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Review reviewHigh

CVE-2025-39986

Linux

In the Linux kernel, the following vulnerability has been resolved: can: sun4i_can: 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 sun4i_can 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...

CVSS
7.8
EPSS
0.16%
5.76% percentile
CISA KEV
Not listed
Published
2025.10.15
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.16%
Technical severityCVSS 7.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: can: sun4i_can: 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 sun4i_can 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...

Affected product and versions

Product
Linux
Affected versions
>= 0738eff14d817a02ab082c392c96a1613006f158 < 063539db42203b29d5aa2adf0cae3d68c646a6b6, >= 0738eff14d817a02ab082c392c96a1613006f158 < 4f382cc887adca8478b9d3e6b81aa6698a95fff4, >= 0738eff14d817a02ab082c392c96a1613006f158 < 60463a1c138900494cb3adae41142a11cd8feb3c, >= 0738eff14d817a02ab082c392c96a1613006f158 < a61ff7ac93270d20ca426c027d6d01c8ac8e904c, >= 0738eff14d817a02ab082c392c96a1613006f158 < 2e423e1990f3972cbea779883fef52c2f2acb858, >= 0738eff14d817a02ab082c392c96a1613006f158 < de77841652e57afbc46e9e1dbf51ee364fc008e1, >= 0738eff14d817a02ab082c392c96a1613006f158 < 7f7b21026a6febdb749f6f6f950427245aa86cce, >= 0738eff14d817a02ab082c392c96a1613006f158 < 61da0bd4102c459823fbe6b8b43b01fb6ace4a22, >= 4.4
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
Not available