{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-90009",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-09-11T19:38:34.781Z",
        "datePublished": "2026-09-16T10:33:17.446Z",
        "dateUpdated": "2026-10-19T08:56:23.130Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-10-19T08:56:23.130Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nscsi: bsg: Fix TOCTOU in io_uring passthrough command setup\n\nscsi_bsg_uring_cmd() reads bsg_uring_cmd from the shared mmap'd SQE.\nUserspace can change a field after we check it and before we use it.\nrequest_len is the sharp case: it can grow past sizeof(scmd->cmnd) after\nthe bound check and overflow scmd->cmnd in copy_from_user().\n\nREAD_ONCE() the SQE fields we check or use into locals before use."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                        "baseScore": 7.8,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:L - scsi_bsg_uring_cmd() is reached only via a local io_uring IORING_OP_URING_CMD on a SCSI BSG device node (/dev/bsg/<h:c:i:l>); io_uring and BSG are local syscall/device paths, not a network protocol handler.\nAC:L - The attacker owns both sides of the TOCTOU: one thread submits the uring_cmd while another rewrites request_len in the shared mmap'd SQE. The inline issue path never copies the SQE first, and scsi_alloc_request() sits between the bound check and copy_from_user, making the race attacker-driven and retryable.\nPR:L - bsg_open() has no capability check; access is only DAC on /dev/bsg/* for ordinary SCSI devices. scsi_cmd_allowed() runs after the overflow. Disk/cdrom group membership and uaccess on removable SCSI/USB devices grant this to unprivileged local users without init-namespace root.\nUI:N - The attacker opens the BSG node, creates an io_uring ring with SQE128/CQE32, and submits the racing passthrough command themselves; no victim action is required.\nS:U - The overflow corrupts the blk-mq scsi_cmnd PDU and adjacent kernel heap in the same host kernel security authority, enabling local privilege escalation rather than a VM, IOMMU, or sandbox boundary crossing.\nC:H - copy_from_user() overflows the 32-byte scmd->cmnd into scsi_cmnd pointer fields (sdb, sense_buffer, host_scribble) and adjacent heap with attacker-controlled bytes, which can be groomed into kernel memory disclosure.\nI:H - The same attacker-controlled heap overflow overwrites kernel pointers and adjacent blk-mq request objects, providing a write primitive exploitable for control-flow hijacking and privilege escalation.\nA:H - A large request_len smash or later use of corrupted scsi_cmnd pointers causes a kernel oops or panic; even a failed copy_from_user still writes through kernel memory until a fault, then frees the corrupted request."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/scsi/scsi_bsg.c"
                    ],
                    "versions": [
                        {
                            "version": "7b6d3255e7f8c6df2d21504c47808e3ce84649ac",
                            "lessThan": "f033530105aa73d82c121d54b57f358e4865d2f4",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "7b6d3255e7f8c6df2d21504c47808e3ce84649ac",
                            "lessThan": "4b3c5965fca99f62d31c963294bd5b23cc488e97",
                            "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/scsi/scsi_bsg.c"
                    ],
                    "versions": [
                        {
                            "version": "7.1",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "7.1",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2.5",
                            "lessThanOrEqual": "7.2.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.3",
                            "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": "7.1",
                                    "versionEndExcluding": "7.2.5"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "7.1",
                                    "versionEndExcluding": "7.3"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/f033530105aa73d82c121d54b57f358e4865d2f4"
                },
                {
                    "url": "https://git.kernel.org/stable/c/4b3c5965fca99f62d31c963294bd5b23cc488e97"
                }
            ],
            "title": "scsi: bsg: Fix TOCTOU in io_uring passthrough command setup",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}