{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-64295", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.778Z", "datePublished": "2026-07-25T08:49:33.194Z", "dateUpdated": "2026-07-25T08:49:33.194Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-07-25T08:49:33.194Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm: page_ext: add count limit to page_ext_iter_next to prevent invalid PFN access\n\nThe page_ext iteration API does not validate if the PFN still belongs to a\nvalid section while advancing the iterator. When dynamically adding\nmemory in the hotplug path, it can lead to a NULL pointer dereference\nduring page_ext_lookup at the boundary of the last valid section when\niterator count equals __pgcount.\n\nThe for_each_page_ext() macro calls page_ext_iter_next() as its loop\nincrement. for_each_page_ext() does a \"__page_ext =\npage_ext_iter_next(&__iter)\" at the end. This causes page_ext_iter_next()\nto increment iter->index past __pgcount and call page_ext_lookup(start_pfn\n+ __pgcount). During memory hotplug (online), the PFN at start_pfn +\n__pgcount may belong to a section that has not yet been initialized,\ncausing page_ext_lookup() to trigger a NULL pointer dereference.\n\n[ 14.555124][ T846] Call trace:\n[ 14.555125][ T846] lookup_page_ext+0x6c/0x108 (P)\n[ 14.555127][ T846] page_ext_lookup+0x30/0x3c\n[ 14.555129][ T846] __reset_page_owner+0x11c/0x260\n[ 14.571201][ T846] __free_pages_ok+0x5e8/0x8e0\n[ 14.571204][ T846] __free_pages_core+0x78/0xf0\n[ 14.571206][ T846] generic_online_page+0x14/0x24\n[ 14.597782][ T846] online_pages+0x178/0x30c\n[ 14.597784][ T846] memory_block_change_state+0x284/0x32c\n[ 14.597787][ T846] memory_subsys_online+0x4c/0x64\n[ 14.597789][ T846] device_online+0x88/0xb0\n[ 14.597791][ T846] online_memory_block+0x30/0x40\n[ 14.597793][ T846] walk_memory_blocks+0xac/0xe8\n[ 14.597794][ T846] add_memory_resource+0x280/0x298\n[ 14.656161][ T846] add_memory+0x60/0x98\n\nMove the iteration boundary enforcement inside the iterator functions, so\ncallers cannot inadvertently access beyond the requested range."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/linux/page_ext.h"], "versions": [{"version": "9039b9096ea27a20f0349d1537537663c935c8ed", "lessThan": "8dcaa0f87a88d720d13106f3a306c6b61d189d86", "status": "affected", "versionType": "git"}, {"version": "9039b9096ea27a20f0349d1537537663c935c8ed", "lessThan": "377b1cd6bbcf327338cd951cc2fd74bc75540235", "status": "affected", "versionType": "git"}, {"version": "9039b9096ea27a20f0349d1537537663c935c8ed", "lessThan": "ffd017237cfe99e6e5602ab14179b0e6878a0840", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/linux/page_ext.h"], "versions": [{"version": "6.15", "status": "affected"}, {"version": "0", "lessThan": "6.15", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.39", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.4", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2-rc3", "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": "6.15", "versionEndExcluding": "6.18.39"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15", "versionEndExcluding": "7.1.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.15", "versionEndExcluding": "7.2-rc3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/8dcaa0f87a88d720d13106f3a306c6b61d189d86"}, {"url": "https://git.kernel.org/stable/c/377b1cd6bbcf327338cd951cc2fd74bc75540235"}, {"url": "https://git.kernel.org/stable/c/ffd017237cfe99e6e5602ab14179b0e6878a0840"}], "title": "mm: page_ext: add count limit to page_ext_iter_next to prevent invalid PFN access", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[9039b9096ea27a20f0349d1537537663c935c8ed,8dcaa0f87a88d720d13106f3a306c6b61d189d86)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[9039b9096ea27a20f0349d1537537663c935c8ed,377b1cd6bbcf327338cd951cc2fd74bc75540235)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[9039b9096ea27a20f0349d1537537663c935c8ed,ffd017237cfe99e6e5602ab14179b0e6878a0840)"}}], "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": "generic", "value": "6.15"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,6.15)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.39,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.4,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2-rc3,*]"}}], "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": "2026-07-25T12:15:04.528343+00:00", "updated": "2026-07-25T12:15:04.528377+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}