{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64397", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.785Z", "datePublished": "2026-07-25T08:50:41.620Z", "dateUpdated": "2026-08-17T04:54:51.854Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:54:51.854Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: serialize QUERY_DIRECTORY requests per file\n\nsmb2_query_dir() stores a pointer to its stack-allocated private data in\nthe ksmbd_file readdir_data. Concurrent QUERY_DIRECTORY requests using the\nsame file handle can overwrite this pointer while an iterate_dir() callback\nis still using it, resulting in a stack use-after-free.\n\nAdd a per-file mutex and hold it while accessing the shared directory\nenumeration state. The lock covers scan restart, dot entry state,\nreaddir_data setup and iteration, and response construction. This prevents\nanother request from replacing readdir_data.private before the current\nrequest has finished using it and also serializes the shared file position." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - KSMBD processes attacker-supplied SMB2 QUERY_DIRECTORY requests over TCP port 445, so the vulnerable callback is remotely reachable.\nAC:L - The attacker controls both concurrent requests using the same directory handle and can prolong one enumeration while rapidly completing the other, making the race repeatable.\nPR:N - Although a valid session, tree connection, and readable directory handle are required, ksmbd supports passwordless guest sessions; a guest-readable share therefore permits exploitation without pre-existing privileges.\nUI:N - No victim action is required after the SMB server and accessible share are available.\nS:U - Exploitation compromises the kernel hosting the SMB server without crossing a separate virtualization, sandbox, or IOMMU security authority.\nC:H - The stack use-after-free exposes stale stack, work, search-pattern, and response-buffer pointers, providing a defensible path to high-impact kernel memory disclosure.\nI:H - The callback writes attacker-influenced directory-entry data through a stale d_info pointer and modifies reclaimed stack or response-buffer memory, potentially enabling arbitrary corruption and code execution.\nA:H - Dereferencing or writing through the freed stack and associated stale heap pointers can cause a kernel oops or panic, and the attacker can trigger the race repeatedly over the network." } ] } ], "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", "fs/smb/server/vfs_cache.c", "fs/smb/server/vfs_cache.h" ], "versions": [ { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "1426fd79102539bc0ab5c8fced047ad4313b9908", "status": "affected", "versionType": "git" }, { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "2a64dbf9c739ddf7a25a066507597bf89f8f73d2", "status": "affected", "versionType": "git" }, { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "64dac2d486ec1eb18dc00968b16a230b6b75ec24", "status": "affected", "versionType": "git" }, { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "a1d5d31cad593ea5e1b637f2f39c9ef6d09d1199", "status": "affected", "versionType": "git" }, { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "fd22b039a5a05bc1d6818e9dcd1001fb432a829d", "status": "affected", "versionType": "git" }, { "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9", "lessThan": "be6d26bf27499977c746abc163659915082348d8", "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", "fs/smb/server/vfs_cache.c", "fs/smb/server/vfs_cache.h" ], "versions": [ { "version": "5.15", "status": "affected" }, { "version": "0", "lessThan": "5.15", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.178", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.96", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.39", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.4", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "6.1.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.12.96" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "6.18.39" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.1.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/1426fd79102539bc0ab5c8fced047ad4313b9908" }, { "url": "https://git.kernel.org/stable/c/2a64dbf9c739ddf7a25a066507597bf89f8f73d2" }, { "url": "https://git.kernel.org/stable/c/64dac2d486ec1eb18dc00968b16a230b6b75ec24" }, { "url": "https://git.kernel.org/stable/c/a1d5d31cad593ea5e1b637f2f39c9ef6d09d1199" }, { "url": "https://git.kernel.org/stable/c/fd22b039a5a05bc1d6818e9dcd1001fb432a829d" }, { "url": "https://git.kernel.org/stable/c/be6d26bf27499977c746abc163659915082348d8" } ], "title": "ksmbd: serialize QUERY_DIRECTORY requests per file", "x_generator": { "engine": "bippy-1.2.0" } } } }