Bug 2525493 (CVE-2026-80651)

Summary: CVE-2026-80651 kernel: crypto: ccp/sev-dev-tsm - bail out early when pdev->bus is NULL
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's `crypto: ccp/sev-dev-tsm` module. The `dsm_create()` function fails to properly validate the `pdev->bus` pointer, leading to a null pointer dereference. A local attacker could exploit this vulnerability to trigger a kernel crash, resulting in a Denial of Service (DoS).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-08-28 07:47:49 UTC
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.