⚠ Reference material — not professional advice. Test in staging, back up first, verify against your specific version. Use your own judgment for your environment.
● Not verified

How to Fix CVE-2026-43015: net: macb: fix clk handling on PCI glue driver removal in Linux

By Sai Kiran Pandrala

Other vulnerabilities in the same area that are worth patching alongside this one:

Last verified: 2026-05-25

CVE-2026-43015 is a net: macb: fix clk handling on pci glue driver removal in Linux Linux. Fix it by upgrading to 5.10.253, 5.15.203, 6.1.168, 6.6.134, 6.12.81, 6.18.22.

⚡ At a glance
SeverityNot verified - see official advisory
Actively exploited?Not currently in the CISA KEV catalog
AffectedLinux 7721221e87d25c9840d9ca6b986dbdc410d5ce2b up to (excluding) bf64cae913cdd4821f13d5d1d68900c0891bef69; Linux d82d5303c4c539db86588ffb5dc5b26c3f1513e8 up to (excluding) 67f70841a175fa3469119f52d77a3662c07507a2; Linux d82d5303c4c539db86588ffb5dc5b26c3f1513e8 up to (excluding) 2d96204e4184d6f7dd2f93c6f218fd0c1f55e9ae; Linux d82d5303c4c539db86588ffb5dc5b26c3f1513e8 up to (excluding) b3f799cdf830df1782ae463cf15ace35015be99e; Linux d82d5303c4c539db86588ffb5dc5b26c3f1513e8 up to (excluding) f310a836da90d0f0321b14d446c071af63f9ee4c; Linux d82d5303c4c539db86588ffb5dc5b26c3f1513e8 up to (excluding) 16ab4c0e2b15df5d33bfcb9ea8e4441b85dd4a57
Fixed in5.10.253, 5.15.203, 6.1.168, 6.6.134, 6.12.81, 6.18.22
Type (CWE)Not verified

What is CVE-2026-43015?

CVE-2026-43015 is a net: macb: fix clk handling on pci glue driver removal flaw in Linux Linux. The vendor has not published a verified CVSS metric at the time of writing. It is not currently listed in the CISA Known Exploited Vulnerabilities catalog.

From the source record: 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.

Why it matters in practice: The blast radius depends on how the affected service is exposed. An internet-facing instance with no compensating controls is the highest-risk configuration.

Am I affected?

You are affected if your installation of Linux matches a version listed in the Affected row above.


# Debian/Ubuntu
dpkg -s linux | grep Version
# RHEL/Rocky
rpm -q linux

How to fix CVE-2026-43015

Apply the vendor patch. Target the build named in the Fixed in row above (5.10.253, 5.15.203, 6.1.168, 6.6.134, 6.12.81, 6.18.22). The runnable command set below covers the most common deployment patterns for Linux.

Ubuntu / Debian


sudo apt-get update
sudo apt-get install --only-upgrade linux
dpkg -s linux | grep Version

RHEL / CentOS / Rocky


sudo dnf upgrade linux -y
rpm -q linux

After applying the patch

  1. Restart the service or device so the patched binary loads.
  2. Confirm the running version matches the Fixed in row using the verification command below.
  3. Rotate credentials and API keys that the affected service could access if the asset was exposed during the disclosure window.

If you can't patch immediately

Until the patch lands, narrow the attack surface with these runnable controls.

Restrict network exposure

Block public access to the affected service at the perimeter. Allow only trusted source IPs.


# Linux iptables: only allow trusted admin subnet
sudo iptables -A INPUT -p tcp --dport 443 -s 10.10.10.0/24 -j ACCEPT
sudo iptables -A INPUT -p tcp --dport 443 -j DROP
sudo iptables-save | sudo tee /etc/iptables/rules.v4


# Windows firewall: only allow trusted admin subnet on management port
New-NetFirewallRule -DisplayName "Restrict-Mgmt-Allow" -Direction Inbound -Action Allow `
  -RemoteAddress 10.10.10.0/24 -Protocol TCP -LocalPort 443
New-NetFirewallRule -DisplayName "Restrict-Mgmt-Deny"  -Direction Inbound -Action Block `
  -Protocol TCP -LocalPort 443

Mitigations are temporary. Apply the vendor patch as soon as a maintenance window opens.

How to verify the fix worked

Confirm the patched build is the one actually running.


# Debian/Ubuntu
dpkg -s linux | grep Version
# RHEL/Rocky
rpm -q linux

Expected: a version at or above 5.10.253, 5.15.203, 6.1.168, 6.6.134, 6.12.81, 6.18.22.

Also worth doing: pull recent log windows for indicators of compromise listed in the vendor advisory, and re-run an authenticated vulnerability scan with up-to-date signatures.

Frequently asked questions

Is CVE-2026-43015 being exploited in the wild?

As of 2026-05-25, CVE-2026-43015 is not listed in the CISA Known Exploited Vulnerabilities catalog. Watch the catalog and patch on a normal cadence; KEV status can change as exploitation evidence emerges.

What is the CVSS score for CVE-2026-43015?

A verified CVSS score is not listed in the public record for CVE-2026-43015. Check the vendor advisory and the NVD page for an updated metric.

What version fixes this?

Upgrade to 5.10.253, 5.15.203, 6.1.168, 6.6.134, 6.12.81, 6.18.22.

Will a WAF or IDS rule alone close this?

No. Network filters cut down opportunistic scans but they do not remove the flaw. The vendor patch is the only durable fix.

References

*Assembled from the official vendor advisory, the NVD record, and the CISA KEV listing on 2026-05-25. Always confirm against the vendor advisory before applying changes in production.*