Bug 2426042 (CVE-2022-50868)

Summary: CVE-2022-50868 kernel: Kernel: Denial of Service in AMD hwrng due to PCI device refcount leak
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedKeywords: Security
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OS: Linux   
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A flaw was found in the Linux kernel's AMD hardware random number generator (hwrng) component. A local user with low privileges could exploit a PCI device reference count (refcount) leak. This occurs when the `for_each_pci_dev()` loop exits without properly decrementing the PCI device's reference count. This can lead to resource exhaustion and a denial of service (DoS) on the system.
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Description OSIDB Bzimport 2025-12-30 13:04:16 UTC 
In the Linux kernel, the following vulnerability has been resolved:

hwrng: amd - Fix PCI device refcount leak

for_each_pci_dev() is implemented by pci_get_device(). The comment of
pci_get_device() says that it will increase the reference count for the
returned pci_dev and also decrease the reference count for the input
pci_dev @from if it is not NULL.

If we break for_each_pci_dev() loop with pdev not NULL, we need to call
pci_dev_put() to decrease the reference count. Add the missing
pci_dev_put() for the normal and error path.
Comment 1 Alexander B 2025-12-31 13:29:42 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025123050-CVE-2022-50868-8968@gregkh/T