FKIE_CVE-2026-64331
Vulnerability from fkie_nvd - Published: 2026-07-25 10:17 - Updated: 2026-11-06 17:18
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
usbip: vudc: fix NULL deref in vep_dequeue()
vep_alloc_request() wasn't initializing vrequest->udc, so cancellations
on the FunctionFS AIO path were arriving in vep_dequeue without a valid
UDC reference.
Since vrequest->udc is never actually properly used anywhere, we opt to
remove it, and update vep_dequeue to obtain a reference to the udc with
ep_to_vudc(), consistent with the other vep_ ops.
AFAICT this bug has existed for ~10 years. Seems that nobody has really
stressed the FunctionFS AIO path on usbip's vudc.
I tested this fix in a QEMU aarch64 guest driving FunctionFS endpoints
via AIO. Before the fix, running `usbip attach` from the host would
cause the guest to oops with the following backtrace:
Call trace:
vep_dequeue+0x1c/0xe4 (P)
usb_ep_dequeue+0x14/0x20
ffs_aio_cancel+0x24/0x34
__arm64_sys_io_cancel+0xb0/0x124
do_el0_svc+0x68/0x100
el0_svc+0x18/0x5c
el0t_64_sync_handler+0x98/0xdc
el0t_64_sync+0x154/0x158
References
Impacted products
| Vendor | Product | Version | |
|---|---|---|---|
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | 7.2 | |
| linux | linux_kernel | 7.2 |
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/usb/usbip/vudc.h",
"drivers/usb/usbip/vudc_dev.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "9858c91d9ee6a13c45311569039413729fc9b757",
"status": "affected",
"version": "b6a0ca11186759ad7045d68a5447b1e89f658384",
"versionType": "git"
},
{
"lessThan": "1226293ec9bed3d4cc5b05eeeb811d315ca51652",
"status": "affected",
"version": "b6a0ca11186759ad7045d68a5447b1e89f658384",
"versionType": "git"
},
{
"lessThan": "3750f75f29f99c0223601e2ee73ad084adec47bd",
"status": "affected",
"version": "b6a0ca11186759ad7045d68a5447b1e89f658384",
"versionType": "git"
},
{
"lessThan": "d0ebf9cc7c2ddf95a7cfc654b940bdacb7edde97",
"status": "affected",
"version": "b6a0ca11186759ad7045d68a5447b1e89f658384",
"versionType": "git"
},
{
"lessThan": "0025276175fbbe0dcbf3f84d090b0adee769e9d9",
"status": "affected",
"version": "b6a0ca11186759ad7045d68a5447b1e89f658384",
"versionType": "git"
},
{
"lessThan": "347b59e9f96719d89b6ef555d02a18ada1a5846f",
"status": "affected",
"version": "b6a0ca11186759ad7045d68a5447b1e89f658384",
"versionType": "git"
},
{
"lessThan": "0443e4416aa1ee97748d1ed904eaf3352c60045e",
"status": "affected",
"version": "b6a0ca11186759ad7045d68a5447b1e89f658384",
"versionType": "git"
},
{
"lessThan": "c5371e0b91b24159a3ebaa61e70b0980bcf03c0a",
"status": "affected",
"version": "b6a0ca11186759ad7045d68a5447b1e89f658384",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/usb/usbip/vudc.h",
"drivers/usb/usbip/vudc_dev.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.7"
},
{
"lessThan": "4.7",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.261",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.212",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.96",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.39",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.4",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"configurations": [
{
"nodes": [
{
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{
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{
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],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nusbip: vudc: fix NULL deref in vep_dequeue()\n\nvep_alloc_request() wasn\u0027t initializing vrequest-\u003eudc, so cancellations\non the FunctionFS AIO path were arriving in vep_dequeue without a valid\nUDC reference.\n\nSince vrequest-\u003eudc is never actually properly used anywhere, we opt to\nremove it, and update vep_dequeue to obtain a reference to the udc with\nep_to_vudc(), consistent with the other vep_ ops.\n\nAFAICT this bug has existed for ~10 years. Seems that nobody has really\nstressed the FunctionFS AIO path on usbip\u0027s vudc.\n\nI tested this fix in a QEMU aarch64 guest driving FunctionFS endpoints\nvia AIO. Before the fix, running `usbip attach` from the host would\ncause the guest to oops with the following backtrace:\n\nCall trace:\n vep_dequeue+0x1c/0xe4 (P)\n usb_ep_dequeue+0x14/0x20\n ffs_aio_cancel+0x24/0x34\n __arm64_sys_io_cancel+0xb0/0x124\n do_el0_svc+0x68/0x100\n el0_svc+0x18/0x5c\n el0t_64_sync_handler+0x98/0xdc\n el0t_64_sync+0x154/0x158"
}
],
"id": "CVE-2026-64331",
"lastModified": "2026-11-06T17:18:48.510",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 5.5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 3.6,
"source": "nvd@nist.gov",
"type": "Primary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-64331",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-11-06T16:35:21.455334Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-07-25T10:17:14.813",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/0025276175fbbe0dcbf3f84d090b0adee769e9d9"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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},
{
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"url": "https://git.kernel.org/stable/c/1226293ec9bed3d4cc5b05eeeb811d315ca51652"
},
{
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"url": "https://git.kernel.org/stable/c/347b59e9f96719d89b6ef555d02a18ada1a5846f"
},
{
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"url": "https://git.kernel.org/stable/c/3750f75f29f99c0223601e2ee73ad084adec47bd"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
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"url": "https://git.kernel.org/stable/c/9858c91d9ee6a13c45311569039413729fc9b757"
},
{
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}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Analyzed",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-476"
}
],
"source": "nvd@nist.gov",
"type": "Primary"
}
]
}
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| Author | Source | Type | Date | Other |
|---|
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Browse all ATT&CK techniques and the vulnerabilities related to each.
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