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CVE-2026-72086 (GCVE-0-2026-72086)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:52 – Updated: 2026-08-17 05:07
VLAI
Title
scsi: xen: scsiback: Free the command tag on the TMR submit-failure path
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.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 2dbcdf33dbf61f44b29adb52338282c3d7840d0e , < 4567ce79fe2f84c3dcc3a91b22a377cf482d33ad (git)
Affected: 2dbcdf33dbf61f44b29adb52338282c3d7840d0e , < 6c01f0439098f00a64b246dc27479602201382f7 (git)
Affected: 2dbcdf33dbf61f44b29adb52338282c3d7840d0e , < 18d4f86816592586b38513543b5e1f9553bc271f (git)
Affected: 2dbcdf33dbf61f44b29adb52338282c3d7840d0e , < fbc1bdede66d0f2cde83b75d6524ce1a815bb69f (git)
Affected: 2dbcdf33dbf61f44b29adb52338282c3d7840d0e , < 255fb7b0cdc947b1c01929c7f133281342a3a6b5 (git)
Affected: 2dbcdf33dbf61f44b29adb52338282c3d7840d0e , < 1357fb32d42ad8da193e6da285f09e6452feabda (git)
Affected: 2dbcdf33dbf61f44b29adb52338282c3d7840d0e , < 66aefc277ebb796ec285d550305535dc3fc0179f (git)
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Linux Linux Affected: 4.6
Unaffected: 0 , < 4.6 (semver)
Unaffected: 5.15.212 , ≤ 5.15.* (semver)
Unaffected: 6.1.178 , ≤ 6.1.* (semver)
Unaffected: 6.6.145 , ≤ 6.6.* (semver)
Unaffected: 6.12.97 , ≤ 6.12.* (semver)
Unaffected: 6.18.40 , ≤ 6.18.* (semver)
Unaffected: 7.1.5 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
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{
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          "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."
        }
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    "cveId": "CVE-2026-72086",
    "datePublished": "2026-08-15T05:52:34.822Z",
    "dateReserved": "2026-08-09T03:40:39.905Z",
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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.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/xen/xen-scsiback.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"2dbcdf33dbf61f44b29adb52338282c3d7840d0e\",\"lessThan\":\"4567ce79fe2f84c3dcc3a91b22a377cf482d33ad\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"2dbcdf33dbf61f44b29adb52338282c3d7840d0e\",\"lessThan\":\"6c01f0439098f00a64b246dc27479602201382f7\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"2dbcdf33dbf61f44b29adb52338282c3d7840d0e\",\"lessThan\":\"18d4f86816592586b38513543b5e1f9553bc271f\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"2dbcdf33dbf61f44b29adb52338282c3d7840d0e\",\"lessThan\":\"fbc1bdede66d0f2cde83b75d6524ce1a815bb69f\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"2dbcdf33dbf61f44b29adb52338282c3d7840d0e\",\"lessThan\":\"255fb7b0cdc947b1c01929c7f133281342a3a6b5\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"2dbcdf33dbf61f44b29adb52338282c3d7840d0e\",\"lessThan\":\"1357fb32d42ad8da193e6da285f09e6452feabda\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"2dbcdf33dbf61f44b29adb52338282c3d7840d0e\",\"lessThan\":\"66aefc277ebb796ec285d550305535dc3fc0179f\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/xen/xen-scsiback.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"4.6\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"4.6\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.212\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.178\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.145\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.97\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.40\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.5\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"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\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-17T21:41:24+00:00",
      "cve": "CVE-2026-72086",
      "id": "CVE-2026-72086",
      "initial_release_date": "2026-08-15T00:00:00+00:00",
      "product_status:known_not_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: scsi: xen: scsiback: Free the command tag on the TMR submit-failure path",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-72086.json",
      "version": "3"
    }
  }
}



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Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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Detection rules are retrieved from Rulezet.