A null pointer dereference occurs in the Linux kernel's crypto subsystem within the ccp/sev-dev-tsm driver. The dsm_create function assumes that pdev->bus is non‑NULL, but when it is NULL the function proceeds to dereference it unconditionally using pcie_find_root_port and pci_dev_id. This leads to a kernel crash, causing a denial of service. The flaw does not directly disclose data or alter system integrity; it mainly disrupts availability by forcing a kernel panic during cryptographic device initialization. Based on the description, it is a classic Null Pointer Dereference weakness (CWE-476).

Any Linux kernel installation that has not applied the bug fix will be vulnerable. The vulnerability is present in all kernel versions where the ccp/sev-dev-tsm driver contains the flawed dsm_create implementation. Because the fix was authored in the kernel source, distributions that have incorporated the patch into their kernel releases are no longer impacted; all other distributions remain affected until they update to a kernel version that contains the change.

The CVSS score of 5.5 indicates a moderate severity, while the EPSS score of less than 1% shows a very low likelihood of exploitation in the wild. The flaw remains a local kernel vulnerability – an attacker would need to trigger dsm_create, for example by loading a malicious module or executing privileged code that reaches the SEV device. No public exploit exists and the vulnerability is not listed in the CISA KEV catalog. While the attack would still only deny service by causing a kernel crash, the combination of moderate severity and very low exploitation probability suggests a lower overall risk, although it remains significant for systems that run untrusted kernel modules or expose SEV functionality to privileged users.