In the Linux kernel, the function p2pmem_alloc_mmap() asserts that a memory page has a non‑zero reference count before mapping it for PCI peer‑to‑peer DMA. Earlier releases mistakenly set the initial reference count to zero, causing the assertion to trigger when CONFIG_DEBUG_VM is enabled, which generates a VM warning. The patch corrects the assertion to use page_ref_count(page), preventing the warning and potential kernel instability.

All Linux kernel binaries that do not contain commit b7e282378773 are affected. The vulnerability is present in any kernel source that has not incorporated this patch, regardless of distribution. Specific distribution version numbers are not provided, so any kernel build prior to the inclusion of the commit may be impacted.

The flaw is exercised only with CONFIG_DEBUG_VM active, a flag normally disabled in production systems, so the probability of exploitation is low and the EPSS score of < 1% reflects limited observed exploitation. The CVSS score of 5.5 denotes a medium severity assessment. The issue does not provide a direct exploit path for privilege escalation or remote code execution; it results in a kernel warning rather than a crash or denial of service. The vulnerability is not listed in CISA KEV.