CVE-2026-80682

A flaw was found in the Linux kernel's RISC-V memory management component. An incorrect calculation for memory alignment during system initialization could lead to a kernel warning. This issue arises when the physical memory base address is not properly aligned, potentially causing system instability or a denial of service (DoS) on affected RISC-V systems.

A moderate-impact flaw was found in the Linux kernel's RISC-V memory management code. When computing the start of the vmemmap region, the kernel rounds the physical RAM base address down to an alignment boundary, but a recent upstream change fed an alignment value measured in bytes of struct page storage (MAX_FOLIO_VMEMMAP_ALIGN) directly into a macro that expects a physical-address alignment. On RISC-V systems whose DRAM base address is not aligned to MAX_FOLIO_NR_PAGES * PAGE_SIZE, such as QEMU virt, this unit mismatch triggers a kernel WARNING in sparse_init() during early boot, which can cause system instability or a denial of service. The flaw affects only availability; there is no impact on confidentiality or integrity. Red Hat Product Security rates this flaw Moderate severity with a CVSS 3.1 base score of 5.5 (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H), which is lower than the CVEORG score of 7.8 because the issue only affects system availability. The vulnerable code was introduced in recent upstream kernel development and is not present in Red Hat's shipped kernels: the Red Hat Enterprise Linux and Red Hat In-Vehicle OS kernel and kernel-rt components listed for this CVE are marked not affected (vulnerable code not present), so no changes to Red Hat products are required.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.