ksmbd: add channel rwlock

Add missing rwlock for channel list in session.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Reviewed-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/ksmbd/mgmt/user_session.c

@@ -32,11 +32,13 @@ static void free_channel_list(struct ksmbd_session *sess)
 {
 	struct channel *chann, *tmp;
 
+	write_lock(&sess->chann_lock);
 	list_for_each_entry_safe(chann, tmp, &sess->ksmbd_chann_list,
 				 chann_list) {
 		list_del(&chann->chann_list);
 		kfree(chann);
 	}
+	write_unlock(&sess->chann_lock);
 }
 
 static void __session_rpc_close(struct ksmbd_session *sess,
@@ -303,6 +305,7 @@ static struct ksmbd_session *__session_create(int protocol)
 	INIT_LIST_HEAD(&sess->rpc_handle_list);
 	sess->sequence_number = 1;
 	atomic_set(&sess->refcnt, 1);
+	rwlock_init(&sess->chann_lock);
 
 	switch (protocol) {
 	case CIFDS_SESSION_FLAG_SMB2:

fs/ksmbd/mgmt/user_session.h

@@ -48,6 +48,7 @@ struct ksmbd_session {
 	char				sess_key[CIFS_KEY_SIZE];
 
 	struct hlist_node		hlist;
+	rwlock_t			chann_lock;
 	struct list_head		ksmbd_chann_list;
 	struct xarray			tree_conns;
 	struct ida			tree_conn_ida;

fs/ksmbd/smb2pdu.c

@@ -1512,15 +1512,19 @@ static int ntlm_authenticate(struct ksmbd_work *work)
 
 binding_session:
 	if (conn->dialect >= SMB30_PROT_ID) {
+		read_lock(&sess->chann_lock);
 		chann = lookup_chann_list(sess, conn);
+		read_unlock(&sess->chann_lock);
 		if (!chann) {
 			chann = kmalloc(sizeof(struct channel), GFP_KERNEL);
 			if (!chann)
 				return -ENOMEM;
 
 			chann->conn = conn;
 			INIT_LIST_HEAD(&chann->chann_list);
+			write_lock(&sess->chann_lock);
 			list_add(&chann->chann_list, &sess->ksmbd_chann_list);
+			write_unlock(&sess->chann_lock);
 		}
 	}
 
@@ -1594,15 +1598,19 @@ static int krb5_authenticate(struct ksmbd_work *work)
 	}
 
 	if (conn->dialect >= SMB30_PROT_ID) {
+		read_lock(&sess->chann_lock);
 		chann = lookup_chann_list(sess, conn);
+		read_unlock(&sess->chann_lock);
 		if (!chann) {
 			chann = kmalloc(sizeof(struct channel), GFP_KERNEL);
 			if (!chann)
 				return -ENOMEM;
 
 			chann->conn = conn;
 			INIT_LIST_HEAD(&chann->chann_list);
+			write_lock(&sess->chann_lock);
 			list_add(&chann->chann_list, &sess->ksmbd_chann_list);
+			write_unlock(&sess->chann_lock);
 		}
 	}
 
@@ -8361,10 +8369,14 @@ int smb3_check_sign_req(struct ksmbd_work *work)
 	if (le16_to_cpu(hdr->Command) == SMB2_SESSION_SETUP_HE) {
 		signing_key = work->sess->smb3signingkey;
 	} else {
+		read_lock(&work->sess->chann_lock);
 		chann = lookup_chann_list(work->sess, conn);
-		if (!chann)
+		if (!chann) {
+			read_unlock(&work->sess->chann_lock);
 			return 0;
+		}
 		signing_key = chann->smb3signingkey;
+		read_unlock(&work->sess->chann_lock);
 	}
 
 	if (!signing_key) {
@@ -8424,10 +8436,14 @@ void smb3_set_sign_rsp(struct ksmbd_work *work)
 	    le16_to_cpu(hdr->Command) == SMB2_SESSION_SETUP_HE) {
 		signing_key = work->sess->smb3signingkey;
 	} else {
+		read_lock(&work->sess->chann_lock);
 		chann = lookup_chann_list(work->sess, work->conn);
-		if (!chann)
+		if (!chann) {
+			read_unlock(&work->sess->chann_lock);
 			return;
+		}
 		signing_key = chann->smb3signingkey;
+		read_unlock(&work->sess->chann_lock);
 	}
 
 	if (!signing_key)