Linux Kernel up to 6.12.44/6.16.4/6.17-rc3 Netdev Call fs/kernfs/dir.c macb_remove privilege escalation

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CTI Interest Score
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4.9$0-$5k0.00

Summaryinfo

A vulnerability identified as critical has been detected in Linux Kernel up to 6.12.44/6.16.4/6.17-rc3. Impacted is the function macb_remove of the file fs/kernfs/dir.c of the component Netdev Call Handler. Performing a manipulation results in an unknown weakness. This vulnerability is reported as CVE-2025-39805. No exploit exists. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.12.44/6.16.4/6.17-rc3. This affects the function macb_remove of the file fs/kernfs/dir.c of the component Netdev Call Handler. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: net: macb: fix unregister_netdev call order in macb_remove() When removing a macb device, the driver calls phy_exit() before unregister_netdev(). This leads to a WARN from kernfs: ------------[ cut here ]------------ kernfs: can not remove 'attached_dev', no directory WARNING: CPU: 1 PID: 27146 at fs/kernfs/dir.c:1683 Call trace: kernfs_remove_by_name_ns+0xd8/0xf0 sysfs_remove_link+0x24/0x58 phy_detach+0x5c/0x168 phy_disconnect+0x4c/0x70 phylink_disconnect_phy+0x6c/0xc0 [phylink] macb_close+0x6c/0x170 [macb] ... macb_remove+0x60/0x168 [macb] platform_remove+0x5c/0x80 ... The warning happens because the PHY is being exited while the netdev is still registered. The correct order is to unregister the netdev before shutting down the PHY and cleaning up the MDIO bus. Fix this by moving unregister_netdev() ahead of phy_exit() in macb_remove().

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2025-39805 since 04/16/2025. The exploitability is told to be difficult. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 265291 (Linux Distros Unpatched Vulnerability : CVE-2025-39805), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.12.45, 6.16.5 or 6.17-rc4 eliminates this vulnerability. Applying the patch ff0d3bad32108b57265e5b48f15327549af771d3/775fe690fd4a3337ad2115de2adb41b227d4dae7/01b9128c5db1b470575d07b05b67ffa3cb02ebf1 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 (265291), EUVD (EUVD-2025-29609) and CERT Bund (WID-SEC-2025-2077). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

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

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.0
VulDB Meta Temp Score: 4.9

VulDB Base Score: 4.6
VulDB Temp Score: 4.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Privilege escalation
CWE: Unknown
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 265291
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2025-39805

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.45/6.16.5/6.17-rc4
Patch: ff0d3bad32108b57265e5b48f15327549af771d3/775fe690fd4a3337ad2115de2adb41b227d4dae7/01b9128c5db1b470575d07b05b67ffa3cb02ebf1

Timelineinfo

04/16/2025 CVE reserved
09/16/2025 +153 days Advisory disclosed
09/16/2025 +0 days VulDB entry created
12/27/2025 +102 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-39805 (🔒)
GCVE (CVE): GCVE-0-2025-39805
GCVE (VulDB): GCVE-100-324417
EUVD: 🔒
CERT Bund: WID-SEC-2025-2077 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 09/16/2025 15:59
Updated: 12/27/2025 13:13
Changes: 09/16/2025 15:59 (59), 09/18/2025 15:09 (2), 10/21/2025 06:25 (7), 12/03/2025 04:12 (11), 12/07/2025 01:12 (1), 12/27/2025 13:13 (1)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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