{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-72043",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-08-09T03:40:39.902Z",
        "datePublished": "2026-08-15T05:52:02.505Z",
        "dateUpdated": "2026-08-15T05:52:02.505Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-15T05:52:02.505Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nLoongArch: Fix missing dirty page tracking in {pte,pmd}_wrprotect()\n\nWhen hardware page table walker (PTW) is enabled on LoongArch, the CPU\nmay set _PAGE_DIRTY directly in the page table entry during a write TLB\nmiss, without going through the software TLB store handler. The software\nTLB store handler (tlbex.S:254) sets both _PAGE_DIRTY and_PAGE_MODIFIED\ntogether:\n\n    ori t0, t0, (_PAGE_VALID | _PAGE_DIRTY | _PAGE_MODIFIED)\n\nSince hardware PTW only sets _PAGE_DIRTY, the software-only bit, i.e.\n_PAGE_MODIFIED is left unchanged. This creates a window where a PTE has\n_PAGE_DIRTY set (hardware knows the page is dirty) but _PAGE_MODIFIED\nclear (software is unaware).\n\nWhen fork()/clone() triggers copy-on-write, __copy_present_ptes() calls\npte_wrprotect(), which unconditionally clears both the _PAGE_WRITE and\n_PAGE_DIRTY bits:\n\n    pte_val(pte) &= ~(_PAGE_WRITE | _PAGE_DIRTY);\n\nSince _PAGE_MODIFIED was never set, the dirtiness information is lost\ncompletely. Subsequently, when memory pressure triggers page reclaim,\npage_mkclean() / try_to_unmap() sees the page as clean (i.e. pte_dirty()\nreturns false) and the page may be freed without writeback, causing data\ncorruption.\n\nFix this by propagating the _PAGE_DIRTY bit to the _PAGE_MODIFIED bit in\nboth pte_wrprotect() and pmd_wrprotect() before clearing writeable bits:\n\n    if (pte_val(pte) & _PAGE_DIRTY)\n        pte_val(pte) |= _PAGE_MODIFIED;\n\nThe pmd_wrprotect() fix handles the CONFIG_TRANSPARENT_HUGEPAGE case,\nwhere pmd entries need the same treatment.\n\nThis ensures the software dirty tracking bit (checked by pte_dirty() and\npmd_dirty(), which read both the _PAGE_DIRTY and _PAGE_MODIFIED bits) is\npreserved across fork COW write-protection.\n\nThe issue was found by the LTP madvise09 test case, which exercises page\nreclaim after \"madvise(MADV_FREE), write and fork\" operation sequence on\nprivate anonymous mappings."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "arch/loongarch/include/asm/pgtable.h"
                    ],
                    "versions": [
                        {
                            "version": "09cfefb7fa70c3af011b0db0a513fd80b2f18abc",
                            "lessThan": "76f88650763a35cbf1384c65d66d096fa31cc58d",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "09cfefb7fa70c3af011b0db0a513fd80b2f18abc",
                            "lessThan": "e8a916579e427af32f2de8213dfa23c5df6e6664",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "09cfefb7fa70c3af011b0db0a513fd80b2f18abc",
                            "lessThan": "39bb21a4bff0d70058bf752d7b5aa2e2ccc864a9",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "09cfefb7fa70c3af011b0db0a513fd80b2f18abc",
                            "lessThan": "a65f49b6f7ece756394f8f0e85570020e7fd0e35",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "09cfefb7fa70c3af011b0db0a513fd80b2f18abc",
                            "lessThan": "e483da960892c41fa7f0cf0d2fc2410d65a483d6",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "09cfefb7fa70c3af011b0db0a513fd80b2f18abc",
                            "lessThan": "018e9828eb523c638fa3d9bdf0fd4956b74555b2",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "arch/loongarch/include/asm/pgtable.h"
                    ],
                    "versions": [
                        {
                            "version": "5.19",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "5.19",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.1.178",
                            "lessThanOrEqual": "6.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.145",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.97",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.40",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1.5",
                            "lessThanOrEqual": "7.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2-rc1",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.19",
                                    "versionEndExcluding": "6.1.178"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.19",
                                    "versionEndExcluding": "6.6.145"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.19",
                                    "versionEndExcluding": "6.12.97"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.19",
                                    "versionEndExcluding": "6.18.40"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.19",
                                    "versionEndExcluding": "7.1.5"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.19",
                                    "versionEndExcluding": "7.2-rc1"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/76f88650763a35cbf1384c65d66d096fa31cc58d"
                },
                {
                    "url": "https://git.kernel.org/stable/c/e8a916579e427af32f2de8213dfa23c5df6e6664"
                },
                {
                    "url": "https://git.kernel.org/stable/c/39bb21a4bff0d70058bf752d7b5aa2e2ccc864a9"
                },
                {
                    "url": "https://git.kernel.org/stable/c/a65f49b6f7ece756394f8f0e85570020e7fd0e35"
                },
                {
                    "url": "https://git.kernel.org/stable/c/e483da960892c41fa7f0cf0d2fc2410d65a483d6"
                },
                {
                    "url": "https://git.kernel.org/stable/c/018e9828eb523c638fa3d9bdf0fd4956b74555b2"
                }
            ],
            "title": "LoongArch: Fix missing dirty page tracking in {pte,pmd}_wrprotect()",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}