{"id":"CVE-2025-39845","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nx86/mm/64: define ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings()\n\nDefine ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings() to ensure\npage tables are …","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nx86/mm/64: define ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings()\n\nDefine ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings() to ensure\npage tables are …","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-401"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 5.13, < 5.15.192","linux_kernel >= 5.16, < 6.1.151","linux_kernel >= 6.2, < 6.6.105","linux_kernel >= 6.7, < 6.12.46","linux_kernel >= 6.13, < 6.16.6","linux_kernel = 6.17","debian_linux = 11.0"],"patched":["linux_kernel 6.16.6"],"published":"2025-09-19","updated":"2026-10-15","sourceUpdated":"2026-10-15T02:18:01.910","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-39845","references":[{"url":"https://git.kernel.org/stable/c/26ff568f390a531d1bd792e49f1a401849921960","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5f761d40ee95d2624f839c90ebeef2d5c55007f5","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6659d027998083fbb6d42a165b0c90dc2e8ba989","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6bf9473727569e8283c1e2445c7ac42cf4fc9fa9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/744ff519c72de31344a627eaf9b24e9595aae554","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b7f4051dd3388edd30e9a6077c05c486aa31e0d4","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-032379.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-457936.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00157,"epssPercentile":0.04848,"ingestedAt":"2026-09-08T15:33:26.996Z","slug":"CVE-2025-39845","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nx86/mm/64: define ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings()\n\nDefine ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings() to ensure\npage tables are properly synchronized when calling p*d_populate_kernel().\n\nFor 5-level paging, synchronization is performed via\npgd_populate_kernel().  In 4-level paging, pgd_populate() is a no-op, so\nsynchronization is instead performed at the P4D level via\np4d_populate_kernel().\n\nThis fixes intermittent boot failures on systems using 4-level paging and\na large amount of persistent memory:\n\n  BUG: unable to handle page fault for address: ffffe70000000034\n  #PF: supervisor write access in kernel mode\n  #PF: error_code(0x0002) - not-present page\n  PGD 0 P4D 0\n  Oops: 0002 [#1] SMP NOPTI\n  RIP: 0010:__init_single_page+0x9/0x6d\n  Call Trace:\n   <TASK>\n   __init_zone_device_page+0x17/0x5d\n   memmap_init_zone_device+0x154/0x1bb\n   pagemap_range+0x2e0/0x40f\n   memremap_pages+0x10b/0x2f0\n   devm_memremap_pages+0x1e/0x60\n   dev_dax_probe+0xce/0x2ec [device_dax]\n   dax_bus_probe+0x6d/0xc9\n   [... snip ...]\n   </TASK>\n\nIt also fixes a crash in vmemmap_set_pmd() caused by accessing vmemmap\nbefore sync_global_pgds() [1]:\n\n  BUG: unable to handle page fault for address: ffffeb3ff1200000\n  #PF: supervisor write access in kernel mode\n  #PF: error_code(0x0002) - not-present page\n  PGD 0 P4D 0\n  Oops: Oops: 0002 [#1] PREEMPT SMP NOPTI\n  Tainted: [W]=WARN\n  RIP: 0010:vmemmap_set_pmd+0xff/0x230\n   <TASK>\n   vmemmap_populate_hugepages+0x176/0x180\n   vmemmap_populate+0x34/0x80\n   __populate_section_memmap+0x41/0x90\n   sparse_add_section+0x121/0x3e0\n   __add_pages+0xba/0x150\n   add_pages+0x1d/0x70\n   memremap_pages+0x3dc/0x810\n   devm_memremap_pages+0x1c/0x60\n   xe_devm_add+0x8b/0x100 [xe]\n   xe_tile_init_noalloc+0x6a/0x70 [xe]\n   xe_device_probe+0x48c/0x740 [xe]\n   [... snip ...]\n\n## Affected\n\n- `linux_kernel >= 5.13, < 5.15.192`\n- `linux_kernel >= 5.16, < 6.1.151`\n- `linux_kernel >= 6.2, < 6.6.105`\n- `linux_kernel >= 6.7, < 6.12.46`\n- `linux_kernel >= 6.13, < 6.16.6`\n- `linux_kernel = 6.17`\n- `debian_linux = 11.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.16.6`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":221557,"id":"CVE-2025-39845","ts":1792035260835,"field":"cvss","old":null,"new":"5.5"},{"seq":221556,"id":"CVE-2025-39845","ts":1792035260835,"field":"severity","old":"none","new":"medium"}]}