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FKIE_CVE-2026-72086

Vulnerability from fkie_nvd - Published: 2026-08-15 06:21 - Updated: 2026-08-17 06:18
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: scsi: xen: scsiback: Free the command tag on the TMR submit-failure path scsiback_device_action() obtains a command tag in scsiback_get_pend_req() and submits a task-management request with target_submit_tmr(). When target_submit_tmr() fails it returns < 0 and scsiback jumps to the err: label, which sends a response but frees nothing, leaking the tag. Impact: a pvSCSI guest can leak the command tags of a LUN's session, stopping the LUN, by issuing VSCSIIF_ACT_SCSI_ABORT or RESET requests whenever target_submit_tmr() fails. transport_generic_free_cmd() cannot be used here. By the time target_submit_tmr() returns an error it has already run __target_init_cmd() (so se_cmd->cmd_kref is one, not zero), and on its target_get_sess_cmd() error path it has freed se_cmd->se_tmr_req via core_tmr_release_req() while leaving SCF_SCSI_TMR_CDB set and the pointer dangling. Letting the command release run target_free_cmd_mem() would then double-free se_tmr_req. Use the same helper, which returns just the tag, on this path too.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1357fb32d42ad8da193e6da285f09e6452feabda
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/18d4f86816592586b38513543b5e1f9553bc271f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/255fb7b0cdc947b1c01929c7f133281342a3a6b5
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4567ce79fe2f84c3dcc3a91b22a377cf482d33ad
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/66aefc277ebb796ec285d550305535dc3fc0179f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6c01f0439098f00a64b246dc27479602201382f7
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/fbc1bdede66d0f2cde83b75d6524ce1a815bb69f
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/xen/xen-scsiback.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "4567ce79fe2f84c3dcc3a91b22a377cf482d33ad",
              "status": "affected",
              "version": "2dbcdf33dbf61f44b29adb52338282c3d7840d0e",
              "versionType": "git"
            },
            {
              "lessThan": "6c01f0439098f00a64b246dc27479602201382f7",
              "status": "affected",
              "version": "2dbcdf33dbf61f44b29adb52338282c3d7840d0e",
              "versionType": "git"
            },
            {
              "lessThan": "18d4f86816592586b38513543b5e1f9553bc271f",
              "status": "affected",
              "version": "2dbcdf33dbf61f44b29adb52338282c3d7840d0e",
              "versionType": "git"
            },
            {
              "lessThan": "fbc1bdede66d0f2cde83b75d6524ce1a815bb69f",
              "status": "affected",
              "version": "2dbcdf33dbf61f44b29adb52338282c3d7840d0e",
              "versionType": "git"
            },
            {
              "lessThan": "255fb7b0cdc947b1c01929c7f133281342a3a6b5",
              "status": "affected",
              "version": "2dbcdf33dbf61f44b29adb52338282c3d7840d0e",
              "versionType": "git"
            },
            {
              "lessThan": "1357fb32d42ad8da193e6da285f09e6452feabda",
              "status": "affected",
              "version": "2dbcdf33dbf61f44b29adb52338282c3d7840d0e",
              "versionType": "git"
            },
            {
              "lessThan": "66aefc277ebb796ec285d550305535dc3fc0179f",
              "status": "affected",
              "version": "2dbcdf33dbf61f44b29adb52338282c3d7840d0e",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/xen/xen-scsiback.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.6"
            },
            {
              "lessThan": "4.6",
              "status": "unaffected",
              "version": "0",
              "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": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "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\nscsi: xen: scsiback: Free the command tag on the TMR submit-failure path\n\nscsiback_device_action() obtains a command tag in\nscsiback_get_pend_req() and submits a task-management request with\ntarget_submit_tmr(). When target_submit_tmr() fails it returns \u003c 0 and\nscsiback jumps to the err: label, which sends a response but frees\nnothing, leaking the tag.\n\nImpact: a pvSCSI guest can leak the command tags of a LUN\u0027s session,\nstopping the LUN, by issuing VSCSIIF_ACT_SCSI_ABORT or RESET requests\nwhenever target_submit_tmr() fails.\n\ntransport_generic_free_cmd() cannot be used here. By the time\ntarget_submit_tmr() returns an error it has already run\n__target_init_cmd() (so se_cmd-\u003ecmd_kref is one, not zero), and on its\ntarget_get_sess_cmd() error path it has freed se_cmd-\u003ese_tmr_req via\ncore_tmr_release_req() while leaving SCF_SCSI_TMR_CDB set and the\npointer dangling. Letting the command release run target_free_cmd_mem()\nwould then double-free se_tmr_req.\n\nUse the same helper, which returns just the tag, on this path too."
    }
  ],
  "id": "CVE-2026-72086",
  "lastModified": "2026-08-17T06:18:07.513",
  "metrics": {},
  "published": "2026-08-15T06:21:22.593",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1357fb32d42ad8da193e6da285f09e6452feabda"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/18d4f86816592586b38513543b5e1f9553bc271f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/255fb7b0cdc947b1c01929c7f133281342a3a6b5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4567ce79fe2f84c3dcc3a91b22a377cf482d33ad"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/66aefc277ebb796ec285d550305535dc3fc0179f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6c01f0439098f00a64b246dc27479602201382f7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fbc1bdede66d0f2cde83b75d6524ce1a815bb69f"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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