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usb: gadget: f_tcm: keep port count until LUN teardown completes

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_tcm: keep port count until LUN teardown completes tcm_usbg_drop_nexus() permits session removal once tpg_port_count reaches zero. However, usbg_port_unlink() currently decrements that count from the fabric_pre_unlink() callback, before core_dev_del_lun() waits for active se_lun references to drain. If removal of the last LUN races a nexus removal, the latter can observe a zero port count and call target_remove_session(). This frees sess_cmd_map while an in-flight struct usbg_cmd, including its work item, can still be accessed. Overlapping the last-LUN unlink with nexus removal reproduces this lifetime violation as a DEBUG_OBJECTS "free active" warning for usbg_cmd_work, followed by a target-core BUG/Oops. The generic target-core unlink path has no callback after core_dev_del_lun() completes. Add an optional fabric_post_unlink() callback and use it for the f_tcm port count. The count now remains nonzero until core_dev_del_lun() has finished draining active LUN references, preventing nexus removal from freeing the session during command completion.

Announced Source revision 1
Original source ↗

CVE-2026-80854

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-80854

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "c52661d60f636d17e26ad834457db333bd1df494",
        "lessThan": "c494c5562ca69b61a82f566e3b87a445d2c28929",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "c52661d60f636d17e26ad834457db333bd1df494",
        "lessThan": "c1f359d9a5efed458946063de65ddbeaacc4f165",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "c52661d60f636d17e26ad834457db333bd1df494",
        "lessThan": "178f59a0bccd3f66cdfa5184310f31a58b7257c4",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "c52661d60f636d17e26ad834457db333bd1df494",
        "lessThan": "ad6f0375d2e93a1d8c015463e5e92dfcb26e311b",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "c52661d60f636d17e26ad834457db333bd1df494",
        "lessThan": "2efbfd42441d3ef8137aff2d59e9835e1d5ae780",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "c52661d60f636d17e26ad834457db333bd1df494",
        "lessThan": "85aa61fedcb4eb13f3dc5db73f6dc359f41f5d95",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "c52661d60f636d17e26ad834457db333bd1df494",
        "lessThan": "bbd6aa311a9f4dd17822c7557451458d3d2e980b",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "c52661d60f636d17e26ad834457db333bd1df494",
        "lessThan": "eaa96a8458f54d6cf0954242ab8b1df2a6fccafa",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "c52661d60f636d17e26ad834457db333bd1df494",
        "lessThan": "c39d0916da47d94909391876c9e5bd429ea7b1b9",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "drivers/target/target_core_fabric_configfs.c",
      "drivers/usb/gadget/function/f_tcm.c",
      "include/target/target_core_fabric.h"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "3.5"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "3.5",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "5.10.269",
        "versionType": "semver",
        "lessThanOrEqual": "5.10.*"
      },
      {
        "status": "unaffected",
        "version": "5.15.220",
        "versionType": "semver",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "6.1.187",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.156",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.108",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.49",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.1.13",
        "versionType": "semver",
        "lessThanOrEqual": "7.1.*"
      },
      {
        "status": "unaffected",
        "version": "7.2.3",
        "versionType": "semver",
        "lessThanOrEqual": "7.2.*"
      },
      {
        "status": "unaffected",
        "version": "7.3",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "drivers/target/target_core_fabric_configfs.c",
      "drivers/usb/gadget/function/f_tcm.c",
      "include/target/target_core_fabric.h"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-80854

Source reference: /cveMetadata/cveId

Publisher severity

No explicit severity was provided.

Event
#34869 · Revision 1
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Publisher date
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