x86/kprobes: Fix crash when probing CS CALL instructionsgrafted

When using eBPF to probe CS CALL instructions within a function,
a crash can be triggered.

The eBPF tool probes offset 257 of the __hrtimer_run_queues()
function:

<__hrtimer_run_queues+249>:  nopl   0x0(%rax,%rax,1)
<__hrtimer_run_queues+254>:  mov    %r14,%rdi
<__hrtimer_run_queues+257>:  cs call <__x86_indirect_thunk_r12>
<__hrtimer_run_queues+263>:  mov    %eax,%r12d
<__hrtimer_run_queues+266>:  xchg   %ax,%ax
<__hrtimer_run_queues+268>:  mov    %r13,%rdi

Which triggers this crash:

  BUG: unable to handle page fault for address: 00000000000f41c9
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  PGD 0 P4D 0
  Oops: 0002 [#1] SMP NOPTI
  CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P
  RIP: 0010:__hrtimer_run_queues+0x106/0x230

Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is
at the 6th byte of the above CS CALL instruction. Since the CS CALL
instruction occupies 6 bytes, the exception occurred in the middle of that
call instruction.

The root cause is that when using eBPF tools to probe in the middle of a
function, a kprobe with INT3 is used as the underlying implementation.

During single-step emulation of the original CALL instruction,
int3_emulate_call() assumes that the probed CALL instruction is 5 bytes
long. However, the actual CS-prefixed CALL instruction occupies 6 bytes,
so it constructs an incorrect exception return address. When the CPU
returns from the kprobe handler, the next instruction to be executed is at
the address of the last byte of that CS CALL instruction. Coincidentally,
starting from that address, the CPU fetches and decodes a completely
different instruction, which ultimately triggers a kernel crash.

Fix the issue by using the actual instruction length obtained from
the instruction decoder when constructing the exception return
address, rather than relying on the hardcoded CALL_INSN_SIZE macro.

[ mingo: Refined the changelog ]

Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jinke Han <jinkehan@didiglobal.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000

1 files changed, 760 insertions, 0 deletions

diff --git a/fs/smb/server/server.c b/fs/smb/server/server.c
new file mode 100644
index 000000000..0069d4e6a
--- /dev/null
+++ b/fs/smb/server/server.c
@@ -0,0 +1,760 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *   Copyright (C) 2016 Namjae Jeon <linkinjeon@kernel.org>
+ *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
+ */
+
+#include "glob.h"
+#include "oplock.h"
+#include "misc.h"
+#include <linux/sched/signal.h>
+#include <linux/workqueue.h>
+#include <linux/sysfs.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+
+#include "server.h"
+#include "smb_common.h"
+#include "smb2pdu.h"
+#include "../common/smb2status.h"
+#include "connection.h"
+#include "transport_ipc.h"
+#include "mgmt/user_session.h"
+#include "crypto_ctx.h"
+#include "auth.h"
+#include "stats.h"
+#include "compress.h"
+#include "mgmt/share_config.h"
+#include "mgmt/tree_connect.h"
+
+int ksmbd_debug_types;
+
+struct ksmbd_server_config server_conf;
+
+enum SERVER_CTRL_TYPE {
+	SERVER_CTRL_TYPE_INIT,
+	SERVER_CTRL_TYPE_RESET,
+};
+
+struct server_ctrl_struct {
+	int			type;
+	struct work_struct	ctrl_work;
+};
+
+static DEFINE_MUTEX(ctrl_lock);
+
+static int ___server_conf_set(int idx, char *val)
+{
+	if (idx >= ARRAY_SIZE(server_conf.conf))
+		return -EINVAL;
+
+	if (!val || val[0] == 0x00)
+		return -EINVAL;
+
+	kfree(server_conf.conf[idx]);
+	server_conf.conf[idx] = kstrdup(val, KSMBD_DEFAULT_GFP);
+	if (!server_conf.conf[idx])
+		return -ENOMEM;
+	return 0;
+}
+
+int ksmbd_set_netbios_name(char *v)
+{
+	return ___server_conf_set(SERVER_CONF_NETBIOS_NAME, v);
+}
+
+int ksmbd_set_server_string(char *v)
+{
+	return ___server_conf_set(SERVER_CONF_SERVER_STRING, v);
+}
+
+int ksmbd_set_work_group(char *v)
+{
+	return ___server_conf_set(SERVER_CONF_WORK_GROUP, v);
+}
+
+char *ksmbd_netbios_name(void)
+{
+	return server_conf.conf[SERVER_CONF_NETBIOS_NAME];
+}
+
+char *ksmbd_server_string(void)
+{
+	return server_conf.conf[SERVER_CONF_SERVER_STRING];
+}
+
+char *ksmbd_work_group(void)
+{
+	return server_conf.conf[SERVER_CONF_WORK_GROUP];
+}
+
+/**
+ * check_conn_state() - check state of server thread connection
+ * @work:     smb work containing server thread information
+ *
+ * Return:	0 on valid connection, otherwise 1 to reconnect
+ */
+static inline int check_conn_state(struct ksmbd_work *work)
+{
+	struct smb_hdr *rsp_hdr;
+
+	if (ksmbd_conn_exiting(work->conn) ||
+	    ksmbd_conn_need_reconnect(work->conn)) {
+		rsp_hdr = smb_get_msg(work->response_buf);
+		rsp_hdr->Status.CifsError = STATUS_CONNECTION_DISCONNECTED;
+		return 1;
+	}
+	return 0;
+}
+
+#define SERVER_HANDLER_CONTINUE		0
+#define SERVER_HANDLER_ABORT		1
+
+static int __process_request(struct ksmbd_work *work, struct ksmbd_conn *conn,
+			     u16 *cmd)
+{
+	struct smb_version_cmds *cmds;
+	u16 command;
+	bool signed_req;
+	int ret;
+
+	if (check_conn_state(work))
+		return SERVER_HANDLER_CONTINUE;
+
+	if (ksmbd_verify_smb_message(work)) {
+		conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER);
+		return SERVER_HANDLER_ABORT;
+	}
+
+	command = conn->ops->get_cmd_val(work);
+	*cmd = command;
+
+andx_again:
+	if (command >= conn->max_cmds) {
+		conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER);
+		return SERVER_HANDLER_ABORT;
+	}
+
+	cmds = &conn->cmds[command];
+	if (!cmds->proc) {
+		ksmbd_debug(SMB, "*** not implemented yet cmd = %x\n", command);
+		conn->ops->set_rsp_status(work, STATUS_NOT_IMPLEMENTED);
+		return SERVER_HANDLER_ABORT;
+	}
+
+	signed_req = conn->ops->is_sign_req && conn->ops->is_sign_req(work, command);
+	if (work->sess && work->sess->sign && !work->encrypted &&
+	    !signed_req) {
+		conn->ops->set_rsp_status(work, STATUS_ACCESS_DENIED);
+		return SERVER_HANDLER_ABORT;
+	}
+
+	if (work->sess && signed_req) {
+		ret = conn->ops->check_sign_req(work);
+		if (!ret) {
+			conn->ops->set_rsp_status(work, STATUS_ACCESS_DENIED);
+			return SERVER_HANDLER_ABORT;
+		}
+	}
+
+	ret = cmds->proc(work);
+	if (conn->ops->inc_reqs) {
+		struct smb2_hdr *rsp = ksmbd_resp_buf_curr(work);
+
+		conn->ops->inc_reqs(command, rsp->Status);
+	}
+
+	if (ret < 0)
+		ksmbd_debug(CONN, "Failed to process %u [%d]\n", command, ret);
+	/* AndX commands - chained request can return positive values */
+	else if (ret > 0) {
+		command = ret;
+		*cmd = command;
+		goto andx_again;
+	}
+
+	if (work->send_no_response)
+		return SERVER_HANDLER_ABORT;
+	return SERVER_HANDLER_CONTINUE;
+}
+
+static void __handle_ksmbd_work(struct ksmbd_work *work,
+				struct ksmbd_conn *conn)
+{
+	u16 command = 0;
+	int rc;
+	bool is_chained = false;
+
+	if (conn->ops->is_transform_hdr &&
+	    conn->ops->is_transform_hdr(work->request_buf)) {
+		rc = conn->ops->decrypt_req(work);
+		if (rc < 0) {
+			ksmbd_conn_abort(conn);
+			return;
+		}
+		work->encrypted = true;
+
+		/*
+		 * SMB3 applies compression before encryption.  The receive loop
+		 * handles a plain compression transform before allocating work, but
+		 * an encrypted request exposes that transform only after decryption.
+		 */
+		if (((struct smb2_hdr *)smb_get_msg(work->request_buf))->ProtocolId ==
+		    SMB2_COMPRESSION_TRANSFORM_ID) {
+			rc = ksmbd_decompress_work_request(work);
+			if (rc < 0) {
+				ksmbd_conn_abort(conn);
+				return;
+			}
+		}
+
+		/* The decrypted payload must now be a complete SMB2 request. */
+		if (((struct smb2_hdr *)smb_get_msg(work->request_buf))->ProtocolId !=
+			SMB2_PROTO_NUMBER ||
+		    get_rfc1002_len(work->request_buf) < sizeof(struct smb2_pdu)) {
+			ksmbd_conn_abort(conn);
+			return;
+		}
+	}
+
+	if (conn->ops->allocate_rsp_buf(work))
+		return;
+
+	rc = conn->ops->init_rsp_hdr(work);
+	if (rc) {
+		/* either uid or tid is not correct */
+		conn->ops->set_rsp_status(work, STATUS_INVALID_HANDLE);
+		goto send;
+	}
+
+	do {
+		if (conn->ops->check_user_session) {
+			rc = conn->ops->check_user_session(work);
+			if (rc < 0) {
+				if (rc == -EINVAL)
+					conn->ops->set_rsp_status(work,
+						STATUS_INVALID_PARAMETER);
+				else if (rc == -EKEYEXPIRED)
+					conn->ops->set_rsp_status(work,
+						STATUS_NETWORK_SESSION_EXPIRED);
+				else
+					conn->ops->set_rsp_status(work,
+						STATUS_USER_SESSION_DELETED);
+				if (conn->ops->is_sign_req(work, conn->ops->get_cmd_val(work))) {
+					struct smb2_hdr *rsp_hdr;
+
+					rsp_hdr = ksmbd_resp_buf_curr(work);
+					if (rc == -EKEYEXPIRED && work->sess &&
+					    conn->ops->set_sign_rsp)
+						conn->ops->set_sign_rsp(work);
+					else
+						rsp_hdr->Flags |= SMB2_FLAGS_SIGNED;
+				}
+				goto send;
+			} else if (rc > 0) {
+				rc = conn->ops->get_ksmbd_tcon(work);
+				if (rc < 0) {
+					if (rc == -EINVAL)
+						conn->ops->set_rsp_status(work,
+							STATUS_INVALID_PARAMETER);
+					else
+						conn->ops->set_rsp_status(work,
+							STATUS_NETWORK_NAME_DELETED);
+					goto send;
+				}
+
+				if (work->tcon &&
+				    test_share_config_flag(work->tcon->share_conf,
+							   KSMBD_SHARE_FLAG_ENCRYPT_DATA) &&
+				    !work->encrypted) {
+					conn->ops->set_rsp_status(work,
+								  STATUS_ACCESS_DENIED);
+					goto send;
+				}
+			}
+		}
+
+		rc = __process_request(work, conn, &command);
+		if (rc == SERVER_HANDLER_ABORT) {
+			smb2_complete_request_open(work);
+			break;
+		}
+
+		/*
+		 * Call smb2_set_rsp_credits() function to set number of credits
+		 * granted in hdr of smb2 response.
+		 */
+		if (conn->ops->set_rsp_credits) {
+			spin_lock(&conn->credits_lock);
+			rc = conn->ops->set_rsp_credits(work);
+			spin_unlock(&conn->credits_lock);
+			if (rc < 0) {
+				conn->ops->set_rsp_status(work,
+					STATUS_INVALID_PARAMETER);
+				smb2_complete_request_open(work);
+				goto send;
+			}
+		}
+
+		smb2_complete_request_open(work);
+
+		is_chained = is_chained_smb2_message(work);
+
+		if (work->sess &&
+		    (work->sess->sign || smb3_11_final_sess_setup_resp(work) ||
+		     conn->ops->is_sign_req(work, command))) {
+			if (command == SMB2_SESSION_SETUP_HE &&
+			    work->sess->dialect >= SMB30_PROT_ID &&
+			    conn->dialect < SMB30_PROT_ID)
+				smb3_set_sign_rsp(work);
+			else
+				conn->ops->set_sign_rsp(work);
+		}
+	} while (is_chained == true);
+
+send:
+	smb2_complete_request_open(work);
+	/*
+	 * Release any credit charge still outstanding for this request.  On
+	 * the normal path smb2_set_rsp_credits() already returned it, but the
+	 * abort, error and send-no-response paths skip that call, so the
+	 * charge would otherwise leak and eventually exhaust the connection's
+	 * outstanding credit window.
+	 */
+	if (work->credit_charge) {
+		spin_lock(&conn->credits_lock);
+		conn->outstanding_credits -= work->credit_charge;
+		work->credit_charge = 0;
+		spin_unlock(&conn->credits_lock);
+	}
+
+	if (work->tcon)
+		ksmbd_tree_connect_put(work->tcon);
+	smb3_preauth_hash_rsp(work);
+	/*
+	 * Preauthentication hashes cover the original SMB2 response. Apply the
+	 * transport compression wrapper only after updating the hash.
+	 */
+	if (work->compress_response) {
+		rc = ksmbd_compress_response(work);
+		if (rc < 0)
+			ksmbd_debug(CONN, "Failed to compress response: %d\n", rc);
+	}
+	if (work->sess && work->sess->enc && work->encrypted &&
+	    conn->ops->encrypt_resp) {
+		rc = conn->ops->encrypt_resp(work);
+		if (rc < 0)
+			conn->ops->set_rsp_status(work, STATUS_DATA_ERROR);
+	}
+	if (work->sess)
+		ksmbd_user_session_put(work->sess);
+
+	ksmbd_conn_write(work);
+}
+
+/**
+ * handle_ksmbd_work() - process pending smb work requests
+ * @wk:	smb work containing request command buffer
+ *
+ * called by kworker threads to processing remaining smb work requests
+ */
+static void handle_ksmbd_work(struct work_struct *wk)
+{
+	struct ksmbd_work *work = container_of(wk, struct ksmbd_work, work);
+	struct ksmbd_conn *conn = work->conn;
+
+	atomic64_inc(&conn->stats.request_served);
+
+	__handle_ksmbd_work(work, conn);
+
+	ksmbd_conn_try_dequeue_request(work);
+	ksmbd_free_work_struct(work);
+	ksmbd_conn_r_count_dec(conn);
+}
+
+/**
+ * queue_ksmbd_work() - queue a smb request to worker thread queue
+ *		for processing smb command and sending response
+ * @conn:	connection instance
+ *
+ * read remaining data from socket create and submit work.
+ */
+static int queue_ksmbd_work(struct ksmbd_conn *conn)
+{
+	struct ksmbd_work *work;
+	int err;
+
+	err = ksmbd_init_smb_server(conn);
+	if (err)
+		return 0;
+
+	work = ksmbd_alloc_work_struct();
+	if (!work) {
+		pr_err("allocation for work failed\n");
+		return -ENOMEM;
+	}
+
+	work->conn = conn;
+	work->request_buf = conn->request_buf;
+	conn->request_buf = NULL;
+
+	ksmbd_conn_enqueue_request(work);
+	ksmbd_conn_r_count_inc(conn);
+	/* update activity on connection */
+	conn->last_active = jiffies;
+	INIT_WORK(&work->work, handle_ksmbd_work);
+	ksmbd_queue_work(work);
+	return 0;
+}
+
+static int ksmbd_server_process_request(struct ksmbd_conn *conn)
+{
+	return queue_ksmbd_work(conn);
+}
+
+static int ksmbd_server_terminate_conn(struct ksmbd_conn *conn)
+{
+	ksmbd_sessions_deregister(conn);
+	destroy_lease_table(conn);
+	return 0;
+}
+
+static void ksmbd_server_tcp_callbacks_init(void)
+{
+	struct ksmbd_conn_ops ops;
+
+	ops.process_fn = ksmbd_server_process_request;
+	ops.terminate_fn = ksmbd_server_terminate_conn;
+
+	ksmbd_conn_init_server_callbacks(&ops);
+}
+
+static void server_conf_free(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(server_conf.conf); i++) {
+		kfree(server_conf.conf[i]);
+		server_conf.conf[i] = NULL;
+	}
+}
+
+static int server_conf_init(void)
+{
+	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
+	server_conf.enforced_signing = 0;
+	server_conf.min_protocol = ksmbd_min_protocol();
+	server_conf.max_protocol = ksmbd_max_protocol();
+	server_conf.auth_mechs = KSMBD_AUTH_NTLMSSP;
+#ifdef CONFIG_SMB_SERVER_KERBEROS5
+	server_conf.auth_mechs |= KSMBD_AUTH_KRB5 |
+				KSMBD_AUTH_MSKRB5;
+#endif
+	server_conf.max_inflight_req = SMB2_MAX_CREDITS;
+	return 0;
+}
+
+static void server_ctrl_handle_init(struct server_ctrl_struct *ctrl)
+{
+	int ret;
+
+	ksmbd_proc_reset();
+	ret = ksmbd_conn_transport_init();
+	if (ret) {
+		server_queue_ctrl_reset_work();
+		return;
+	}
+
+	pr_info("running\n");
+	WRITE_ONCE(server_conf.state, SERVER_STATE_RUNNING);
+}
+
+static void server_ctrl_handle_reset(struct server_ctrl_struct *ctrl)
+{
+	ksmbd_ipc_soft_reset();
+	ksmbd_conn_transport_destroy();
+	ksmbd_stop_durable_scavenger();
+	server_conf_free();
+	server_conf_init();
+	WRITE_ONCE(server_conf.state, SERVER_STATE_STARTING_UP);
+}
+
+static void server_ctrl_handle_work(struct work_struct *work)
+{
+	struct server_ctrl_struct *ctrl;
+
+	ctrl = container_of(work, struct server_ctrl_struct, ctrl_work);
+
+	mutex_lock(&ctrl_lock);
+	switch (ctrl->type) {
+	case SERVER_CTRL_TYPE_INIT:
+		server_ctrl_handle_init(ctrl);
+		break;
+	case SERVER_CTRL_TYPE_RESET:
+		server_ctrl_handle_reset(ctrl);
+		break;
+	default:
+		pr_err("Unknown server work type: %d\n", ctrl->type);
+	}
+	mutex_unlock(&ctrl_lock);
+	kfree(ctrl);
+	module_put(THIS_MODULE);
+}
+
+static int __queue_ctrl_work(int type)
+{
+	struct server_ctrl_struct *ctrl;
+
+	ctrl = kmalloc_obj(struct server_ctrl_struct, KSMBD_DEFAULT_GFP);
+	if (!ctrl)
+		return -ENOMEM;
+
+	__module_get(THIS_MODULE);
+	ctrl->type = type;
+	INIT_WORK(&ctrl->ctrl_work, server_ctrl_handle_work);
+	queue_work(system_long_wq, &ctrl->ctrl_work);
+	return 0;
+}
+
+int server_queue_ctrl_init_work(void)
+{
+	return __queue_ctrl_work(SERVER_CTRL_TYPE_INIT);
+}
+
+int server_queue_ctrl_reset_work(void)
+{
+	return __queue_ctrl_work(SERVER_CTRL_TYPE_RESET);
+}
+
+static ssize_t stats_show(const struct class *class, const struct class_attribute *attr,
+			  char *buf)
+{
+	/*
+	 * Inc this each time you change stats output format,
+	 * so user space will know what to do.
+	 */
+	static int stats_version = 2;
+	static const char * const state[] = {
+		"startup",
+		"running",
+		"reset",
+		"shutdown"
+	};
+	return sysfs_emit(buf, "%d %s %d %lu\n", stats_version,
+			  state[server_conf.state], server_conf.tcp_port,
+			  server_conf.ipc_last_active / HZ);
+}
+
+static ssize_t kill_server_store(const struct class *class,
+				 const struct class_attribute *attr, const char *buf,
+				 size_t len)
+{
+	if (!sysfs_streq(buf, "hard"))
+		return len;
+
+	pr_info("kill command received\n");
+	mutex_lock(&ctrl_lock);
+	WRITE_ONCE(server_conf.state, SERVER_STATE_RESETTING);
+	__module_get(THIS_MODULE);
+	server_ctrl_handle_reset(NULL);
+	module_put(THIS_MODULE);
+	mutex_unlock(&ctrl_lock);
+	return len;
+}
+
+static const char * const debug_type_strings[] = {"smb", "auth", "vfs",
+						  "oplock", "ipc", "conn",
+						  "rdma"};
+
+static ssize_t debug_show(const struct class *class, const struct class_attribute *attr,
+			  char *buf)
+{
+	ssize_t sz = 0;
+	int i, pos = 0;
+
+	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
+		if ((ksmbd_debug_types >> i) & 1) {
+			pos = sysfs_emit_at(buf, sz, "[%s] ", debug_type_strings[i]);
+		} else {
+			pos = sysfs_emit_at(buf, sz, "%s ", debug_type_strings[i]);
+		}
+		sz += pos;
+	}
+	sz += sysfs_emit_at(buf, sz, "\n");
+	return sz;
+}
+
+static ssize_t debug_store(const struct class *class, const struct class_attribute *attr,
+			   const char *buf, size_t len)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(debug_type_strings); i++) {
+		if (sysfs_streq(buf, "all")) {
+			if (ksmbd_debug_types == KSMBD_DEBUG_ALL)
+				ksmbd_debug_types = 0;
+			else
+				ksmbd_debug_types = KSMBD_DEBUG_ALL;
+			break;
+		}
+
+		if (sysfs_streq(buf, debug_type_strings[i])) {
+			if (ksmbd_debug_types & (1 << i))
+				ksmbd_debug_types &= ~(1 << i);
+			else
+				ksmbd_debug_types |= (1 << i);
+			break;
+		}
+	}
+
+	return len;
+}
+
+static CLASS_ATTR_RO(stats);
+static CLASS_ATTR_WO(kill_server);
+static CLASS_ATTR_RW(debug);
+
+static struct attribute *ksmbd_control_class_attrs[] = {
+	&class_attr_stats.attr,
+	&class_attr_kill_server.attr,
+	&class_attr_debug.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(ksmbd_control_class);
+
+static struct class ksmbd_control_class = {
+	.name		= "ksmbd-control",
+	.class_groups	= ksmbd_control_class_groups,
+};
+
+static int ksmbd_server_shutdown(void)
+{
+	WRITE_ONCE(server_conf.state, SERVER_STATE_SHUTTING_DOWN);
+
+	class_unregister(&ksmbd_control_class);
+	ksmbd_workqueue_destroy();
+	ksmbd_ipc_release();
+	ksmbd_conn_transport_destroy();
+	/*
+	 * ksmbd_conn_transport_destroy() calls delete_proc_clients() and destroys
+	 * sessions. ksmbd_session_destroy() removes each session's proc entry.
+	 * Keep the procfs tree alive until these entries have been removed.
+	 */
+	ksmbd_proc_cleanup();
+	ksmbd_crypto_destroy();
+	ksmbd_free_global_file_table();
+	destroy_lease_table(NULL);
+	ksmbd_work_pool_destroy();
+	ksmbd_exit_file_cache();
+	server_conf_free();
+	return 0;
+}
+
+static int __init ksmbd_server_init(void)
+{
+	int ret;
+
+	ret = class_register(&ksmbd_control_class);
+	if (ret) {
+		pr_err("Unable to register ksmbd-control class\n");
+		return ret;
+	}
+
+	ret = ksmbd_proc_init();
+	if (ret)
+		goto err_unregister;
+
+	if (create_proc_sessions())
+		pr_warn("Unable to create sessions procfs entry\n");
+
+	if (create_proc_shares())
+		pr_warn("Unable to create shares procfs entry\n");
+
+	ksmbd_server_tcp_callbacks_init();
+
+	ret = server_conf_init();
+	if (ret)
+		goto err_proc_cleanup;
+
+	ret = ksmbd_work_pool_init();
+	if (ret)
+		goto err_proc_cleanup;
+
+	ret = ksmbd_init_file_cache();
+	if (ret)
+		goto err_destroy_work_pools;
+
+	ret = ksmbd_ipc_init();
+	if (ret)
+		goto err_exit_file_cache;
+
+	ret = ksmbd_init_global_file_table();
+	if (ret)
+		goto err_ipc_release;
+
+	ret = ksmbd_inode_hash_init();
+	if (ret)
+		goto err_destroy_file_table;
+
+	ret = ksmbd_crypto_create();
+	if (ret)
+		goto err_release_inode_hash;
+
+	ret = ksmbd_workqueue_init();
+	if (ret)
+		goto err_crypto_destroy;
+
+	ret = ksmbd_conn_wq_init();
+	if (ret)
+		goto err_workqueue_destroy;
+
+	return 0;
+
+err_workqueue_destroy:
+	ksmbd_workqueue_destroy();
+err_crypto_destroy:
+	ksmbd_crypto_destroy();
+err_release_inode_hash:
+	ksmbd_release_inode_hash();
+err_destroy_file_table:
+	ksmbd_free_global_file_table();
+err_ipc_release:
+	ksmbd_ipc_release();
+err_exit_file_cache:
+	ksmbd_exit_file_cache();
+err_destroy_work_pools:
+	ksmbd_work_pool_destroy();
+err_proc_cleanup:
+	ksmbd_proc_cleanup();
+err_unregister:
+	class_unregister(&ksmbd_control_class);
+
+	return ret;
+}
+
+/**
+ * ksmbd_server_exit() - shutdown forker thread and free memory at module exit
+ */
+static void __exit ksmbd_server_exit(void)
+{
+	ksmbd_server_shutdown();
+	rcu_barrier();
+	/*
+	 * ksmbd_conn_put() defers the final release onto ksmbd_conn_wq,
+	 * so drain it after rcu_barrier() has fired any pending RCU
+	 * callbacks that may have queued a release.
+	 */
+	ksmbd_conn_wq_destroy();
+	ksmbd_release_inode_hash();
+}
+
+MODULE_AUTHOR("Namjae Jeon <linkinjeon@kernel.org>");
+MODULE_DESCRIPTION("Linux kernel CIFS/SMB SERVER");
+MODULE_LICENSE("GPL");
+MODULE_SOFTDEP("pre: nls");
+MODULE_SOFTDEP("pre: aes");
+MODULE_SOFTDEP("pre: aead2");
+MODULE_SOFTDEP("pre: ccm");
+MODULE_SOFTDEP("pre: gcm");
+module_init(ksmbd_server_init)
+module_exit(ksmbd_server_exit)