CVE-2026-74617 (GCVE-0-2026-74617)
Vulnerability from cvelistv5
Published
2026-08-22 15:32
Modified
2026-08-25 05:40
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
dibs: initialise dibs->lock in dibs_dev_alloc()
dibs->lock is initialised by dibs_dev_add(), but a dibs device can
already take interrupts before that call: ism_probe() runs
ism_dev_init(), and hence request_irq(), before it calls
dibs_dev_add(). No client can have registered a dmb at that point, so
no dmb interrupt can occur, but a GID event interrupt can, and
ism_handle_irq() takes dibs->lock unconditionally on entry, before it
inspects anything else.
Initialise the lock in dibs_dev_alloc() instead, so that it is valid as
soon as a driver can publish the device to its interrupt handler.
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/dibs/dibs_main.c",
"include/linux/dibs.h"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "fe79571f40434b257d68cbfb7b3ae93a794d8a11",
"status": "affected",
"version": "cc21191b584c6f7836b0f10774f8278b7cbfba10",
"versionType": "git"
},
{
"lessThan": "2926031acba100d0c18fcfaa7a2ed29609318848",
"status": "affected",
"version": "cc21191b584c6f7836b0f10774f8278b7cbfba10",
"versionType": "git"
},
{
"lessThan": "c27e360545373b7aee9862a5beef3b9fb3df0c25",
"status": "affected",
"version": "cc21191b584c6f7836b0f10774f8278b7cbfba10",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/dibs/dibs_main.c",
"include/linux/dibs.h"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.18"
},
{
"lessThan": "6.18",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.45",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.9",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.45",
"versionStartIncluding": "6.18",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.9",
"versionStartIncluding": "6.18",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "6.18",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndibs: initialise dibs-\u003elock in dibs_dev_alloc()\n\ndibs-\u003elock is initialised by dibs_dev_add(), but a dibs device can\nalready take interrupts before that call: ism_probe() runs\nism_dev_init(), and hence request_irq(), before it calls\ndibs_dev_add(). No client can have registered a dmb at that point, so\nno dmb interrupt can occur, but a GID event interrupt can, and\nism_handle_irq() takes dibs-\u003elock unconditionally on entry, before it\ninspects anything else.\n\nInitialise the lock in dibs_dev_alloc() instead, so that it is valid as\nsoon as a driver can publish the device to its interrupt handler."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 9.8,
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:N - On IBM Z SMC-D systems, a remote networked peer on the shared ISM fabric can emit GID/IEQ fabric events that raise ISM MSI interrupts during ism_probe, reaching ism_handle_irq() without any local syscall or ioctl on the victim.\nAC:L - The attacker controls timing by repeatedly sending ISM GID/IEQ fabric events (or coordinating with victim reboot/module reprobe) to hit the probe window between request_irq() and dibs_dev_add(), rather than depending on uncontrollable memory layout.\nPR:N - Exploitation is driven by ISM hardware interrupts from fabric events and does not require local credentials, capabilities, or namespaces on the victim; a remote/co-tenant ISM fabric peer can trigger the IRQ path during device bring-up.\nUI:N - The race occurs automatically during kernel boot or ISM driver probe when fabric GID events arrive; no victim user action such as mounting a filesystem or opening a device node is required.\nS:U - The flaw corrupts kernel driver state via an uninitialized spinlock in IRQ context but does not cross a VM, IOMMU, or sandbox security boundary; impact remains within kernel privilege.\nC:H - Calling spin_lock() on an uninitialized dibs-\u003elock is undefined behavior that can corrupt lock metadata and adjacent dibs_dev fields, creating a memory-safety primitive that can be leveraged for arbitrary kernel memory disclosure.\nI:H - Broken spinlock initialization can permit unsafe concurrent access to dibs_dev state and enable arbitrary kernel memory writes or control-flow hijacking, not merely a clean denial of service.\nA:H - Taking an uninitialized spinlock in ism_handle_irq() can trigger kernel BUG/oops/panic or wedge ISM interrupt handling, causing a high-severity system crash or hang on affected IBM Z hosts."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-25T05:40:44.661Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/fe79571f40434b257d68cbfb7b3ae93a794d8a11"
},
{
"url": "https://git.kernel.org/stable/c/2926031acba100d0c18fcfaa7a2ed29609318848"
},
{
"url": "https://git.kernel.org/stable/c/c27e360545373b7aee9862a5beef3b9fb3df0c25"
}
],
"title": "dibs: initialise dibs-\u003elock in dibs_dev_alloc()",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-74617",
"datePublished": "2026-08-22T15:32:02.049Z",
"dateReserved": "2026-08-15T05:44:03.920Z",
"dateUpdated": "2026-08-25T05:40:44.661Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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