ksmbd: fix ipc error and crash

Original patch: cifsd-team/ksmbd-tools#227
adapted for ksmbd kernel module v3.4.3 by me.
Fixes crash in v3.4.3 only. Use original patch when updating to v3.4.4
as this one will fail hunk immortalwrt#1.

Signed-off-by: Marius Dinu <[email protected]>

package/kernel/ksmbd/patches/02-ipc-reserved-memory.patch

@@ -0,0 +1,99 @@
+From 41dbda16a0902798e732abc6599de256b9dc3b27 Mon Sep 17 00:00:00 2001
+From: Namjae Jeon <[email protected]>
+Date: Thu, 6 Jan 2022 10:30:31 +0900
+Subject: ksmbd: add reserved room in ipc request/response
+
+Whenever new parameter is added to smb configuration, It is possible
+to break the execution of the IPC daemon by mismatch size of
+request/response. This patch tries to reserve space in ipc request/response
+in advance to prevent that.
+
+Signed-off-by: Namjae Jeon <[email protected]>
+Signed-off-by: Steve French <[email protected]>
+---
+ fs/ksmbd/ksmbd_netlink.h | 11 ++++++++++-
+ 1 file changed, 10 insertions(+), 1 deletion(-)
+
+--- a/ksmbd_netlink.h
++++ b/ksmbd_netlink.h
+@@ -103,6 +103,7 @@ struct ksmbd_startup_request {
+ 					 * we set the SPARSE_FILES bit (0x40).
+ 					 */
+ 	__u32	sub_auth[3];		/* Subauth value for Security ID */
++	__u32	reserved[128];		/* Reserved room */
+ 	__u32	ifc_list_sz;		/* interfaces list size */
+ 	__s8	____payload[];
+ };
+@@ -113,7 +114,7 @@ struct ksmbd_startup_request {
+  * IPC request to shutdown ksmbd server.
+  */
+ struct ksmbd_shutdown_request {
+-	__s32	reserved;
++	__s32	reserved[16];
+ };
+
+ /*
+@@ -122,6 +123,7 @@ struct ksmbd_shutdown_request {
+ struct ksmbd_login_request {
+ 	__u32	handle;
+ 	__s8	account[KSMBD_REQ_MAX_ACCOUNT_NAME_SZ]; /* user account name */
++	__u32	reserved[16];				/* Reserved room */
+ };
+
+ /*
+@@ -135,6 +137,7 @@ struct ksmbd_login_response {
+ 	__u16	status;
+ 	__u16	hash_sz;			/* hash size */
+ 	__s8	hash[KSMBD_REQ_MAX_HASH_SZ];	/* password hash */
++	__u32	reserved[16];			/* Reserved room */
+ };
+
+ /*
+@@ -143,6 +146,7 @@ struct ksmbd_login_response {
+ struct ksmbd_share_config_request {
+ 	__u32	handle;
+ 	__s8	share_name[KSMBD_REQ_MAX_SHARE_NAME]; /* share name */
++	__u32	reserved[16];		/* Reserved room */
+ };
+
+ /*
+@@ -157,6 +161,7 @@ struct ksmbd_share_config_response {
+ 	__u16	force_directory_mode;
+ 	__u16	force_uid;
+ 	__u16	force_gid;
++	__u32	reserved[128];		/* Reserved room */
+ 	__u32	veto_list_sz;
+ 	__s8	____payload[];
+ };
+@@ -187,6 +192,7 @@ struct ksmbd_tree_connect_request {
+ 	__s8	account[KSMBD_REQ_MAX_ACCOUNT_NAME_SZ];
+ 	__s8	share[KSMBD_REQ_MAX_SHARE_NAME];
+ 	__s8	peer_addr[64];
++	__u32	reserved[16];		/* Reserved room */
+ };
+
+ /*
+@@ -196,6 +202,7 @@ struct ksmbd_tree_connect_response {
+ 	__u32	handle;
+ 	__u16	status;
+ 	__u16	connection_flags;
++	__u32	reserved[16];		/* Reserved room */
+ };
+
+ /*
+@@ -204,6 +211,7 @@ struct ksmbd_tree_connect_response {
+ struct ksmbd_tree_disconnect_request {
+ 	__u64	session_id;	/* session id */
+ 	__u64	connect_id;	/* tree connection id */
++	__u32	reserved[16];	/* Reserved room */
+ };
+
+ /*
+@@ -212,6 +220,7 @@ struct ksmbd_tree_disconnect_request {
+ struct ksmbd_logout_request {
+ 	__s8	account[KSMBD_REQ_MAX_ACCOUNT_NAME_SZ]; /* user account name */
+ 	__u32	account_flags;
++	__u32	reserved[16];				/* Reserved room */
+ };
+
+ /*