CVE-2025-40223
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: most: usb: Fix use-after-free in hdm_disconnect hdm_disconnect() calls most_deregister_interface(), which eventually unregisters the MOST interface device with device_unregister(iface->dev). If that drops the last reference, the device core may call release_mdev() immediately while hdm_disconnect() is still executing. The old code also freed several mdev-owned allocations in hdm_disconnect() and then performed additional put_device() calls. Depending on refcount order, this could lead to use-after-free or double-free when release_mdev() ran (or when unregister paths also performed puts). Fix by moving the frees of mdev-owned allocations into release_mdev(), so they happen exactly once when the device is truly released, and by dropping the extra put_device() calls in hdm_disconnect() that are redundant after device_unregister() and most_deregister_interface(). This addresses the KASAN slab-use-after-free reported by syzbot in hdm_disconnect(). See report and stack traces in the bug link below.
Severity
Not scored
CVSS score
Not available
Vulnerability status
Deferred
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2025-12-04 16:16:14.767000
Last modified
2026-10-19 19:10:00.130000
View original CVE JSON
{
"id": "CVE-2025-40223",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2025-12-04T16:16:14.767",
"lastModified": "2026-10-19T19:10:00.130",
"vulnStatus": "Deferred",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmost: usb: Fix use-after-free in hdm_disconnect\n\nhdm_disconnect() calls most_deregister_interface(), which eventually\nunregisters the MOST interface device with device_unregister(iface->dev).\nIf that drops the last reference, the device core may call release_mdev()\nimmediately while hdm_disconnect() is still executing.\n\nThe old code also freed several mdev-owned allocations in\nhdm_disconnect() and then performed additional put_device() calls.\nDepending on refcount order, this could lead to use-after-free or\ndouble-free when release_mdev() ran (or when unregister paths also\nperformed puts).\n\nFix by moving the frees of mdev-owned allocations into release_mdev(),\nso they happen exactly once when the device is truly released, and by\ndropping the extra put_device() calls in hdm_disconnect() that are\nredundant after device_unregister() and most_deregister_interface().\n\nThis addresses the KASAN slab-use-after-free reported by syzbot in\nhdm_disconnect(). See report and stack traces in the bug link below."
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad:\n\nmost: usb: Corrección de uso después de liberación en hdm_disconnect\n\nhdm_disconnect() llama a most_deregister_interface(), que eventualmente anula el registro del dispositivo de interfaz MOST con device_unregister(iface -> dev). Si eso elimina la última referencia, el núcleo del dispositivo puede llamar a release_mdev() inmediatamente mientras hdm_disconnect() todavía se está ejecutando.\n\nEl código antiguo también liberaba varias asignaciones propiedad de mdev en hdm_disconnect() y luego realizaba llamadas put_device() adicionales. Dependiendo del orden del contador de referencias, esto podría llevar a un uso después de liberación o a una doble liberación cuando se ejecutaba release_mdev() (o cuando las rutas de anulación de registro también realizaban puts).\n\nSe corrige moviendo las liberaciones de asignaciones propiedad de mdev a release_mdev(), para que ocurran exactamente una vez cuando el dispositivo se libera verdaderamente, y eliminando las llamadas put_device() adicionales en hdm_disconnect() que son redundantes después de device_unregister() y most_deregister_interface().\n\nEsto aborda el uso después de liberación de slab de KASAN reportado por syzbot en hdm_disconnect(). Ver informe y rastreos de pila en el enlace del error a continuación."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"drivers/most/most_usb.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "97a6f772f36b7f52bcfa56a581bbd2470cffe23d",
"lessThan": "5b5c478f09b1b35e7fe6fc9a1786c9bf6030e831",
"versionType": "git",
"status": "affected"
},
{
"version": "97a6f772f36b7f52bcfa56a581bbd2470cffe23d",
"lessThan": "578eb18cd111addec94c43f61cd4b4429e454809",
"versionType": "git",
"status": "affected"
},
{
"version": "97a6f772f36b7f52bcfa56a581bbd2470cffe23d",
"lessThan": "33daf469f5294b9d07c4fc98216cace9f4f34cc6",
"versionType": "git",
"status": "affected"
},
{
"version": "97a6f772f36b7f52bcfa56a581bbd2470cffe23d",
"lessThan": "72427dc6f87523995f4e6ae35a948bb2992cabce",
"versionType": "git",
"status": "affected"
},
{
"version": "97a6f772f36b7f52bcfa56a581bbd2470cffe23d",
"lessThan": "f93a84ffb884d761a9d4e869ba29c238711e81f1",
"versionType": "git",
"status": "affected"
},
{
"version": "97a6f772f36b7f52bcfa56a581bbd2470cffe23d",
"lessThan": "3a3b8e89c7201c5b3b76ac4a4069d1adde1477d6",
"versionType": "git",
"status": "affected"
},
{
"version": "97a6f772f36b7f52bcfa56a581bbd2470cffe23d",
"lessThan": "4b1270902609ef0d935ed2faa2ea6d122bd148f5",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"drivers/most/most_usb.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "5.9",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.9",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.246",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.196",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.158",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.115",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.56",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.17.6",
"lessThanOrEqual": "6.17.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {},
"references": [
{
"url": "https://git.kernel.org/stable/c/33daf469f5294b9d07c4fc98216cace9f4f34cc6",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/3a3b8e89c7201c5b3b76ac4a4069d1adde1477d6",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/4b1270902609ef0d935ed2faa2ea6d122bd148f5",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/578eb18cd111addec94c43f61cd4b4429e454809",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/5b5c478f09b1b35e7fe6fc9a1786c9bf6030e831",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/72427dc6f87523995f4e6ae35a948bb2992cabce",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/f93a84ffb884d761a9d4e869ba29c238711e81f1",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}