{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-37956", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:23.974Z", "datePublished": "2025-05-20T16:01:49.865Z", "dateUpdated": "2026-08-05T11:58:38.144Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:58:38.144Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: prevent rename with empty string\n\nClient can send empty newname string to ksmbd server.\nIt will cause a kernel oops from d_alloc.\nThis patch return the error when attempting to rename\na file or directory with an empty new name string." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - ksmbd is the in-kernel SMB server; the malformed FILE_RENAME_INFORMATION request arrives over TCP/445 (or SMB-Direct) from a remote client. No local access is involved.\nAC:L - The attacker deterministically triggers the uninitialized-qstr dereference by sending one SET_INFO request with FileNameLength=2 containing a UTF-16 NUL; no race or unpredictable precondition is required, and the stack residue that shapes the outcome is influenced by the attacker's own preceding requests on the same ksmbd worker.\nPR:L - smb2_set_info requires an established session, a tree connect to a writable share, and an open handle with FILE_DELETE access, so a low-privileged authenticated SMB account (or a guest-mapped session on guest-enabled shares) is needed. This matches sibling post-auth ksmbd CVEs such as CVE-2025-22040/22041.\nUI:N - The server processes the crafted rename request automatically in its worker thread; no action by any local user or administrator is needed.\nS:U - The wild read, dentry corruption and crash all occur within the kernel's own security authority; no VM, IOMMU or sandbox boundary is crossed.\nC:H - __d_alloc() memcpy's from an uninitialized kernel-stack pointer with an uncontrolled length — an unbounded out-of-bounds read whose contents become the new dentry name, which the attacker can then read back over SMB via directory enumeration, disclosing kernel heap/stack data and pointers.\nI:H - The rename completes against a target derived from uninitialized kernel memory and leaves a dentry cached with a bogus d_name.len driving later name-switching memcpy's; on 32-bit ksmbd builds the `size + name->len` computation in __d_alloc() overflows, producing an undersized allocation followed by a multi-gigabyte memcpy — a heap write primitive.\nA:H - The commit states the empty name causes a kernel oops from d_alloc; a remote client can repeat the request at will to keep panicking the server, so availability loss is total." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/server/smb2pdu.c" ], "versions": [ { "version": "0626e6641f6b467447c81dd7678a69c66f7746cf", "lessThan": "6ee551672c8cf36108b0cfba92ec0c7c28ac3439", "status": "affected", "versionType": "git" }, { "version": "0626e6641f6b467447c81dd7678a69c66f7746cf", "lessThan": "c57301e332cc413fe0a7294a90725f4e21e9549d", "status": "affected", "versionType": "git" }, { "version": "0626e6641f6b467447c81dd7678a69c66f7746cf", "lessThan": "d7f2c00acb1ef64304fd40ac507e9213ff1d9b5c", "status": "affected", "versionType": "git" }, { "version": "0626e6641f6b467447c81dd7678a69c66f7746cf", "lessThan": "53e3e5babc0963a92d856a5ec0ce92c59f54bc12", "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/smb2pdu.c" ], "versions": [ { "version": "5.15", "status": "affected" }, { "version": "0", "lessThan": "5.15", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.91", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.29", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.14.7", "lessThanOrEqual": "6.14.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.15", "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": "5.15", "versionEndExcluding": "6.6.91" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.12.29" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.14.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.15" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/6ee551672c8cf36108b0cfba92ec0c7c28ac3439" }, { "url": "https://git.kernel.org/stable/c/c57301e332cc413fe0a7294a90725f4e21e9549d" }, { "url": "https://git.kernel.org/stable/c/d7f2c00acb1ef64304fd40ac507e9213ff1d9b5c" }, { "url": "https://git.kernel.org/stable/c/53e3e5babc0963a92d856a5ec0ce92c59f54bc12" } ], "title": "ksmbd: prevent rename with empty string", "x_generator": { "engine": "bippy-1.2.0" } } } }