{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2022-49778",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2025-04-16T07:17:33.805Z",
        "datePublished": "2025-05-01T14:09:13.828Z",
        "dateUpdated": "2026-05-11T19:06:36.025Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-05-11T19:06:36.025Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\narm64/mm: fix incorrect file_map_count for non-leaf pmd/pud\n\nThe page table check trigger BUG_ON() unexpectedly when collapse hugepage:\n\n ------------[ cut here ]------------\n kernel BUG at mm/page_table_check.c:82!\n Internal error: Oops - BUG: 00000000f2000800 [#1] SMP\n Dumping ftrace buffer:\n    (ftrace buffer empty)\n Modules linked in:\n CPU: 6 PID: 68 Comm: khugepaged Not tainted 6.1.0-rc3+ #750\n Hardware name: linux,dummy-virt (DT)\n pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)\n pc : page_table_check_clear.isra.0+0x258/0x3f0\n lr : page_table_check_clear.isra.0+0x240/0x3f0\n[...]\n Call trace:\n  page_table_check_clear.isra.0+0x258/0x3f0\n  __page_table_check_pmd_clear+0xbc/0x108\n  pmdp_collapse_flush+0xb0/0x160\n  collapse_huge_page+0xa08/0x1080\n  hpage_collapse_scan_pmd+0xf30/0x1590\n  khugepaged_scan_mm_slot.constprop.0+0x52c/0xac8\n  khugepaged+0x338/0x518\n  kthread+0x278/0x2f8\n  ret_from_fork+0x10/0x20\n[...]\n\nSince pmd_user_accessible_page() doesn't check if a pmd is leaf, it\ndecrease file_map_count for a non-leaf pmd comes from collapse_huge_page().\nand so trigger BUG_ON() unexpectedly.\n\nFix this problem by using pmd_leaf() insteal of pmd_present() in\npmd_user_accessible_page(). Moreover, use pud_leaf() for\npud_user_accessible_page() too."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "arch/arm64/include/asm/pgtable.h"
                    ],
                    "versions": [
                        {
                            "version": "42b2547137f5c974bb1bfd657c869fe96b96d86f",
                            "lessThan": "2d458046df634088611d44fd77f45465e833ef78",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "42b2547137f5c974bb1bfd657c869fe96b96d86f",
                            "lessThan": "5b47348fc0b18a78c96f8474cc90b7525ad1bbfe",
                            "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/arm64/include/asm/pgtable.h"
                    ],
                    "versions": [
                        {
                            "version": "5.19",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "5.19",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.0.10",
                            "lessThanOrEqual": "6.0.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.1",
                            "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": "6.0.10"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "5.19",
                                    "versionEndExcluding": "6.1"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/2d458046df634088611d44fd77f45465e833ef78"
                },
                {
                    "url": "https://git.kernel.org/stable/c/5b47348fc0b18a78c96f8474cc90b7525ad1bbfe"
                }
            ],
            "title": "arm64/mm: fix incorrect file_map_count for non-leaf pmd/pud",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}