KSMBD

Definition

KSMBD (ksmbd) is the in-kernel SMB file server in Linux, distinct from userspace samba. Exposure requires explicit install/start of ksmbd-tools.

Key Points

• 2026-10-21: ZDI-CAN-33774 — protocol dispatch race, CVSS 9.0 pre-auth RCE path; fix commit 68f410faedaf in maintainer tree, not mainline as of Oct 22 (2026-10-22-zdi-lkml-leak-pwnwatch)
• ZDI-CAN-33549 — SMB Direct integer underflow; needs RDMA + writable share

Samba-only file servers are not affected by ksmbd bugs.

Related

• linux-kernel
• zero-day-initiative
• responsible-disclosure

Sources

• 2026-10-22-linux-kernel-vulnerabilities-lkml-leak