# CVE-2026-43015: net: macb: fix clk handling on PCI glue driver removal

> A use-after-free vulnerability in the Linux kernel macb PCI driver allows local attackers to cause a system crash or potentially execute code during driver removal.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 May 2026
- **Updated:** 23 May 2026
- **Also known as:** BELL-CVE-2026-43015, DEBIAN-CVE-2026-43015, GHSA-x83c-972p-8775, ROOT-OS-DEBIAN-11-CVE-2026-43015, ROOT-OS-UBUNTU-2204-CVE-2026-43015, ROOT-OS-UBUNTU-2404-CVE-2026-43015, UBUNTU-CVE-2026-43015

## What is CVE-2026-43015?

CVE-2026-43015 is a high-severity use after free vulnerability in Linux kernel, published on 1 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

net: macb: fix clk handling on PCI glue driver removal

platform_device_unregister() may still want to use the registered clks
during runtime resume callback.

Note that there is a commit d82d5303c4c5 ("net: macb: fix use after free
on rmmod") that addressed the similar problem of clk vs platform device
unregistration but just moved the bug to another place.

Save the pointers to clks into local variables for reuse after platform
device is unregistered.

BUG: KASAN: use-after-free in clk_prepare+0x5a/0x60
Read of size 8 at addr ffff888104f85e00 by task modprobe/597

CPU: 2 PID: 597 Comm: modprobe Not tainted 6.1.164+ #114
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.1-0-g3208b098f51a-prebuilt.qemu.org 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x8d/0xba
 print_report+0x17f/0x496
 kasan_report+0xd9/0x180
 clk_prepare+0x5a/0x60
 macb_runtime_resume+0x13d/0x410 [macb]
 pm_generic_runtime_resume+0x97/0xd0
 __rpm_callback+0xc8/0x4d0
 rpm_callback+0xf6/0x230
 rpm_resume+0xeeb/0x1a70
 __pm_runtime_resume+0xb4/0x170
 bus_remove_device+0x2e3/0x4b0
 device_del+0x5b3/0xdc0
 platform_device_del+0x4e/0x280
 platform_device_unregister+0x11/0x50
 pci_device_remove+0xae/0x210
 device_remove+0xcb/0x180
 device_release_driver_internal+0x529/0x770
 driver_detach+0xd4/0x1a0
 bus_remove_driver+0x135/0x260
 driver_unregister+0x72/0xb0
 pci_unregister_driver+0x26/0x220
 __do_sys_delete_module+0x32e/0x550
 do_syscall_64+0x35/0x80
 entry_SYSCALL_64_after_hwframe+0x6e/0xd8
 </TASK>

Allocated by task 519:
 kasan_save_stack+0x2c/0x50
 kasan_set_track+0x21/0x30
 __kasan_kmalloc+0x8e/0x90
 __clk_register+0x458/0x2890
 clk_hw_register+0x1a/0x60
 __clk_hw_register_fixed_rate+0x255/0x410
 clk_register_fixed_rate+0x3c/0xa0
 macb_probe+0x1d8/0x42e [macb_pci]
 local_pci_probe+0xd7/0x190
 pci_device_probe+0x252/0x600
 really_probe+0x255/0x7f0
 __driver_probe_device+0x1ee/0x330
 driver_probe_device+0x4c/0x1f0
 __driver_attach+0x1df/0x4e0
 bus_for_each_dev+0x15d/0x1f0
 bus_add_driver+0x486/0x5e0
 driver_register+0x23a/0x3d0
 do_one_initcall+0xfd/0x4d0
 do_init_module+0x18b/0x5a0
 load_module+0x5663/0x7950
 __do_sys_finit_module+0x101/0x180
 do_syscall_64+0x35/0x80
 entry_SYSCALL_64_after_hwframe+0x6e/0xd8

Freed by task 597:
 kasan_save_stack+0x2c/0x50
 kasan_set_track+0x21/0x30
 kasan_save_free_info+0x2a/0x50
 __kasan_slab_free+0x106/0x180
 __kmem_cache_free+0xbc/0x320
 clk_unregister+0x6de/0x8d0
 macb_remove+0x73/0xc0 [macb_pci]
 pci_device_remove+0xae/0x210
 device_remove+0xcb/0x180
 device_release_driver_internal+0x529/0x770
 driver_detach+0xd4/0x1a0
 bus_remove_driver+0x135/0x260
 driver_unregister+0x72/0xb0
 pci_unregister_driver+0x26/0x220
 __do_sys_delete_module+0x32e/0x550
 do_syscall_64+0x35/0x80
 entry_SYSCALL_64_after_hwframe+0x6e/0xd8

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2026-43015?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-43015?

Apply the vendor's patch.

## Is CVE-2026-43015 being exploited?

There is no known exploitation of CVE-2026-43015 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-43015 and fix it if it is affected.

What it is: CVE-2026-43015 is a high-severity use after free vulnerability in Linux kernel, published on 1 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-43015 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-43015/ (Markdown: https://insights.sbomify.com/CVE-2026-43015/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-43015
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-43015
- OSV: https://osv.dev/vulnerability/CVE-2026-43015

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-43015/
Summaries are generated and may contain mistakes; the official description above is the record.