CVE-2026-64295

{"id": "CVE-2026-64295", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}]}, "affected": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "affectedData": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "9039b9096ea27a20f0349d1537537663c935c8ed", "lessThan": "8dcaa0f87a88d720d13106f3a306c6b61d189d86", "versionType": "git"}, {"status": "affected", "version": "9039b9096ea27a20f0349d1537537663c935c8ed", "lessThan": "377b1cd6bbcf327338cd951cc2fd74bc75540235", "versionType": "git"}, {"status": "affected", "version": "9039b9096ea27a20f0349d1537537663c935c8ed", "lessThan": "ffd017237cfe99e6e5602ab14179b0e6878a0840", "versionType": "git"}], "programFiles": ["include/linux/page_ext.h"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "6.15"}, {"status": "unaffected", "version": "0", "lessThan": "6.15", "versionType": "semver"}, {"status": "unaffected", "version": "6.18.39", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.1.4", "versionType": "semver", "lessThanOrEqual": "7.1.*"}, {"status": "unaffected", "version": "7.2-rc3", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["include/linux/page_ext.h"], "defaultStatus": "affected"}]}], "published": "2026-07-25T10:17:10.277", "references": [{"url": "https://git.kernel.org/stable/c/377b1cd6bbcf327338cd951cc2fd74bc75540235", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/8dcaa0f87a88d720d13106f3a306c6b61d189d86", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/ffd017237cfe99e6e5602ab14179b0e6878a0840", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-476"}]}], "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."}], "lastModified": "2026-08-12T15:02:07.907", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "1DA3E752-10DF-4260-A04E-FB6A07086768", "versionEndExcluding": "6.18.39", "versionStartIncluding": "6.15"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "6228DDD6-4557-4AA3-9F43-AB995D471E42", "versionEndExcluding": "7.1.4", "versionStartIncluding": "6.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.2:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "5E8B9085-7ADB-4A05-89EF-12949B6A0509"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.2:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "1FC0D50D-9D58-4947-A197-A5A3FF07E7E3"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}