{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-72085",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-08-09T03:40:39.904Z",
        "datePublished": "2026-08-15T05:52:33.521Z",
        "dateUpdated": "2026-08-15T05:52:33.521Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-15T05:52:33.521Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: xen: scsiback: Free unsubmitted command instead of double-putting it\n\nscsiback_get_pend_req() obtains a command tag and returns a vscsibk_pend\nwhose embedded se_cmd has only been memset to 0, so its cmd_kref is 0;\nthe se_cmd is initialised (kref_init() via target_init_cmd()) only\nlater, in scsiback_cmd_exec(), on the successful VSCSIIF_ACT_SCSI_CDB\npath. The two error paths in scsiback_do_cmd_fn() taken before the\ncommand is submitted -- a failed scsiback_gnttab_data_map() and an\nunknown ring_req.act -- call\ntransport_generic_free_cmd(&pending_req->se_cmd, 0), which kref_put()s a\nrefcount of 0. That underflows it (\"refcount_t: underflow;\nuse-after-free\") and, as the release function is not run, leaks the\ncommand tag.\n\nImpact: a pvSCSI guest can leak every command tag of a LUN's session,\nstopping the LUN, by submitting requests with a bad grant reference or\nan unknown request type; under panic_on_warn the refcount underflow\npanics the host.\n\nAdd a helper that just returns the tag with target_free_tag() and sends\nthe error response. It frees the tag while the v2p reference still pins\nthe session, and snapshots the response fields beforehand because\nfreeing the tag can let another ring reuse the pending_req slot."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/xen/xen-scsiback.c"
                    ],
                    "versions": [
                        {
                            "version": "2dbcdf33dbf61f44b29adb52338282c3d7840d0e",
                            "lessThan": "9c0f6894982b1f13bda220707497b25ac9c95bdb",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "2dbcdf33dbf61f44b29adb52338282c3d7840d0e",
                            "lessThan": "a13b789497a7fdd27d4d63f5c69d23db706ef0fe",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "2dbcdf33dbf61f44b29adb52338282c3d7840d0e",
                            "lessThan": "fa588f28401102652068c4cc75e135507f4b5106",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "2dbcdf33dbf61f44b29adb52338282c3d7840d0e",
                            "lessThan": "fcd64d4d97af5d9736f31040f8ed8cd4c17e4c45",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "2dbcdf33dbf61f44b29adb52338282c3d7840d0e",
                            "lessThan": "f1516c56ac540da1769f264c3cfefe4499548a5d",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "2dbcdf33dbf61f44b29adb52338282c3d7840d0e",
                            "lessThan": "1e97c404e44991fb087c38ccd7414f2d326f9b74",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "2dbcdf33dbf61f44b29adb52338282c3d7840d0e",
                            "lessThan": "ca978f8a93d4d36841839bf2847d29b88c2591d6",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/xen/xen-scsiback.c"
                    ],
                    "versions": [
                        {
                            "version": "4.6",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "4.6",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.15.212",
                            "lessThanOrEqual": "5.15.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.1.178",
                            "lessThanOrEqual": "6.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.145",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.97",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.40",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1.5",
                            "lessThanOrEqual": "7.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2-rc4",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.6",
                                    "versionEndExcluding": "5.15.212"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.6",
                                    "versionEndExcluding": "6.1.178"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.6",
                                    "versionEndExcluding": "6.6.145"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.6",
                                    "versionEndExcluding": "6.12.97"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.6",
                                    "versionEndExcluding": "6.18.40"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.6",
                                    "versionEndExcluding": "7.1.5"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.6",
                                    "versionEndExcluding": "7.2-rc4"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/9c0f6894982b1f13bda220707497b25ac9c95bdb"
                },
                {
                    "url": "https://git.kernel.org/stable/c/a13b789497a7fdd27d4d63f5c69d23db706ef0fe"
                },
                {
                    "url": "https://git.kernel.org/stable/c/fa588f28401102652068c4cc75e135507f4b5106"
                },
                {
                    "url": "https://git.kernel.org/stable/c/fcd64d4d97af5d9736f31040f8ed8cd4c17e4c45"
                },
                {
                    "url": "https://git.kernel.org/stable/c/f1516c56ac540da1769f264c3cfefe4499548a5d"
                },
                {
                    "url": "https://git.kernel.org/stable/c/1e97c404e44991fb087c38ccd7414f2d326f9b74"
                },
                {
                    "url": "https://git.kernel.org/stable/c/ca978f8a93d4d36841839bf2847d29b88c2591d6"
                }
            ],
            "title": "scsi: xen: scsiback: Free unsubmitted command instead of double-putting it",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}