deactivated) reset_work is never initialized. ffs_data_new() allocates the ffs_data with kzalloc_obj() and does not initialize reset_work, and ffs_data_reset()/ffs_data_clear() do not touch it either, so reset_work.func is left NULL. cancel_work_sync() on such a work then trips the WARN_ON(!work->func) guard in __flush_work(): WARNING: kernel/workqueue.c:4301 at __flush_work+0x330/0x360, CPU#3: umount Call trace: __flush_work cancel_work_sync ffs_fs_kill_sb [usb_f_fs] deactivate_locked_super deactivate_super cleanup_mnt __cleanup_mnt task_work_run exit_to_user_mode_loop el0_svc On older kernels cancel_work_sync() on a zero-initialized work struct was a silent no-op, which hid the missing initialization. Initialize reset_work once in ffs_data_new() so it is always valid for the lifetime of the ffs_data, and drop the now-redundant INIT_WORK() calls from the two deactivation paths.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0de6ebbabfbbc9c28350283dc97d8a519d5c6dd7
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3137b243c93982fe3460335e12f9247739766e10
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/69faa3779250df14f51d5084f938a99809546e52
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/7fe895e0a9651518c4fc082487da770ff9c14c7f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ba1867999dbc4085e6d8c52ac5266005b8b2bf07
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c36393b0d14e1e9783888f821ffe29381b8f46dc
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/cb19e54ebe9baf3c3243083ade65c937339ccb7b
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d5631081be07f20e764d3cb5c98ac0a1004fba51
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/usb/gadget/function/f_fs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "7fe895e0a9651518c4fc082487da770ff9c14c7f",
              "status": "affected",
              "version": "18d6b32fca3841f7cd9479b4024abd8a9b299281",
              "versionType": "git"
            },
            {
              "lessThan": "0de6ebbabfbbc9c28350283dc97d8a519d5c6dd7",
              "status": "affected",
              "version": "18d6b32fca3841f7cd9479b4024abd8a9b299281",
              "versionType": "git"
            },
            {
              "lessThan": "cb19e54ebe9baf3c3243083ade65c937339ccb7b",
              "status": "affected",
              "version": "18d6b32fca3841f7cd9479b4024abd8a9b299281",
              "versionType": "git"
            },
            {
              "lessThan": "d5631081be07f20e764d3cb5c98ac0a1004fba51",
              "status": "affected",
              "version": "18d6b32fca3841f7cd9479b4024abd8a9b299281",
              "versionType": "git"
            },
            {
              "lessThan": "c36393b0d14e1e9783888f821ffe29381b8f46dc",
              "status": "affected",
              "version": "18d6b32fca3841f7cd9479b4024abd8a9b299281",
              "versionType": "git"
            },
            {
              "lessThan": "69faa3779250df14f51d5084f938a99809546e52",
              "status": "affected",
              "version": "18d6b32fca3841f7cd9479b4024abd8a9b299281",
              "versionType": "git"
            },
            {
              "lessThan": "ba1867999dbc4085e6d8c52ac5266005b8b2bf07",
              "status": "affected",
              "version": "18d6b32fca3841f7cd9479b4024abd8a9b299281",
              "versionType": "git"
            },
            {
              "lessThan": "3137b243c93982fe3460335e12f9247739766e10",
              "status": "affected",
              "version": "18d6b32fca3841f7cd9479b4024abd8a9b299281",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/usb/gadget/function/f_fs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.0"
            },
            {
              "lessThan": "4.0",
              "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": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc3",
              "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\nusb: gadget: f_fs: initialize reset_work at allocation time\n\nffs_fs_kill_sb() unconditionally calls cancel_work_sync() on\nffs-\u003ereset_work when a functionfs instance is unmounted:\n\n\tffs_data_reset(ffs);\n\tcancel_work_sync(\u0026ffs-\u003ereset_work);\n\nHowever ffs-\u003ereset_work is only ever initialized via INIT_WORK() in\nffs_func_set_alt() and ffs_func_disable(), and only on the\nFFS_DEACTIVATED path. That state is reached solely by ffs_data_closed()\nwhen the instance is mounted with the \"no_disconnect\" option, so for the\ncommon case (no \"no_disconnect\", or mounted and unmounted without ever\nbeing deactivated) reset_work is never initialized.\n\nffs_data_new() allocates the ffs_data with kzalloc_obj() and does not\ninitialize reset_work, and ffs_data_reset()/ffs_data_clear() do not touch\nit either, so reset_work.func is left NULL. cancel_work_sync() on such a\nwork then trips the WARN_ON(!work-\u003efunc) guard in __flush_work():\n\n  WARNING: kernel/workqueue.c:4301 at __flush_work+0x330/0x360, CPU#3: umount\n  Call trace:\n   __flush_work\n   cancel_work_sync\n   ffs_fs_kill_sb [usb_f_fs]\n   deactivate_locked_super\n   deactivate_super\n   cleanup_mnt\n   __cleanup_mnt\n   task_work_run\n   exit_to_user_mode_loop\n   el0_svc\n\nOn older kernels cancel_work_sync() on a zero-initialized work struct was\na silent no-op, which hid the missing initialization.\n\nInitialize reset_work once in ffs_data_new() so it is always valid for\nthe lifetime of the ffs_data, and drop the now-redundant INIT_WORK()\ncalls from the two deactivation paths."
    }
  ],
  "id": "CVE-2026-64594",
  "lastModified": "2026-08-06T08:16:34.933",
  "metrics": {},
  "published": "2026-08-06T08:16:34.933",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0de6ebbabfbbc9c28350283dc97d8a519d5c6dd7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3137b243c93982fe3460335e12f9247739766e10"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/69faa3779250df14f51d5084f938a99809546e52"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7fe895e0a9651518c4fc082487da770ff9c14c7f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ba1867999dbc4085e6d8c52ac5266005b8b2bf07"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c36393b0d14e1e9783888f821ffe29381b8f46dc"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/cb19e54ebe9baf3c3243083ade65c937339ccb7b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d5631081be07f20e764d3cb5c98ac0a1004fba51"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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