CVE-2025-68339
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: atm/fore200e: Fix possible data race in fore200e_open() Protect access to fore200e->available_cell_rate with rate_mtx lock in the error handling path of fore200e_open() to prevent a data race. The field fore200e->available_cell_rate is a shared resource used to track available bandwidth. It is concurrently accessed by fore200e_open(), fore200e_close(), and fore200e_change_qos(). In fore200e_open(), the lock rate_mtx is correctly held when subtracting vcc->qos.txtp.max_pcr from available_cell_rate to reserve bandwidth. However, if the subsequent call to fore200e_activate_vcin() fails, the function restores the reserved bandwidth by adding back to available_cell_rate without holding the lock. This introduces a race condition because available_cell_rate is a global device resource shared across all VCCs. If the error path in fore200e_open() executes concurrently with operations like fore200e_close() or fore200e_change_qos() on other VCCs, a read-modify-write race occurs. Specifically, the error path reads the rate without the lock. If another CPU acquires the lock and modifies the rate (e.g., releasing bandwidth in fore200e_close()) between this read and the subsequent write, the error path will overwrite the concurrent update with a stale value. This results in incorrect bandwidth accounting.
Severity
Not scored
CVSS score
Not available
Vulnerability status
Deferred
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2025-12-23 14:16:40.477000
Last modified
2026-10-19 21:10:00.160000
View original CVE JSON
{
"id": "CVE-2025-68339",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2025-12-23T14:16:40.477",
"lastModified": "2026-10-19T21:10:00.160",
"vulnStatus": "Deferred",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\natm/fore200e: Fix possible data race in fore200e_open()\n\nProtect access to fore200e->available_cell_rate with rate_mtx lock in the\nerror handling path of fore200e_open() to prevent a data race.\n\nThe field fore200e->available_cell_rate is a shared resource used to track\navailable bandwidth. It is concurrently accessed by fore200e_open(),\nfore200e_close(), and fore200e_change_qos().\n\nIn fore200e_open(), the lock rate_mtx is correctly held when subtracting\nvcc->qos.txtp.max_pcr from available_cell_rate to reserve bandwidth.\nHowever, if the subsequent call to fore200e_activate_vcin() fails, the\nfunction restores the reserved bandwidth by adding back to\navailable_cell_rate without holding the lock.\n\nThis introduces a race condition because available_cell_rate is a global\ndevice resource shared across all VCCs. If the error path in\nfore200e_open() executes concurrently with operations like\nfore200e_close() or fore200e_change_qos() on other VCCs, a\nread-modify-write race occurs.\n\nSpecifically, the error path reads the rate without the lock. If another\nCPU acquires the lock and modifies the rate (e.g., releasing bandwidth in\nfore200e_close()) between this read and the subsequent write, the error\npath will overwrite the concurrent update with a stale value. This results\nin incorrect bandwidth accounting."
},
{
"lang": "es",
"value": "En el kernel de Linux, se ha corregido la siguiente vulnerabilidad:\\n\\natm/fore200e: Corrige una posible condición de carrera de datos en fore200e_open()\\n\\nProtege el acceso a fore200e -> available_cell_rate con el bloqueo rate_mtx en la ruta de manejo de errores de fore200e_open() para evitar una condición de carrera de datos.\\n\\nEl campo fore200e -> available_cell_rate es un recurso compartido utilizado para rastrear el ancho de banda disponible. Es accedido concurrentemente por fore200e_open(), fore200e_close() y fore200e_change_qos().\\n\\nEn fore200e_open(), el bloqueo rate_mtx se mantiene correctamente al restar vcc -> qos.txtp.max_pcr de available_cell_rate para reservar ancho de banda. Sin embargo, si la llamada posterior a fore200e_activate_vcin() falla, la función restaura el ancho de banda reservado añadiendo de nuevo a available_cell_rate sin mantener el bloqueo.\\n\\nEsto introduce una condición de carrera porque available_cell_rate es un recurso global del dispositivo compartido entre todos los VCC. Si la ruta de error en fore200e_open() se ejecuta concurrentemente con operaciones como fore200e_close() o fore200e_change_qos() en otros VCC, se produce una condición de carrera de lectura-modificación-escritura.\\n\\nEspecíficamente, la ruta de error lee la tasa sin el bloqueo. Si otra CPU adquiere el bloqueo y modifica la tasa (por ejemplo, liberando ancho de banda en fore200e_close()) entre esta lectura y la escritura posterior, la ruta de error sobrescribirá la actualización concurrente con un valor obsoleto. Esto resulta en una contabilidad de ancho de banda incorrecta."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"drivers/atm/fore200e.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
"lessThan": "1b60f42a639999c37da7f1fbfa1ad29cf4cbdd2d",
"versionType": "git",
"status": "affected"
},
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"status": "affected"
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{
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{
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"lessThan": "9917ba597cf95f307778e495f71ff25a5064d167",
"versionType": "git",
"status": "affected"
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{
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"lessThan": "667ac868823224374f819500adc5baa2889c7bc5",
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},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"drivers/atm/fore200e.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "2.6.12",
"status": "affected"
},
{
"version": "0",
"lessThan": "2.6.12",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.247",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.197",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.159",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.119",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.61",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.17.11",
"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/1b60f42a639999c37da7f1fbfa1ad29cf4cbdd2d",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
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