CVE-2026-90009 (GCVE-0-2026-90009)
Vulnerability from cvelistv5 – Published: 2026-09-16 10:33 – Updated: 2026-09-16 14:41
VLAI
EPSS
VEX
Title
scsi: bsg: Fix TOCTOU in io_uring passthrough command setup
Summary
In the Linux kernel, the following vulnerability has been resolved:
scsi: bsg: Fix TOCTOU in io_uring passthrough command setup
scsi_bsg_uring_cmd() reads bsg_uring_cmd from the shared mmap'd SQE.
Userspace can change a field after we check it and before we use it.
request_len is the sharp case: it can grow past sizeof(scmd->cmnd) after
the bound check and overflow scmd->cmnd in copy_from_user().
READ_ONCE() the SQE fields we check or use into locals before use.
Severity
7.8 (High)
Assigner
References
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
7b6d3255e7f8c6df2d21504c47808e3ce84649ac , < f033530105aa73d82c121d54b57f358e4865d2f4
(git)
Affected: 7b6d3255e7f8c6df2d21504c47808e3ce84649ac , < 4b3c5965fca99f62d31c963294bd5b23cc488e97 (git) |
guessed | |
| Linux | Linux |
Affected:
7.1
Unaffected: 0 , < 7.1 (semver) Unaffected: 7.2.5 , ≤ 7.2.* (semver) Unaffected: 7.3-rc2 , ≤ * (original_commit_for_fix) |
guessed |
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/scsi/scsi_bsg.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "f033530105aa73d82c121d54b57f358e4865d2f4",
"status": "affected",
"version": "7b6d3255e7f8c6df2d21504c47808e3ce84649ac",
"versionType": "git"
},
{
"lessThan": "4b3c5965fca99f62d31c963294bd5b23cc488e97",
"status": "affected",
"version": "7b6d3255e7f8c6df2d21504c47808e3ce84649ac",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/scsi/scsi_bsg.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "7.1"
},
{
"lessThan": "7.1",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3-rc2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2.5",
"versionStartIncluding": "7.1",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.3-rc2",
"versionStartIncluding": "7.1",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"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\u0027d 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-\u003ecmnd) after\nthe bound check and overflow scmd-\u003ecmnd in copy_from_user().\n\nREAD_ONCE() the SQE fields we check or use into locals before use."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"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/\u003ch:c:i:l\u003e); 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\u0027d 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-\u003ecmnd 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."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-09-16T14:41:25.065Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"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"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-90009",
"datePublished": "2026-09-16T10:33:17.446Z",
"dateReserved": "2026-09-11T19:38:34.781Z",
"dateUpdated": "2026-09-16T14:41:25.065Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"nvd": "{\"cve\":{\"id\":\"CVE-2026-90009\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-09-16T11:17:13.553\",\"lastModified\":\"2026-09-16T15:18:24.553\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"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\u0027d 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-\u003ecmnd) after\\nthe bound check and overflow scmd-\u003ecmnd in copy_from_user().\\n\\nREAD_ONCE() the SQE fields we check or use into locals before use.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/scsi/scsi_bsg.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"7b6d3255e7f8c6df2d21504c47808e3ce84649ac\",\"lessThan\":\"f033530105aa73d82c121d54b57f358e4865d2f4\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"7b6d3255e7f8c6df2d21504c47808e3ce84649ac\",\"lessThan\":\"4b3c5965fca99f62d31c963294bd5b23cc488e97\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/scsi/scsi_bsg.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"7.1\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"7.1\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2.5\",\"lessThanOrEqual\":\"7.2.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.3-rc2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"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\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/4b3c5965fca99f62d31c963294bd5b23cc488e97\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/f033530105aa73d82c121d54b57f358e4865d2f4\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
}
}
Loading…
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
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.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
Loading…