CVE-2026-80651 crypto: ccp/sev-dev-tsm - bail out early when pdev->bus is NULL
A null pointer dereference in the Linux kernel's SEV TSM driver allows local attackers to cause a system crash.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-80651?
CVE-2026-80651 is a vulnerability in Linux, published on 28 Aug 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:
crypto: ccp/sev-dev-tsm - bail out early when pdev->bus is NULL
dsm_create() initially checks pdev->bus when computing segment_id:
u8 segment_id = pdev->bus ? pci_domain_nr(pdev->bus) : 0;
But the next two lines unconditionally dereference pdev->bus via pcie_find_root_port() and especially pci_dev_id(pdev), which expands to PCI_DEVID(dev->bus->number, dev->devfn). If pdev->bus is in fact NULL, segment_id is initialised to 0 but the very next statement crashes the kernel.
smatch flags this:
drivers/crypto/ccp/sev-dev-tsm.c:253 dsm_create() error: we previously assumed 'pdev->bus' could be null (see line 251)
Make the NULL handling consistent: if pdev->bus is NULL the device has no PCI context to work with and SEV TIO setup cannot proceed, so return -ENODEV before any of the bus-dependent lookups. The remaining initialisation now runs only on the path where pdev->bus is known to be valid.
No change for callers where pdev->bus is non-NULL, which is the only case where dsm_create() did meaningful work before this change.
Which versions are affected by CVE-2026-80651?
How do I fix CVE-2026-80651?
Apply the vendor's patch.
Is CVE-2026-80651 being exploited?
There is no known exploitation of CVE-2026-80651 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-80651, GHSA-m48c-q8rx-qxxm, UBUNTU-CVE-2026-80651.