CVE-2025-39988
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: can: etas_es58x: populate ndo_change_mtu() to prevent buffer overflow Sending an PF_PACKET allows to bypass the CAN framework logic and to directly reach the xmit() function of a CAN driver. The only check which is performed by the PF_PACKET framework is to make sure that skb->len fits the interface's MTU. Unfortunately, because the etas_es58x driver does not populate its net_device_ops->ndo_change_mtu(), it is possible for an attacker to configure an invalid MTU by doing, for example: $ ip link set can0 mtu 9999 After doing so, the attacker could open a PF_PACKET socket using the ETH_P_CANXL protocol: socket(PF_PACKET, SOCK_RAW, htons(ETH_P_CANXL)); to inject a malicious CAN XL frames. For example: struct canxl_frame frame = { .flags = 0xff, .len = 2048, }; The CAN drivers' xmit() function are calling can_dev_dropped_skb() to check that the skb is valid, unfortunately under above conditions, the malicious packet is able to go through can_dev_dropped_skb() checks: 1. the skb->protocol is set to ETH_P_CANXL which is valid (the function does not check the actual device capabilities). 2. the length is a valid CAN XL length. And so, es58x_start_xmit() receives a CAN XL frame which it is not able to correctly handle and will thus misinterpret it as a CAN(FD) frame. This can result in a buffer overflow. For example, using the es581.4 variant, the frame will be dispatched to es581_4_tx_can_msg(), go through the last check at the beginning of this function: if (can_is_canfd_skb(skb)) return -EMSGSIZE; and reach this line: memcpy(tx_can_msg->data, cf->data, cf->len); Here, cf->len corresponds to the flags field of the CAN XL frame. In our previous example, we set canxl_frame->flags to 0xff. Because the maximum expected length is 8, a buffer overflow of 247 bytes occurs! Populate net_device_ops->ndo_change_mtu() to ensure that the interface's MTU can not be set to anything bigger than CAN_MTU or CANFD_MTU (depending on the device capabilities). By fixing the root cause, this prevents the buffer overflow.
View original CVE JSON
{
"id": "CVE-2025-39988",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2025-10-15T08:15:36.913",
"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\ncan: etas_es58x: populate ndo_change_mtu() to prevent buffer overflow\n\nSending an PF_PACKET allows to bypass the CAN framework logic and to\ndirectly reach the xmit() function of a CAN driver. The only check\nwhich is performed by the PF_PACKET framework is to make sure that\nskb->len fits the interface's MTU.\n\nUnfortunately, because the etas_es58x driver does not populate its\nnet_device_ops->ndo_change_mtu(), it is possible for an attacker to\nconfigure an invalid MTU by doing, for example:\n\n $ ip link set can0 mtu 9999\n\nAfter doing so, the attacker could open a PF_PACKET socket using the\nETH_P_CANXL protocol:\n\n\tsocket(PF_PACKET, SOCK_RAW, htons(ETH_P_CANXL));\n\nto inject a malicious CAN XL frames. For example:\n\n\tstruct canxl_frame frame = {\n\t\t.flags = 0xff,\n\t\t.len = 2048,\n\t};\n\nThe CAN drivers' xmit() function are calling can_dev_dropped_skb() to\ncheck that the skb is valid, unfortunately under above conditions, the\nmalicious packet is able to go through can_dev_dropped_skb() checks:\n\n 1. the skb->protocol is set to ETH_P_CANXL which is valid (the\n function does not check the actual device capabilities).\n\n 2. the length is a valid CAN XL length.\n\nAnd so, es58x_start_xmit() receives a CAN XL frame which it is not\nable to correctly handle and will thus misinterpret it as a CAN(FD)\nframe.\n\nThis can result in a buffer overflow. For example, using the es581.4\nvariant, the frame will be dispatched to es581_4_tx_can_msg(), go\nthrough the last check at the beginning of this function:\n\n\tif (can_is_canfd_skb(skb))\n\t\treturn -EMSGSIZE;\n\nand reach this line:\n\n\tmemcpy(tx_can_msg->data, cf->data, cf->len);\n\nHere, cf->len corresponds to the flags field of the CAN XL frame. In\nour previous example, we set canxl_frame->flags to 0xff. Because the\nmaximum expected length is 8, a buffer overflow of 247 bytes occurs!\n\nPopulate net_device_ops->ndo_change_mtu() to ensure that the\ninterface's MTU can not be set to anything bigger than CAN_MTU or\nCANFD_MTU (depending on the device capabilities). By fixing the root\ncause, this prevents the buffer overflow."
},
{
"lang": "es",
"value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\ncan: etas_es58x: poblar ndo_change_mtu() para prevenir el desbordamiento de búfer\n\nEnviar un PF_PACKET permite eludir la lógica del framework CAN y alcanzar directamente la función xmit() de un controlador CAN. La única comprobación que realiza el framework PF_PACKET es asegurarse de que skb->len se ajusta a la MTU de la interfaz.\n\nDesafortunadamente, debido a que el controlador etas_es58x no puebla su net_device_ops->ndo_change_mtu(), es posible para un atacante configurar una MTU inválida haciendo, por ejemplo:\n\n $ ip link set can0 mtu 9999\n\nDespués de hacerlo, el atacante podría abrir un socket PF_PACKET usando el protocolo ETH_P_CANXL:\n\n\tsocket(PF_PACKET, SOCK_RAW, htons(ETH_P_CANXL));\n\npara inyectar tramas CAN XL maliciosas. Por ejemplo:\n\n\tstruct canxl_frame frame = {\n\t\t.flags = 0xff,\n\t\t.len = 2048,\n\t};\n\nLa función xmit() de los controladores CAN está llamando a can_dev_dropped_skb() para comprobar que el skb es válido, desafortunadamente bajo las condiciones anteriores, el paquete malicioso es capaz de pasar las comprobaciones de can_dev_dropped_skb():\n\n 1. el skb->protocol está configurado como ETH_P_CANXL, lo cual es válido (la función no comprueba las capacidades reales del dispositivo).\n\n 2. la longitud es una longitud CAN XL válida.\n\nY así, es58x_start_xmit() recibe una trama CAN XL que no es capaz de manejar correctamente y, por lo tanto, la malinterpretará como una trama CAN(FD).\n\nEsto puede resultar en un desbordamiento de búfer. Por ejemplo, usando la variante es581.4, la trama será despachada a es581_4_tx_can_msg(), pasando por la última comprobación al principio de esta función:\n\n\tif (can_is_canfd_skb(skb))\n\t\treturn -EMSGSIZE;\n\ny alcanzará esta línea:\n\n\tmemcpy(tx_can_msg->data, cf->data, cf->len);\n\nAquí, cf->len corresponde al campo de banderas de la trama CAN XL. En nuestro ejemplo anterior, establecimos canxl_frame->flags en 0xff. Debido a que la longitud máxima esperada es 8, ¡ocurre un desbordamiento de búfer de 247 bytes!\n\nPoblar net_device_ops->ndo_change_mtu() para asegurar que la MTU de la interfaz no pueda configurarse a nada mayor que CAN_MTU o CANFD_MTU (dependiendo de las capacidades del dispositivo). Al corregir la causa raíz, esto previene el desbordamiento de búfer."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"drivers/net/can/usb/etas_es58x/es58x_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "8537257874e949a59c834cecfd5a063e11b64b0b",
"lessThan": "72de0facc50afdb101fb7197d880407f1abfc77f",
"versionType": "git",
"status": "affected"
},
{
"version": "8537257874e949a59c834cecfd5a063e11b64b0b",
"lessThan": "c4e582e686c4d683c87f2b4a316385b3d81d370f",
"versionType": "git",
"status": "affected"
},
{
"version": "8537257874e949a59c834cecfd5a063e11b64b0b",
"lessThan": "cbc1de71766f326a44bb798aeae4a7ef4a081cc9",
"versionType": "git",
"status": "affected"
},
{
"version": "8537257874e949a59c834cecfd5a063e11b64b0b",
"lessThan": "b26cccd87dcddc47b450a40f3b1ac3fe346efcff",
"versionType": "git",
"status": "affected"
},
{
"version": "8537257874e949a59c834cecfd5a063e11b64b0b",
"lessThan": "e587af2c89ecc6382c518febea52fa9ba81e47c0",
"versionType": "git",
"status": "affected"
},
{
"version": "8537257874e949a59c834cecfd5a063e11b64b0b",
"lessThan": "38c0abad45b190a30d8284a37264d2127a6ec303",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"drivers/net/can/usb/etas_es58x/es58x_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "5.13",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.13",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.194",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.155",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.109",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.50",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.16.10",
"lessThanOrEqual": "6.16.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.17",
"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/38c0abad45b190a30d8284a37264d2127a6ec303",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/72de0facc50afdb101fb7197d880407f1abfc77f",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/b26cccd87dcddc47b450a40f3b1ac3fe346efcff",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
"url": "https://git.kernel.org/stable/c/c4e582e686c4d683c87f2b4a316385b3d81d370f",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
"url": "https://git.kernel.org/stable/c/cbc1de71766f326a44bb798aeae4a7ef4a081cc9",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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{
"url": "https://git.kernel.org/stable/c/e587af2c89ecc6382c518febea52fa9ba81e47c0",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}