Linux Kernel up to 6.16.7 dev_ioctl privilege escalation

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.16.7. It has been rated as critical. The impacted element is the function dev_ioctl. Performing a manipulation results in an unknown weakness. This vulnerability is reported as CVE-2025-39908. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.16.7. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: net: dev_ioctl: take ops lock in hwtstamp lower paths ndo hwtstamp callbacks are expected to run under the per-device ops lock. Make the lower get/set paths consistent with the rest of ndo invocations. Kernel log: WARNING: CPU: 13 PID: 51364 at ./include/net/netdev_lock.h:70 __netdev_update_features+0x4bd/0xe60 ... RIP: 0010:__netdev_update_features+0x4bd/0xe60 ... Call Trace: <TASK> netdev_update_features+0x1f/0x60 mlx5_hwtstamp_set+0x181/0x290 [mlx5_core] mlx5e_hwtstamp_set+0x19/0x30 [mlx5_core] dev_set_hwtstamp_phylib+0x9f/0x220 dev_set_hwtstamp_phylib+0x9f/0x220 dev_set_hwtstamp+0x13d/0x240 dev_ioctl+0x12f/0x4b0 sock_ioctl+0x171/0x370 __x64_sys_ioctl+0x3f7/0x900 ? __sys_setsockopt+0x69/0xb0 do_syscall_64+0x6f/0x2e0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 ... </TASK> .... ---[ end trace 0000000000000000 ]--- Note that the mlx5_hwtstamp_set and mlx5e_hwtstamp_set functions shown in the trace come from an in progress patch converting the legacy ioctl to ndo_hwtstamp_get/set and are not present in mainline.

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2025-39908 since 04/16/2025. The exploitability is told to be difficult. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 269683 (Linux Distros Unpatched Vulnerability : CVE-2025-39908), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.16.8 eliminates this vulnerability. Applying the patch 2d92fa0cdc02291de57f72170e8b60cef0cf5372/686cab5a18e443e1d5f2abb17bed45837836425f is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (269683), EUVD (EUVD-2025-32872) and CERT Bund (WID-SEC-2025-2170). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• RESF Rocky Linux
• Open Source Linux Kernel
• Dell Secure Connect Gateway

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.16.0
• 6.16.1
• 6.16.2
• 6.16.3
• 6.16.4
• 6.16.5
• 6.16.6
• 6.16.7

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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