CVE-2021-47416 phy: mdio: fix memory leak

2024-05-2115:04:06

Linux

www.cve.org

linux kernel

vulnerability resolved

memory leak fix

phy

mdio

state logic

bus interface

device register.

AI Score

6.4

Confidence

High

EPSS

Percentile

13.0%

JSON

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

phy: mdio: fix memory leak

Syzbot reported memory leak in MDIO bus interface, the problem was in
wrong state logic.

MDIOBUS_ALLOCATED indicates 2 states:
1. Bus is only allocated
2. Bus allocated and __mdiobus_register() fails, but
device_register() was called

In case of device_register() has been called we should call put_device()
to correctly free the memory allocated for this device, but mdiobus_free()
calls just kfree(dev) in case of MDIOBUS_ALLOCATED state

To avoid this behaviour we need to set bus->state to MDIOBUS_UNREGISTERED
before calling device_register(), because put_device() should be
called even in case of device_register() failure.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/net/phy/mdio_bus.c"
    ],
    "versions": [
      {
        "version": "46abc02175b3",
        "lessThan": "25e9f88c7e3c",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "46abc02175b3",
        "lessThan": "2250392d930b",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "46abc02175b3",
        "lessThan": "f4f502a04ee1",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "46abc02175b3",
        "lessThan": "2397b9e11872",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "46abc02175b3",
        "lessThan": "414bb4ead136",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "46abc02175b3",
        "lessThan": "0d2dd40a7be6",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "46abc02175b3",
        "lessThan": "064c2616234a",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "46abc02175b3",
        "lessThan": "ca6e11c337da",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/net/phy/mdio_bus.c"
    ],
    "versions": [
      {
        "version": "2.6.28",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "2.6.28",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.4.289",
        "lessThanOrEqual": "4.4.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.9.287",
        "lessThanOrEqual": "4.9.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.14.251",
        "lessThanOrEqual": "4.14.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.19.211",
        "lessThanOrEqual": "4.19.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.4.153",
        "lessThanOrEqual": "5.4.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.73",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.14.12",
        "lessThanOrEqual": "5.14.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.15",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]