{"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"}}}}