CVE-2026-64140

{"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"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/smb/server/vfs_cache.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "8eab081627b67216d1c8f638b68289b500dc9a6b", "status": "affected", "version": "b38f99c1217ae04753340f0fdcd8f35bf56841dc", "versionType": "git"}, {"lessThan": "904901561e61a2b559070b20c74a8c95491f30aa", "status": "affected", "version": "b38f99c1217ae04753340f0fdcd8f35bf56841dc", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/smb/server/vfs_cache.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "7.0"}, {"lessThan": "7.0", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "7.0.*", "status": "unaffected", "version": "7.0.11", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.1", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "1E9C5828-E95C-4C2B-83D6-A3698BA0B1C1", "versionEndExcluding": "7.0.11", "versionStartIncluding": "7.0", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*", "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*", "matchCriteriaId": "0D38F0BF-A728-4133-A358-D44A2F7EE6D6", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*", "matchCriteriaId": "EC732D08-5F7B-46D9-B154-E60C7F4F0A97", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*", "matchCriteriaId": "E5910A9D-F60A-409A-B486-FE66BFEBA9B9", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "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."}], "id": "CVE-2026-64140", "lastModified": "2026-08-18T12:40:01.143", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-07-19T16:17:55.887", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/8eab081627b67216d1c8f638b68289b500dc9a6b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/904901561e61a2b559070b20c74a8c95491f30aa"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-476"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: ksmbd: fix null pointer dereference in proc_show_files()", "id": "2502533", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2502533"}, "csaw": false, "cwe": "CWE-476", "details": ["A flaw was found in the Linux kernel's ksmbd module. A local user, or a remote authenticated user, could trigger a null pointer dereference by reading the `/proc/fs/ksmbd/files` entry after an SMB2 client with a durable handle logs off. This vulnerability can lead to a kernel panic, resulting in a Denial of Service (DoS) for the system."], "name": "CVE-2026-64140", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "impact": "important", "package_name": "erlang27", "product_name": "Red Hat Hardened Images"}], "public_date": "2026-07-19T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-64140\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-64140\nhttps://lore.kernel.org/linux-cve-announce/2026071929-CVE-2026-64140-c119@gregkh/T"]}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[b38f99c1217ae04753340f0fdcd8f35bf56841dc,8eab081627b67216d1c8f638b68289b500dc9a6b)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[b38f99c1217ae04753340f0fdcd8f35bf56841dc,904901561e61a2b559070b20c74a8c95491f30aa)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "7.0"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.0.11,7.1.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-07-21T11:00:05.269473+00:00", "updated": "2026-07-30T20:30:04.631857+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}