{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-64140",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-07-19T07:54:57.037Z",
        "datePublished": "2026-07-19T15:40:33.194Z",
        "dateUpdated": "2026-08-05T12:39:40.506Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T12:39:40.506Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix null pointer dereference in proc_show_files()\n\nWhen a SMB2 client opens a file with a durable v2 handle and then issues\nSMB2 SESSION_LOGOFF, session_fd_check() clears fp->tcon = NULL on the\nreconnectable file pointer but leaves the fp registered in global_ft.idr\nuntil the durable scavenger fires (up to fp->durable_timeout seconds\nlater).\n\nDuring that window any read of /proc/fs/ksmbd/files (mode 0400) panics\nthe kernel because proc_show_files() walks global_ft.idr and\nunconditionally dereferences fp->tcon->id with no NULL guard.\n\nReproducer requires only a successful SMB2 SESSION_SETUP and a share\nconfigured with 'durable handles = yes'. KASAN report on mainline\n70390501d194:\n\n  general protection fault, probably for non-canonical address\n  0xdffffc0000000000: 0000 [#1] SMP KASAN PTI\n  KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]\n  RIP: 0010:proc_show_files+0x118/0x740\n  Call Trace:\n   proc_show_files+0x118/0x740\n   seq_read_iter+0x4ef/0xe10\n   proc_reg_read_iter+0x1b7/0x280\n   ...\n\nGuard the dereference. A durable-disconnected fp legitimately has no\ntcon; report its tree id as 0 rather than oopsing."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                        "baseScore": 7.5,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:N - The poisoned durable-handle state is created remotely over ksmbd's TCP/445 SMB2 path (SESSION_SETUP, TREE_CONNECT, CREATE with durable v2, SESSION_LOGOFF); ksmbd is a network-facing in-kernel SMB server per kernel CVSS guidance.\nAC:L - An attacker fully controls the SMB2 sequence that leaves `fp->tcon = NULL` while the file remains in `global_ft.idr`; once that state exists, any read of `/proc/fs/ksmbd/files` deterministically oopses, and the window lasts up to `fp->durable_timeout` seconds (repeatable).\nPR:N - Exploitation requires only network reachability to ksmbd plus a successful SMB2 SESSION_SETUP (guest or any configured share account); no host root or kernel capabilities are needed on the attacker side to plant the corrupt durable-handle entry.\nUI:N - No victim user action (opening files, mounting shares, clicking links) is required; the crash is triggered by kernel procfs iteration, not by end-user interaction.\nS:U - Impact is a kernel NULL pointer dereference/panic within the ksmbd/kernel security authority; it does not cross VM, IOMMU, or sandbox boundaries.\nC:N - This is a pure NULL pointer dereference at `fp->tcon->id` with no out-of-bounds read, UAF, or other memory corruption that could leak kernel data.\nI:N - The bug is a read of address 0 through a NULL `fp->tcon` pointer; it provides no write primitive, type confusion, or control-flow hijack opportunity.\nA:H - Unconditional dereference of NULL `fp->tcon` in `proc_show_files()` causes a kernel general protection fault/oops (KASAN null-ptr-deref), crashing or severely disrupting the host."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/smb/server/vfs_cache.c"
                    ],
                    "versions": [
                        {
                            "version": "b38f99c1217ae04753340f0fdcd8f35bf56841dc",
                            "lessThan": "8eab081627b67216d1c8f638b68289b500dc9a6b",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "b38f99c1217ae04753340f0fdcd8f35bf56841dc",
                            "lessThan": "904901561e61a2b559070b20c74a8c95491f30aa",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/smb/server/vfs_cache.c"
                    ],
                    "versions": [
                        {
                            "version": "7.0",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "7.0",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.0.11",
                            "lessThanOrEqual": "7.0.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1",
                            "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": "7.0",
                                    "versionEndExcluding": "7.0.11"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "7.0",
                                    "versionEndExcluding": "7.1"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/8eab081627b67216d1c8f638b68289b500dc9a6b"
                },
                {
                    "url": "https://git.kernel.org/stable/c/904901561e61a2b559070b20c74a8c95491f30aa"
                }
            ],
            "title": "ksmbd: fix null pointer dereference in proc_show_files()",
            "x_generator": {
                "engine": "bippy-1.2.0"
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}