CVE-2026-64016
CriticalCVSS 9.8Exploitation Probability (EPSS)
Low risk36th percentile - higher than 36% of all known CVEs
Summary
In the Linux kernel's ksmbd filesystem, a vulnerability was found in the error path of durable reconnect handling. After a successful reconnect, a cleanup function may free the file object without removing it from the session ID table, leading to a use-after-free condition.
Risk Assessment
This vulnerability could allow a local attacker to trigger kernel memory corruption, potentially causing a system crash or privilege escalation.
Recommendation
Immediately update the Linux kernel to a version containing the fix (commit 0b8d1e2b1f5e or later).
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix durable reconnect error path file lifetime After a durable reconnect succeeds, ksmbd_reopen_durable_fd() republishes the same ksmbd_file into the session volatile-id table. If smb2_open() then takes a later error path, cleanup first calls ksmbd_fd_put(work, fp) and then unconditionally calls ksmbd_put_durable_fd(dh_info.fp). In this case fp and dh_info.fp are the same object. The first put drops the reconnect lookup reference, but the final durable put can run __ksmbd_close_fd(NULL, fp). Because the final close is not session-aware, it can free the file object without removing the volatile-id entry that was just published into the session table. Use the session-aware put for the final reconnect drop when the reconnect had already succeeded and the error path is cleaning up the republished file. Earlier reconnect failures, before fp is assigned to dh_info.fp, keep using the durable-only put path.