Re: [PATCH] ksmbd: Fix to handle removal of rfc1002 header from smb_hdr

ChenXiaoSong
2025-12-18T15:09:54Z

`ksmbd_conn_handler_loop()` calls `get_rfc1002_len()`. Does this need to
be updated as well?

Thanks,
ChenXiaoSong.

On 12/18/25 10:48 PM, David Howells wrote:
> Hi Namjae,
>
> Does this (untested) patch fix the problem for you?
>
> David
> ---
> The commit that removed the RFC1002 header from struct smb_hdr didn't also
> fix the places in ksmbd that use it in order to provide graceful rejection
> of SMB1 protocol requests.
>
> Fixes: 83bfbd0bb902 ("cifs: Remove the RFC1002 header from smb_hdr")
> Reported-by: Namjae Jeon <linkinjeon@kernel.org>
> Link: https://lore.kernel.org/r/CAKYAXd9Ju4MFkkH5Jxfi1mO0AWEr=R35M3vQ_Xa7Yw34JoNZ0A@mail.gmail.com/
> Signed-off-by: David Howells <dhowells@redhat.com>
> cc: Steve French <sfrench@samba.org>
> cc: Sergey Senozhatsky <senozhatsky@chromium.org>
> cc: Tom Talpey <tom@talpey.com>
> cc: Paulo Alcantara <pc@manguebit.org>
> cc: Shyam Prasad N <sprasad@microsoft.com>
> cc: linux-cifs@vger.kernel.org
> cc: netfs@lists.linux.dev
> cc: linux-fsdevel@vger.kernel.org
> ---
> fs/smb/server/server.c | 2 +-
> fs/smb/server/smb_common.c | 10 +++++-----
> 2 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/fs/smb/server/server.c b/fs/smb/server/server.c
> index 3cea16050e4f..bedc8390b6db 100644
> --- a/fs/smb/server/server.c
> +++ b/fs/smb/server/server.c
> @@ -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 = work->response_buf;
> + rsp_hdr = smb2_get_msg(work->response_buf);
> rsp_hdr->Status.CifsError = STATUS_CONNECTION_DISCONNECTED;
> return 1;
> }
> diff --git a/fs/smb/server/smb_common.c b/fs/smb/server/smb_common.c
> index b23203a1c286..d6084580b59d 100644
> --- a/fs/smb/server/smb_common.c
> +++ b/fs/smb/server/smb_common.c
> @@ -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 = work->request_buf;
> + hdr = smb2_get_msg(work->request_buf);
> if (*(__le32 *)hdr->Protocol == SMB1_PROTO_NUMBER &&
> hdr->Command == SMB_COM_NEGOTIATE) {
> work->conn->outstanding_credits++;
> @@ -278,7 +278,6 @@ 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;
>
> @@ -320,8 +319,8 @@ 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 *)work->response_buf;
> - struct smb_hdr *rcv_hdr = (struct smb_hdr *)work->request_buf;
> + struct smb_hdr *rsp_hdr = (struct smb_hdr *)smb2_get_msg(work->response_buf);
> + struct smb_hdr *rcv_hdr = (struct smb_hdr *)smb2_get_msg(work->request_buf);
>
> rsp_hdr->Command = SMB_COM_NEGOTIATE;
> *(__le32 *)rsp_hdr->Protocol = SMB1_PROTO_NUMBER;
> @@ -412,9 +411,10 @@ 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 *)smb2_get_msg(conn->request_buf);
> __le32 proto;
>
> - proto = *(__le32 *)((struct smb_hdr *)conn->request_buf)->Protocol;
> + proto = *(__le32 *)rcv_hdr->Protocol;
> if (conn->need_neg == false) {
> if (proto == SMB1_PROTO_NUMBER)
> return -EINVAL;
>
>