In the Linux kernel, the following vulnerability has been resolved:

net: phy: clear phydev->devlink when the link is deleted

There is a potential crash issue when disabling and re-enabling the
network port. When disabling the network port, phy_detach() calls
device_link_del() to remove the device link, but it does not clear
phydev->devlink, so phydev->devlink is not a NULL pointer. Then the
network port is re-enabled, but if phy_attach_direct() fails before
calling device_link_add(), the code jumps to the "error" label and
calls phy_detach(). Since phydev->devlink retains the old value from
the previous attach/detach cycle, device_link_del() uses the old value,
which accesses a NULL pointer and causes a crash. The simplified crash
log is as follows.

[ 24.702421] Call trace:
[ 24.704856] device_link_put_kref+0x20/0x120
[ 24.709124] device_link_del+0x30/0x48
[ 24.712864] phy_detach+0x24/0x168
[ 24.716261] phy_attach_direct+0x168/0x3a4
[ 24.720352] phylink_fwnode_phy_connect+0xc8/0x14c
[ 24.725140] phylink_of_phy_connect+0x1c/0x34

Therefore, phydev->devlink needs to be cleared when the device link is
deleted.
Advisories
Source ID Title
EUVD EUVD EUVD-2025-19794 In the Linux kernel, the following vulnerability has been resolved: net: phy: clear phydev->devlink when the link is deleted There is a potential crash issue when disabling and re-enabling the network port. When disabling the network port, phy_detach() calls device_link_del() to remove the device link, but it does not clear phydev->devlink, so phydev->devlink is not a NULL pointer. Then the network port is re-enabled, but if phy_attach_direct() fails before calling device_link_add(), the code jumps to the "error" label and calls phy_detach(). Since phydev->devlink retains the old value from the previous attach/detach cycle, device_link_del() uses the old value, which accesses a NULL pointer and causes a crash. The simplified crash log is as follows. [ 24.702421] Call trace: [ 24.704856] device_link_put_kref+0x20/0x120 [ 24.709124] device_link_del+0x30/0x48 [ 24.712864] phy_detach+0x24/0x168 [ 24.716261] phy_attach_direct+0x168/0x3a4 [ 24.720352] phylink_fwnode_phy_connect+0xc8/0x14c [ 24.725140] phylink_of_phy_connect+0x1c/0x34 Therefore, phydev->devlink needs to be cleared when the device link is deleted.
Ubuntu USN Ubuntu USN USN-7769-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7769-2 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7769-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7770-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7771-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-7789-1 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-7789-2 Linux kernel (Raspberry Pi) vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Thu, 20 Nov 2025 20:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-476
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Metrics cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}


Fri, 04 Jul 2025 00:30:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate


Thu, 03 Jul 2025 09:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: net: phy: clear phydev->devlink when the link is deleted There is a potential crash issue when disabling and re-enabling the network port. When disabling the network port, phy_detach() calls device_link_del() to remove the device link, but it does not clear phydev->devlink, so phydev->devlink is not a NULL pointer. Then the network port is re-enabled, but if phy_attach_direct() fails before calling device_link_add(), the code jumps to the "error" label and calls phy_detach(). Since phydev->devlink retains the old value from the previous attach/detach cycle, device_link_del() uses the old value, which accesses a NULL pointer and causes a crash. The simplified crash log is as follows. [ 24.702421] Call trace: [ 24.704856] device_link_put_kref+0x20/0x120 [ 24.709124] device_link_del+0x30/0x48 [ 24.712864] phy_detach+0x24/0x168 [ 24.716261] phy_attach_direct+0x168/0x3a4 [ 24.720352] phylink_fwnode_phy_connect+0xc8/0x14c [ 24.725140] phylink_of_phy_connect+0x1c/0x34 Therefore, phydev->devlink needs to be cleared when the device link is deleted.
Title net: phy: clear phydev->devlink when the link is deleted
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-07-28T04:13:37.893Z

Reserved: 2025-04-16T04:51:23.988Z

Link: CVE-2025-38149

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2025-07-03T09:15:29.830

Modified: 2025-11-20T20:09:32.800

Link: CVE-2025-38149

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-07-03T00:00:00Z

Links: CVE-2025-38149 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2025-07-06T22:16:22Z