CVE-2026-43313 ACPI: processor: Fix NULL-pointer dereference in acpi_processor_errata_piix4()
A NULL pointer dereference in the Linux kernel ACPI processor driver can cause a system crash, requiring a kernel patch to fix.
- 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
What is CVE-2026-43313?
CVE-2026-43313 is a medium-severity vulnerability in Linux kernel, published on 8 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:
ACPI: processor: Fix NULL-pointer dereference in acpi_processor_errata_piix4()
In acpi_processor_errata_piix4(), the pointer dev is first assigned an IDE device and then reassigned an ISA device:
dev = pci_get_subsys(..., PCI_DEVICE_ID_INTEL_82371AB, ...); dev = pci_get_subsys(..., PCI_DEVICE_ID_INTEL_82371AB_0, ...);
If the first lookup succeeds but the second fails, dev becomes NULL. This leads to a potential null-pointer dereference when dev_dbg() is called:
if (errata.piix4.bmisx) dev_dbg(&dev->dev, ...);
To prevent this, use two temporary pointers and retrieve each device independently, avoiding overwriting dev with a possible NULL value.
[ rjw: Subject adjustment, added an empty code line ]
Weakness: CWE-476
Which versions are affected by CVE-2026-43313?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-43313?
Apply the vendor's patch.
Is CVE-2026-43313 being exploited?
There is no known exploitation of CVE-2026-43313 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-43313, DEBIAN-CVE-2026-43313, GHSA-px47-fmm9-rxw4, ROOT-OS-DEBIAN-11-CVE-2026-43313, ROOT-OS-UBUNTU-2204-CVE-2026-43313, ROOT-OS-UBUNTU-2404-CVE-2026-43313 and 1 more.