{"id":"CVE-2026-93237","revision":"03f0dce642a14b4f92dcd12e9126ab45","records":[{"revision":"03f0dce642a14b4f92dcd12e9126ab45","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-93237","aliases":[],"title":"LoongArch: Add DIRECT_MAP_PHYSMEM_END definition","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nLoongArch: Add DIRECT_MAP_PHYSMEM_END definition\n\nget_free_mem_region() and mhp_get_pluggable_range() bound their search\nto DIRECT_MAP_PHYSMEM_END. LoongArch does not define it, so the fallback\nin include/linux/mm.h applies: under CONFIG_SPARSEMEM_VMEMMAP it is\n(1ULL << MAX_PHYSMEM_BITS) - 1, a compile-time constant that does not\nadapt to the CPU's physical address space bits (cpu_pabits, probed from\nCPUCFG1).\n\nThe vmemmap window only covers physical space below 2^(cpu_pabits+1)\n(i.e. VMEMMAP_SIZE), so on CPUs with fewer physical address bits than\nMAX_PHYSMEM_BITS the fallback allows get_free_mem_region() to return\na ZONE_DEVICE region outside the vmemmap window; vmemmap_populate() then\nwraps the memmap range around and maps it into low memory, silently\ncorrupting the page tables. The same search also picked the top-of-\naddress-space region that crashed memmap_init_zone_device() with amdkfd\non Loongson-3C6000 in 6.16 [1]; the commit 2969b42c8f99 (\"LoongArch/mm:\nalign vmemmap to maximal folio size\") keeps that region in bounds on\ncurrent Loongson-3C6000 configs, but CPUs with smaller cpu_pabits (e.g.\nthe Loongson-2K series) are still affected.\n\nDefine DIRECT_MAP_PHYSMEM_END as the vmemmap-covered physical range,\n(1ULL << (cpu_pabits + 1)) - 1, capped at (1ULL << MAX_PHYSMEM_BITS) - 1\nunder CONFIG_SPARSEMEM, similar to the commit f3336b48cf9d (\"riscv: mm:\nDefine DIRECT_MAP_PHYSMEM_END\").\n\n[1] https://lore.kernel.org/amd-gfx/20250814032153.227285-1-jeffbai@aosc.io/","state":0,"publishedAt":"2026-09-24T15:33:51.702+00:00","modifiedAt":"2026-10-19T09:07:48.863+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"arch/loongarch/include/asm/pgtable.h\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"7b09f5af01ede480cbe7abcb281cf17550a46ff5\",\n                            \"lessThan\": \"ab275a23b4d9f04ca6c2f5f6a3246194e045a761\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"7b09f5af01ede480cbe7abcb281cf17550a46ff5\",\n                            \"lessThan\": \"55e18311c705cceef6c34d522ea387b1f0069bab\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"7b09f5af01ede480cbe7abcb281cf17550a46ff5\",\n                            \"lessThan\": \"2677f97a67fdbc62a82ce1faa67791f54451d36f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"arch/loongarch/include/asm/pgtable.h\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.2\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.2\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.51\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.5\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/ab275a23b4d9f04ca6c2f5f6a3246194e045a761","https://git.kernel.org/stable/c/55e18311c705cceef6c34d522ea387b1f0069bab","https://git.kernel.org/stable/c/2677f97a67fdbc62a82ce1faa67791f54451d36f"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-93237","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-93237","identifiers":["CVE-2026-93237"]},"retained":false,"historicalAffected":[]}],"coverage":[]}