{"cve":"CVE-2022-48897","nvd":{"published":"2024-08-21T07:15:05.693","modified":"2026-06-17T05:16:33.413","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\narm64/mm: fix incorrect file_map_count for invalid pmd\n\nThe page table check trigger BUG_ON() unexpectedly when split hugepage:\n\n ------------[ cut here ]------------\n kernel BUG at mm/page_table_check.c:119!\n Internal error: Oops - BUG: 00000000f2000800 [#1] SMP\n Dumping ftrace buffer:\n    (ftrace buffer empty)\n Modules linked in:\n CPU: 7 PID: 210 Comm: transhuge-stres Not tainted 6.1.0-rc3+ #748\n Hardware name: linux,dummy-virt (DT)\n pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)\n pc : page_table_check_set.isra.0+0x398/0x468\n lr : page_table_check_set.isra.0+0x1c0/0x468\n[...]\n Call trace:\n  page_table_check_set.isra.0+0x398/0x468\n  __page_table_check_pte_set+0x160/0x1c0\n  __split_huge_pmd_locked+0x900/0x1648\n  __split_huge_pmd+0x28c/0x3b8\n  unmap_page_range+0x428/0x858\n  unmap_single_vma+0xf4/0x1c8\n  zap_page_range+0x2b0/0x410\n  madvise_vma_behavior+0xc44/0xe78\n  do_madvise+0x280/0x698\n  __arm64_sys_madvise+0x90/0xe8\n  invoke_syscall.constprop.0+0xdc/0x1d8\n  do_el0_svc+0xf4/0x3f8\n  el0_svc+0x58/0x120\n  el0t_64_sync_handler+0xb8/0xc0\n  el0t_64_sync+0x19c/0x1a0\n[...]\n\nOn arm64, pmd_leaf() will return true even if the pmd is invalid due to\npmd_present_invalid() check. So in pmdp_invalidate() the file_map_count\nwill not only decrease once but also increase once. Then in set_pte_at(),\nthe file_map_count increase again, and so trigger BUG_ON() unexpectedly.\n\nAdd !pmd_present_invalid() check in pmd_user_accessible_page() to fix the\nproblem.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/21e5eca0ac9046da9918a919bc92b7b5a78d27e7","https://git.kernel.org/stable/c/74c2f81054510d45b813548cb0a1c4ebf87cdd5f"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:54:16.205165117+00:00"},"epss":{"cve":"CVE-2022-48897","score":0.00205,"percentile":0.10507,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}