Revert "ksmbd: Fix to handle removal of rfc1002 header from smb_hdr"
PATCH 1/1 Revert "ksmbd: Fix to handle removal of rfc1002 header from smb_hdr"
Commit 29dbb4e29e1f ("ksmbd: Fix to handle removal of rfc1002 header from smb_hdr") is a backport of upstream commit 0a70cac78967.
The upstream commit depends on SMB1 header refactoring which removed the RFC1002 length field from struct smb_hdr. Those prerequisite changes are not present in the 6.18.y stable tree, where ksmbd still defines struct smb_hdr with the smb_buf_length field.
As a result, smb_get_msg() advances the buffer by four bytes before it is cast to a structure that already includes the RFC1002 field. This causes a four-byte offset mismatch while parsing and constructing the initial SMB1 multi-protocol negotiate response.
Windows clients then receive a malformed negotiate response and abort the connection.
This reverts commit 29dbb4e29e1f ("ksmbd: Fix to handle removal of rfc1002 header from smb_hdr").
--- fs/smb/server/server.c | 2 +- fs/smb/server/smb_common.c | 20 ++++++++++---------- 2 files changed, 11 insertions(+), 11 deletions(-)
fs/smb/server/server.c +1 -1
@@ -95,7 +95,7 @@ static inline int check_conn_state(struct ksmbd_work *work)if (ksmbd_conn_exiting (work->conn) ||ksmbd_conn_need_reconnect (work->conn)) { - rsp_hdr =smb_get_msg (work->response_buf); + rsp_hdr = work->response_buf; rsp_hdr->Status.CifsError =STATUS_CONNECTION_DISCONNECTED ;return 1 ; }
fs/smb/server/smb_common.c +10 -10
@@ -140,7 +140,7 @@ int ksmbd_verify_smb_message(struct ksmbd_work *work)if (smb2_hdr->ProtocolId ==SMB2_PROTO_NUMBER )return ksmbd_smb2_check_message (work); - hdr =smb_get_msg (work->request_buf); + hdr = work->request_buf;if (*(__le32 *)hdr->Protocol ==SMB1_PROTO_NUMBER && hdr->Command ==SMB_COM_NEGOTIATE ) { work->conn->outstanding_credits++;
@@ -278,14 +278,15 @@ static int ksmbd_negotiate_smb_dialect(void *buf) req->DialectCount); } + proto = *(__le32 *)((struct smb_hdr *)buf)->Protocol;if (proto ==SMB1_PROTO_NUMBER ) {struct smb_negotiate_req *req; - req = (struct smb_negotiate_req *)smb_get_msg (buf); + req = (struct smb_negotiate_req *)buf;if (le16_to_cpu (req->ByteCount) <2 ) goto err_out; -if (offsetof(struct smb_negotiate_req , DialectsArray) + +if (offsetof(struct smb_negotiate_req , DialectsArray) -4 +le16_to_cpu (req->ByteCount) > smb_buf_length) { goto err_out; }
@@ -319,8 +320,8 @@ static u16 get_smb1_cmd_val(struct ksmbd_work *work)*/ static int init_smb1_rsp_hdr (struct ksmbd_work *work) { -struct smb_hdr *rsp_hdr = (struct smb_hdr *)smb_get_msg (work->response_buf); -struct smb_hdr *rcv_hdr = (struct smb_hdr *)smb_get_msg (work->request_buf); +struct smb_hdr *rsp_hdr = (struct smb_hdr *)work->response_buf; +struct smb_hdr *rcv_hdr = (struct smb_hdr *)work->request_buf; rsp_hdr->Command =SMB_COM_NEGOTIATE ; *(__le32 *)rsp_hdr->Protocol =SMB1_PROTO_NUMBER ;
@@ -411,10 +412,9 @@ static int init_smb1_server(struct ksmbd_conn *conn)int ksmbd_init_smb_server (struct ksmbd_conn *conn) { -struct smb_hdr *rcv_hdr = (struct smb_hdr *)smb_get_msg (conn->request_buf);__le32 proto; - proto = *(__le32 *)rcv_hdr->Protocol; + proto = *(__le32 *)((struct smb_hdr *)conn->request_buf)->Protocol;if (conn->need_neg == false) {if (proto ==SMB1_PROTO_NUMBER )return -EINVAL ;
@@ -572,12 +572,12 @@ static int __smb2_negotiate(struct ksmbd_conn *conn)static int smb_handle_negotiate (struct ksmbd_work *work) { -struct smb_negotiate_rsp *neg_rsp =smb_get_msg (work->response_buf); +struct smb_negotiate_rsp *neg_rsp = work->response_buf;ksmbd_debug (SMB ,"Unsupported SMB1 protocol\n" ); -if (ksmbd_iov_pin_rsp (work, (void *)neg_rsp, -sizeof (struct smb_negotiate_rsp ))) +if (ksmbd_iov_pin_rsp (work, (void *)neg_rsp +4 , +sizeof (struct smb_negotiate_rsp ) -4 ))return -ENOMEM ; neg_rsp->hdr.Status.CifsError =STATUS_SUCCESS ;
Signature · 1 line
2.25.1