CVE-2026-64397

Summary

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: serialize QUERY_DIRECTORY requests per file

smb2_query_dir() stores a pointer to its stack-allocated private data in the ksmbd_file readdir_data. Concurrent QUERY_DIRECTORY requests using the same file handle can overwrite this pointer while an iterate_dir() callback is still using it, resulting in a stack use-after-free.

Add a per-file mutex and hold it while accessing the shared directory enumeration state. The lock covers scan restart, dot entry state, readdir_data setup and iteration, and response construction. This prevents another request from replacing readdir_data.private before the current request has finished using it and also serializes the shared file position.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxe2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 1426fd79102539bc0ab5c8fced047ad4313b9908affected
LinuxLinuxe2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 2a64dbf9c739ddf7a25a066507597bf89f8f73d2affected
LinuxLinuxe2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 64dac2d486ec1eb18dc00968b16a230b6b75ec24affected
LinuxLinuxe2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < a1d5d31cad593ea5e1b637f2f39c9ef6d09d1199affected
LinuxLinuxe2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < fd22b039a5a05bc1d6818e9dcd1001fb432a829daffected
LinuxLinuxe2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < be6d26bf27499977c746abc163659915082348d8affected
LinuxLinux5.15affected
LinuxLinux0 < 5.15unaffected
LinuxLinux6.1.178 <= 6.1.*unaffected
LinuxLinux6.6.145 <= 6.6.*unaffected
LinuxLinux6.12.96 <= 6.12.*unaffected
LinuxLinux6.18.39 <= 6.18.*unaffected
LinuxLinux7.1.4 <= 7.1.*unaffected
LinuxLinux7.2-rc1 <= *unaffected

Weaknesses

References