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.

A flaw was found in the Linux kernel's ksmbd (kernel Server Message Block daemon) component. Concurrent directory query requests using the same file handle can lead to a stack use-after-free vulnerability. This occurs because smb2_query_dir() stores a pointer to stack-allocated data that can be overwritten by another request while still in use. An attacker could exploit this to cause a denial of service.

Red Hat Enterprise Linux 10 Not affected kernel Red Hat Enterprise Linux 6 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel-rt Red Hat Enterprise Linux 8 Not affected kernel Red Hat Enterprise Linux 8 Not affected kernel-rt Red Hat Enterprise Linux 9 Not affected kernel Red Hat Enterprise Linux 9 Not affected kernel-rt Red Hat Hardened Images Not affected erlang27 https://www.cve.org/CVERecord?id=CVE-2026-64397 https://nvd.nist.gov/vuln/detail/CVE-2026-64397 https://lore.kernel.org/linux-cve-announce/2026072529-CVE-2026-64397-7e0d@gregkh/T