usb: cdc-acm: Check control transfer buffer size before access 漏洞信息(CVE-2025-21704)

一、漏洞 CVE-2025-21704 基础信息

AIGC 神龙大模型
美国国家漏洞数据库 NVD

漏洞标题

USB: CDC-ACM: 在访问控制传输缓冲区之前检查其大小

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漏洞描述信息

在Linux内核中，已解决了以下漏洞： usb: cdc-acm: 在访问之前检查控制传输缓冲区大小如果第一个片段比struct usb_cdc_notification短，我们无法计算expected_size。记录错误并丢弃通知，而不是从接收到的数据之外的内存中读取长度。这可能导致内存损坏，特别是在fragments之间expected_size减少的情况下，导致`expected_size - acm->nb_index`溢出。此问题自git历史记录开始就存在；然而，只有在提交ea2583529cd1（"cdc-acm: reassemble fragmented notifications"）之后才会导致内存损坏。缓解因素是acm_ctrl_irq()只能在用户空间打开/dev/ttyACM*后执行；但如果ModemManager正在运行，它会根据USB设备的厂商/产品ID及其其他接口自动执行该操作。

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CVSS信息

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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漏洞类别

跨界内存写

来源：AIGC 神龙大模型

漏洞标题

usb: cdc-acm: Check control transfer buffer size before access

来源：美国国家漏洞数据库 NVD

漏洞描述信息

In the Linux kernel, the following vulnerability has been resolved: usb: cdc-acm: Check control transfer buffer size before access If the first fragment is shorter than struct usb_cdc_notification, we can't calculate an expected_size. Log an error and discard the notification instead of reading lengths from memory outside the received data, which can lead to memory corruption when the expected_size decreases between fragments, causing `expected_size - acm->nb_index` to wrap. This issue has been present since the beginning of git history; however, it only leads to memory corruption since commit ea2583529cd1 ("cdc-acm: reassemble fragmented notifications"). A mitigating factor is that acm_ctrl_irq() can only execute after userspace has opened /dev/ttyACM*; but if ModemManager is running, ModemManager will do that automatically depending on the USB device's vendor/product IDs and its other interfaces.

来源：美国国家漏洞数据库 NVD

CVSS信息

N/A

来源：美国国家漏洞数据库 NVD

漏洞类别

N/A

来源：美国国家漏洞数据库 NVD

二、漏洞 CVE-2025-21704 的公开POC

#	POC 描述	源链接	神龙链接

三、漏洞 CVE-2025-21704 的情报信息

标题： usb: cdc-acm: Check control transfer buffer size before access - kernel/git/stable/linux.git - Linux kernel stable tree -- 🔗来源链接

标签：
标题： usb: cdc-acm: Check control transfer buffer size before access - kernel/git/stable/linux.git - Linux kernel stable tree -- 🔗来源链接

标签：
标题： usb: cdc-acm: Check control transfer buffer size before access - kernel/git/stable/linux.git - Linux kernel stable tree -- 🔗来源链接

标签：
标题： usb: cdc-acm: Check control transfer buffer size before access - kernel/git/stable/linux.git - Linux kernel stable tree -- 🔗来源链接

标签：
标题： usb: cdc-acm: Check control transfer buffer size before access - kernel/git/stable/linux.git - Linux kernel stable tree -- 🔗来源链接

标签：
https://nvd.nist.gov/vuln/detail/CVE-2025-21704