NULL Pointer Dereference Affecting kernel-modules-extra-common package, versions <0:6.12.35-55.103.amzn2023


Severity

Recommended
0.0
high
0
10

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.01% (1st percentile)

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  • Snyk IDSNYK-AMZN2023-KERNELMODULESEXTRACOMMON-11481363
  • published5 Aug 2025
  • disclosed3 Jul 2025

Introduced: 3 Jul 2025

CVE-2025-38149  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 kernel-modules-extra-common to version 0:6.12.35-55.103.amzn2023 or higher.
This issue was patched in ALAS2023-2025-1080.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-modules-extra-common package and not the kernel-modules-extra-common package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1