CVE-2024-36479

2024-06-2414:15:12

416baaa9-dc9f-4396-8d5f-8c081fb06d67

web.nvd.nist.gov

linux

kernel

fpga

bridge

vulnerability

fixed

module

refcount

owner

pointer

dereference

driver

parent

device

null

registration

compatibility

documentation

interface

code clarity

6.7 Medium

AI Score

Confidence

High

0.0004 Low

EPSS

Percentile

15.7%

JSON

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

fpga: bridge: add owner module and take its refcount

The current implementation of the fpga bridge assumes that the low-level
module registers a driver for the parent device and uses its owner pointer
to take the module’s refcount. This approach is problematic since it can
lead to a null pointer dereference while attempting to get the bridge if
the parent device does not have a driver.

To address this problem, add a module owner pointer to the fpga_bridge
struct and use it to take the module’s refcount. Modify the function for
registering a bridge to take an additional owner module parameter and
rename it to avoid conflicts. Use the old function name for a helper macro
that automatically sets the module that registers the bridge as the owner.
This ensures compatibility with existing low-level control modules and
reduces the chances of registering a bridge without setting the owner.

Also, update the documentation to keep it consistent with the new interface
for registering an fpga bridge.

Other changes: opportunistically move put_device() from __fpga_bridge_get()
to fpga_bridge_get() and of_fpga_bridge_get() to improve code clarity since
the bridge device is taken in these functions.

Affected configurations

Vulners

Node

linuxlinux_kernelRange4.10–6.6.33

linuxlinux_kernelRange6.7.0–6.9.4

linuxlinux_kernelRange6.10.0–6.10-rc1

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "Documentation/driver-api/fpga/fpga-bridge.rst",
      "drivers/fpga/fpga-bridge.c",
      "include/linux/fpga/fpga-bridge.h"
    ],
    "versions": [
      {
        "version": "21aeda950c5f",
        "lessThan": "d7c4081c54a1",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "21aeda950c5f",
        "lessThan": "6896b6b2e2d9",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "21aeda950c5f",
        "lessThan": "1da11f822042",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "Documentation/driver-api/fpga/fpga-bridge.rst",
      "drivers/fpga/fpga-bridge.c",
      "include/linux/fpga/fpga-bridge.h"
    ],
    "versions": [
      {
        "version": "4.10",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "4.10",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.6.33",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.9.4",
        "lessThanOrEqual": "6.9.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.10-rc1",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]