CVE-2026-72043 - Vulnerability Details

Vendors	Products
Linux	Linux Kernel

Vendors	Products
Linux	Linux Kernel

Link	Providers
https://git.kernel.org/stable/c/018e9828eb523c638fa3d9bdf0fd4956b74555b2
https://git.kernel.org/stable/c/39bb21a4bff0d70058bf752d7b5aa2e2ccc864a9
https://git.kernel.org/stable/c/76f88650763a35cbf1384c65d66d096fa31cc58d
https://git.kernel.org/stable/c/a65f49b6f7ece756394f8f0e85570020e7fd0e35
https://git.kernel.org/stable/c/e483da960892c41fa7f0cf0d2fc2410d65a483d6
https://git.kernel.org/stable/c/e8a916579e427af32f2de8213dfa23c5df6e6664

Type	Values Removed	Values Added
Weaknesses		CWE-362

Type	Values Removed	Values Added
Description		In the Linux kernel, the following vulnerability has been resolved: LoongArch: Fix missing dirty page tracking in {pte,pmd}_wrprotect() When hardware page table walker (PTW) is enabled on LoongArch, the CPU may set _PAGE_DIRTY directly in the page table entry during a write TLB miss, without going through the software TLB store handler. The software TLB store handler (tlbex.S:254) sets both _PAGE_DIRTY and_PAGE_MODIFIED together: ori t0, t0, (_PAGE_VALID \| _PAGE_DIRTY \| _PAGE_MODIFIED) Since hardware PTW only sets _PAGE_DIRTY, the software-only bit, i.e. _PAGE_MODIFIED is left unchanged. This creates a window where a PTE has _PAGE_DIRTY set (hardware knows the page is dirty) but _PAGE_MODIFIED clear (software is unaware). When fork()/clone() triggers copy-on-write, __copy_present_ptes() calls pte_wrprotect(), which unconditionally clears both the _PAGE_WRITE and _PAGE_DIRTY bits: pte_val(pte) &= ~(_PAGE_WRITE \| _PAGE_DIRTY); Since _PAGE_MODIFIED was never set, the dirtiness information is lost completely. Subsequently, when memory pressure triggers page reclaim, page_mkclean() / try_to_unmap() sees the page as clean (i.e. pte_dirty() returns false) and the page may be freed without writeback, causing data corruption. Fix this by propagating the _PAGE_DIRTY bit to the _PAGE_MODIFIED bit in both pte_wrprotect() and pmd_wrprotect() before clearing writeable bits: if (pte_val(pte) & _PAGE_DIRTY) pte_val(pte) \|= _PAGE_MODIFIED; The pmd_wrprotect() fix handles the CONFIG_TRANSPARENT_HUGEPAGE case, where pmd entries need the same treatment. This ensures the software dirty tracking bit (checked by pte_dirty() and pmd_dirty(), which read both the _PAGE_DIRTY and _PAGE_MODIFIED bits) is preserved across fork COW write-protection. The issue was found by the LTP madvise09 test case, which exercises page reclaim after "madvise(MADV_FREE), write and fork" operation sequence on private anonymous mappings.
Title		LoongArch: Fix missing dirty page tracking in {pte,pmd}_wrprotect()
First Time appeared		Linux Linux linux Kernel
CPEs		cpe:2.3:o:linux:linux_kernel::::::::
Vendors & Products		Linux Linux linux Kernel
References		https://git.kernel.org/stable/c/018e9828eb523c638fa3d9bdf0fd4956b74555b2 https://git.kernel.org/stable/c/39bb21a4bff0d70058bf752d7b5aa2e2ccc864a9 https://git.kernel.org/stable/c/76f88650763a35cbf1384c65d66d096fa31cc58d https://git.kernel.org/stable/c/a65f49b6f7ece756394f8f0e85570020e7fd0e35 https://git.kernel.org/stable/c/e483da960892c41fa7f0cf0d2fc2410d65a483d6 https://git.kernel.org/stable/c/e8a916579e427af32f2de8213dfa23c5df6e6664

{"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"}}}}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["arch/loongarch/include/asm/pgtable.h"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "76f88650763a35cbf1384c65d66d096fa31cc58d", "status": "affected", "version": "09cfefb7fa70c3af011b0db0a513fd80b2f18abc", "versionType": "git"}, {"lessThan": "e8a916579e427af32f2de8213dfa23c5df6e6664", "status": "affected", "version": "09cfefb7fa70c3af011b0db0a513fd80b2f18abc", "versionType": "git"}, {"lessThan": "39bb21a4bff0d70058bf752d7b5aa2e2ccc864a9", "status": "affected", "version": "09cfefb7fa70c3af011b0db0a513fd80b2f18abc", "versionType": "git"}, {"lessThan": "a65f49b6f7ece756394f8f0e85570020e7fd0e35", "status": "affected", "version": "09cfefb7fa70c3af011b0db0a513fd80b2f18abc", "versionType": "git"}, {"lessThan": "e483da960892c41fa7f0cf0d2fc2410d65a483d6", "status": "affected", "version": "09cfefb7fa70c3af011b0db0a513fd80b2f18abc", "versionType": "git"}, {"lessThan": "018e9828eb523c638fa3d9bdf0fd4956b74555b2", "status": "affected", "version": "09cfefb7fa70c3af011b0db0a513fd80b2f18abc", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["arch/loongarch/include/asm/pgtable.h"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.19"}, {"lessThan": "5.19", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.178", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.145", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.97", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.40", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.5", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2-rc1", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "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."}], "id": "CVE-2026-72043", "lastModified": "2026-08-15T06:21:13.480", "metrics": {}, "published": "2026-08-15T06:21:13.480", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/018e9828eb523c638fa3d9bdf0fd4956b74555b2"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/39bb21a4bff0d70058bf752d7b5aa2e2ccc864a9"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/76f88650763a35cbf1384c65d66d096fa31cc58d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a65f49b6f7ece756394f8f0e85570020e7fd0e35"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e483da960892c41fa7f0cf0d2fc2410d65a483d6"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e8a916579e427af32f2de8213dfa23c5df6e6664"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[09cfefb7fa70c3af011b0db0a513fd80b2f18abc,76f88650763a35cbf1384c65d66d096fa31cc58d)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[09cfefb7fa70c3af011b0db0a513fd80b2f18abc,e8a916579e427af32f2de8213dfa23c5df6e6664)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[09cfefb7fa70c3af011b0db0a513fd80b2f18abc,39bb21a4bff0d70058bf752d7b5aa2e2ccc864a9)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[09cfefb7fa70c3af011b0db0a513fd80b2f18abc,a65f49b6f7ece756394f8f0e85570020e7fd0e35)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[09cfefb7fa70c3af011b0db0a513fd80b2f18abc,e483da960892c41fa7f0cf0d2fc2410d65a483d6)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[09cfefb7fa70c3af011b0db0a513fd80b2f18abc,018e9828eb523c638fa3d9bdf0fd4956b74555b2)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "5.19"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,5.19)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.1.178,6.1.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.6.145,6.6.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.12.97,6.12.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.18.40,6.18.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.1.5,7.1.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2-rc1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-08-15T10:45:06.866111+00:00", "updated": "2026-08-15T20:45:03.119804+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-362"]}

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