CVE Catalog

CVE-2026-74524

Low risk· EPSS 7%
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.17%

7th percentile - higher than 7% of all known CVEs

Summary

In the Linux kernel for RISC-V, a vulnerability was found causing out-of-bounds page-table walk during memory hot-remove. Functions remove_pud_mapping() and remove_p4d_mapping() obtain a child table base with offset 0, then add the index for addr. With page-table folding, this can walk past the parent table and pass an invalid page to __free_pages(), causing a kernel BUG.

Risk Assessment

The vulnerability can lead to kernel panic during memory removal operations, potentially causing system unavailability or data loss.

Recommendation

Apply the kernel patch that only adds the index when the corresponding page-table level is enabled. Update the system to a kernel version containing this fix.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: riscv: mm: Fix out-of-bounds page-table walk during memory hot-remove remove_pud_mapping() and remove_p4d_mapping() obtain a child table base with pud_offset(p4dp, 0) and p4d_offset(pgd, 0), then add the index for addr. RISC-V folds page-table levels at runtime. When a level is folded, its offset helper returns the parent entry itself, but the index can still be nonzero. Adding it walks past the parent table. Sv48 folds P4D, while Sv39 folds both P4D and PUD, so memory hot-remove can descend into unrelated memory and pass an invalid page to __free_pages(). This can trigger: kernel BUG at include/linux/mm.h:1810! VM_BUG_ON_PAGE(page_ref_count(page) == 0) arch_remove_memory+0x1e/0x5c try_remove_memory+0x15e/0x200 remove_memory+0x24/0x3c Only add the index when the corresponding page-table level is enabled, matching p4d_offset() and pud_offset().

Vulnerability data from NVD (NIST) · CISA KEV · EPSS