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CVE-2026-80854 (GCVE-0-2026-80854)

Vulnerability from cvelistv5 – Published: 2026-09-04 15:55 – Updated: 2026-09-04 15:55
VLAI
Title
usb: gadget: f_tcm: keep port count until LUN teardown completes
Summary
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.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: c52661d60f636d17e26ad834457db333bd1df494 , < c494c5562ca69b61a82f566e3b87a445d2c28929 (git)
Affected: c52661d60f636d17e26ad834457db333bd1df494 , < c1f359d9a5efed458946063de65ddbeaacc4f165 (git)
Affected: c52661d60f636d17e26ad834457db333bd1df494 , < 178f59a0bccd3f66cdfa5184310f31a58b7257c4 (git)
Affected: c52661d60f636d17e26ad834457db333bd1df494 , < ad6f0375d2e93a1d8c015463e5e92dfcb26e311b (git)
Affected: c52661d60f636d17e26ad834457db333bd1df494 , < 2efbfd42441d3ef8137aff2d59e9835e1d5ae780 (git)
Affected: c52661d60f636d17e26ad834457db333bd1df494 , < 85aa61fedcb4eb13f3dc5db73f6dc359f41f5d95 (git)
Affected: c52661d60f636d17e26ad834457db333bd1df494 , < bbd6aa311a9f4dd17822c7557451458d3d2e980b (git)
Affected: c52661d60f636d17e26ad834457db333bd1df494 , < eaa96a8458f54d6cf0954242ab8b1df2a6fccafa (git)
Affected: c52661d60f636d17e26ad834457db333bd1df494 , < c39d0916da47d94909391876c9e5bd429ea7b1b9 (git)
guessed Create a notification for this product.
Linux Linux Affected: 3.5
Unaffected: 0 , < 3.5 (semver)
Unaffected: 5.10.269 , ≤ 5.10.* (semver)
Unaffected: 5.15.220 , ≤ 5.15.* (semver)
Unaffected: 6.1.187 , ≤ 6.1.* (semver)
Unaffected: 6.6.156 , ≤ 6.6.* (semver)
Unaffected: 6.12.108 , ≤ 6.12.* (semver)
Unaffected: 6.18.49 , ≤ 6.18.* (semver)
Unaffected: 7.1.13 , ≤ 7.1.* (semver)
Unaffected: 7.2.3 , ≤ 7.2.* (semver)
Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
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{
  "containers": {
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        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/target/target_core_fabric_configfs.c",
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            "include/target/target_core_fabric.h"
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          "vendor": "Linux",
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              "versionType": "git"
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        {
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          "product": "Linux",
          "programFiles": [
            "drivers/target/target_core_fabric_configfs.c",
            "drivers/usb/gadget/function/f_tcm.c",
            "include/target/target_core_fabric.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "status": "affected",
              "version": "3.5"
            },
            {
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              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
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              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.269",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.220",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.187",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.156",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.108",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.49",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.13",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.269",
                  "versionStartIncluding": "3.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.220",
                  "versionStartIncluding": "3.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.187",
                  "versionStartIncluding": "3.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.156",
                  "versionStartIncluding": "3.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.108",
                  "versionStartIncluding": "3.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.49",
                  "versionStartIncluding": "3.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.13",
                  "versionStartIncluding": "3.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.3",
                  "versionStartIncluding": "3.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "3.5",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: f_tcm: keep port count until LUN teardown completes\n\ntcm_usbg_drop_nexus() permits session removal once tpg_port_count\nreaches zero. However, usbg_port_unlink() currently decrements that\ncount from the fabric_pre_unlink() callback, before core_dev_del_lun()\nwaits for active se_lun references to drain.\n\nIf removal of the last LUN races a nexus removal, the latter can observe\na zero port count and call target_remove_session(). This frees\nsess_cmd_map while an in-flight struct usbg_cmd, including its work item,\ncan still be accessed.\n\nOverlapping the last-LUN unlink with nexus removal reproduces this\nlifetime violation as a DEBUG_OBJECTS \"free active\" warning for\nusbg_cmd_work, followed by a target-core BUG/Oops.\n\nThe generic target-core unlink path has no callback after\ncore_dev_del_lun() completes. Add an optional fabric_post_unlink()\ncallback and use it for the f_tcm port count. The count now remains\nnonzero until core_dev_del_lun() has finished draining active LUN\nreferences, preventing nexus removal from freeing the session during\ncommand completion."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-04T15:55:06.478Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/c494c5562ca69b61a82f566e3b87a445d2c28929"
        },
        {
          "url": "https://git.kernel.org/stable/c/c1f359d9a5efed458946063de65ddbeaacc4f165"
        },
        {
          "url": "https://git.kernel.org/stable/c/178f59a0bccd3f66cdfa5184310f31a58b7257c4"
        },
        {
          "url": "https://git.kernel.org/stable/c/ad6f0375d2e93a1d8c015463e5e92dfcb26e311b"
        },
        {
          "url": "https://git.kernel.org/stable/c/2efbfd42441d3ef8137aff2d59e9835e1d5ae780"
        },
        {
          "url": "https://git.kernel.org/stable/c/85aa61fedcb4eb13f3dc5db73f6dc359f41f5d95"
        },
        {
          "url": "https://git.kernel.org/stable/c/bbd6aa311a9f4dd17822c7557451458d3d2e980b"
        },
        {
          "url": "https://git.kernel.org/stable/c/eaa96a8458f54d6cf0954242ab8b1df2a6fccafa"
        },
        {
          "url": "https://git.kernel.org/stable/c/c39d0916da47d94909391876c9e5bd429ea7b1b9"
        }
      ],
      "title": "usb: gadget: f_tcm: keep port count until LUN teardown completes",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-80854",
    "datePublished": "2026-09-04T15:55:06.478Z",
    "dateReserved": "2026-08-26T14:34:25.797Z",
    "dateUpdated": "2026-09-04T15:55:06.478Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-80854",
      "date": "2026-09-14",
      "epss": "0.00182",
      "percentile": "0.07916"
    },
    "microsoft_vex": {
      "current_release_date": "2026-09-09T01:52:54.000Z",
      "cve": "CVE-2026-80854",
      "id": "msrc_CVE-2026-80854",
      "initial_release_date": "2026-09-06T05:08:29.000Z",
      "product_status:known_not_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "usb: gadget: f_tcm: keep port count until LUN teardown completes",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-80854.json",
      "version": "3"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-80854\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-09-04T16:18:14.353\",\"lastModified\":\"2026-09-04T16:18:14.353\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nusb: gadget: f_tcm: keep port count until LUN teardown completes\\n\\ntcm_usbg_drop_nexus() permits session removal once tpg_port_count\\nreaches zero. However, usbg_port_unlink() currently decrements that\\ncount from the fabric_pre_unlink() callback, before core_dev_del_lun()\\nwaits for active se_lun references to drain.\\n\\nIf removal of the last LUN races a nexus removal, the latter can observe\\na zero port count and call target_remove_session(). This frees\\nsess_cmd_map while an in-flight struct usbg_cmd, including its work item,\\ncan still be accessed.\\n\\nOverlapping the last-LUN unlink with nexus removal reproduces this\\nlifetime violation as a DEBUG_OBJECTS \\\"free active\\\" warning for\\nusbg_cmd_work, followed by a target-core BUG/Oops.\\n\\nThe generic target-core unlink path has no callback after\\ncore_dev_del_lun() completes. Add an optional fabric_post_unlink()\\ncallback and use it for the f_tcm port count. The count now remains\\nnonzero until core_dev_del_lun() has finished draining active LUN\\nreferences, preventing nexus removal from freeing the session during\\ncommand completion.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/target/target_core_fabric_configfs.c\",\"drivers/usb/gadget/function/f_tcm.c\",\"include/target/target_core_fabric.h\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"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\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/target/target_core_fabric_configfs.c\",\"drivers/usb/gadget/function/f_tcm.c\",\"include/target/target_core_fabric.h\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"3.5\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"3.5\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.269\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.220\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.187\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.156\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.108\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.49\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.13\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2.3\",\"lessThanOrEqual\":\"7.2.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.3-rc1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/178f59a0bccd3f66cdfa5184310f31a58b7257c4\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/2efbfd42441d3ef8137aff2d59e9835e1d5ae780\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/85aa61fedcb4eb13f3dc5db73f6dc359f41f5d95\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/ad6f0375d2e93a1d8c015463e5e92dfcb26e311b\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/bbd6aa311a9f4dd17822c7557451458d3d2e980b\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/c1f359d9a5efed458946063de65ddbeaacc4f165\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/c39d0916da47d94909391876c9e5bd429ea7b1b9\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/c494c5562ca69b61a82f566e3b87a445d2c28929\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/eaa96a8458f54d6cf0954242ab8b1df2a6fccafa\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-10T01:50:29Z",
      "cve": "CVE-2026-80854",
      "id": "CVE-2026-80854",
      "initial_release_date": "2026-09-05T00:26:06Z",
      "product_status:known_affected": "337",
      "product_status:known_not_affected": "4",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-80854",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-80854.json",
      "version": "4"
    }
  }
}



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