Reviewed-by: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>
On Thu, Jan 3, 2019 at 6:45 PM Steve French via samba-technical
<samba-technical@xxxxxxxxxxxxxxx> wrote:
>
> SMB3.1.1 dialect has additional security (among other) features
> and should be requested when mounting to modern servers so it
> can be used if the server supports it.
>
> Add SMB3.1.1 to the default list of dialects requested.
>
> Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
> ---
> fs/cifs/smb2pdu.c | 38 ++++++++++++++++++++++++++------------
> 1 file changed, 26 insertions(+), 12 deletions(-)
>
> diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
> index e283590955cd..9bc1dec84b35 100644
> --- a/fs/cifs/smb2pdu.c
> +++ b/fs/cifs/smb2pdu.c
> @@ -451,10 +451,6 @@ smb2_plain_req_init(__le16 smb2_command, struct
> cifs_tcon *tcon,
> }
>
>
> -/* offset is sizeof smb2_negotiate_req but rounded up to 8 bytes */
> -#define OFFSET_OF_NEG_CONTEXT 0x68 /* sizeof(struct smb2_negotiate_req) */
> -
> -
> #define SMB2_PREAUTH_INTEGRITY_CAPABILITIES cpu_to_le16(1)
> #define SMB2_ENCRYPTION_CAPABILITIES cpu_to_le16(2)
> #define SMB2_POSIX_EXTENSIONS_AVAILABLE cpu_to_le16(0x100)
> @@ -491,10 +487,24 @@ static void
> assemble_neg_contexts(struct smb2_negotiate_req *req,
> unsigned int *total_len)
> {
> - char *pneg_ctxt = (char *)req + OFFSET_OF_NEG_CONTEXT;
> + char *pneg_ctxt = (char *)req;
> unsigned int ctxt_len;
>
> - *total_len += 2; /* Add 2 due to round to 8 byte boundary for 1st ctxt */
> + if (*total_len > 200) {
> + /* In case length corrupted don't want to overrun smb buffer */
> + cifs_dbg(VFS, "Bad frame length assembling neg contexts\n");
> + return;
> + }
> +
> + /*
> + * round up total_len of fixed part of SMB3 negotiate request to 8
> + * byte boundary before adding negotiate contexts
> + */
> + *total_len = roundup(*total_len, 8);
> +
> + pneg_ctxt = (*total_len) + (char *)req;
> + req->NegotiateContextOffset = cpu_to_le32(*total_len);
> +
> build_preauth_ctxt((struct smb2_preauth_neg_context *)pneg_ctxt);
> ctxt_len = DIV_ROUND_UP(sizeof(struct smb2_preauth_neg_context), 8) * 8;
> *total_len += ctxt_len;
> @@ -508,7 +518,6 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
> build_posix_ctxt((struct smb2_posix_neg_context *)pneg_ctxt);
> *total_len += sizeof(struct smb2_posix_neg_context);
>
> - req->NegotiateContextOffset = cpu_to_le32(OFFSET_OF_NEG_CONTEXT);
> req->NegotiateContextCount = cpu_to_le16(3);
> }
>
> @@ -724,8 +733,9 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
> req->Dialects[0] = cpu_to_le16(SMB21_PROT_ID);
> req->Dialects[1] = cpu_to_le16(SMB30_PROT_ID);
> req->Dialects[2] = cpu_to_le16(SMB302_PROT_ID);
> - req->DialectCount = cpu_to_le16(3);
> - total_len += 6;
> + req->Dialects[3] = cpu_to_le16(SMB311_PROT_ID);
> + req->DialectCount = cpu_to_le16(4);
> + total_len += 8;
> } else {
> /* otherwise send specific dialect */
> req->Dialects[0] = cpu_to_le16(ses->server->vals->protocol_id);
> @@ -749,7 +759,9 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
> else {
> memcpy(req->ClientGUID, server->client_guid,
> SMB2_CLIENT_GUID_SIZE);
> - if (ses->server->vals->protocol_id == SMB311_PROT_ID)
> + if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
> + (strcmp(ses->server->vals->version_string,
> + SMBDEFAULT_VERSION_STRING) == 0))
> assemble_neg_contexts(req, &total_len);
> }
> iov[0].iov_base = (char *)req;
> @@ -794,7 +806,8 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
> } else if (rsp->DialectRevision == cpu_to_le16(SMB21_PROT_ID)) {
> /* ops set to 3.0 by default for default so update */
> ses->server->ops = &smb21_operations;
> - }
> + } else if (rsp->DialectRevision == cpu_to_le16(SMB311_PROT_ID))
> + ses->server->ops = &smb311_operations;
> } else if (le16_to_cpu(rsp->DialectRevision) !=
> ses->server->vals->protocol_id) {
> /* if requested single dialect ensure returned dialect matched */
> @@ -947,7 +960,8 @@ int smb3_validate_negotiate(const unsigned int
> xid, struct cifs_tcon *tcon)
> pneg_inbuf->Dialects[0] = cpu_to_le16(SMB21_PROT_ID);
> pneg_inbuf->Dialects[1] = cpu_to_le16(SMB30_PROT_ID);
> pneg_inbuf->Dialects[2] = cpu_to_le16(SMB302_PROT_ID);
> - pneg_inbuf->DialectCount = cpu_to_le16(3);
> + pneg_inbuf->Dialects[3] = cpu_to_le16(SMB311_PROT_ID);
> + pneg_inbuf->DialectCount = cpu_to_le16(4);
> /* structure is big enough for 3 dialects */
> inbuflen = sizeof(*pneg_inbuf);
> } else {
> --
>
>
> --
> Thanks,
>
> Steve
