From ef65aaede23f75977af56a8c330bb9be8c6e125c Mon Sep 17 00:00:00 2001 From: Sachin Prabhu Date: Wed, 18 Jan 2017 15:35:57 +0530 Subject: smb2: Enforce sec= mount option If the security type specified using a mount option is not supported, the SMB2 session setup code changes the security type to RawNTLMSSP. We should instead fail the mount and return an error. The patch changes the code for SMB2 to make it similar to the code used for SMB1. Like in SMB1, we now use the global security flags to select the security method to be used when no security method is specified and to return an error when the requested auth method is not available. For SMB2, we also use ntlmv2 as a synonym for nltmssp. Signed-off-by: Sachin Prabhu Acked-by: Pavel Shilovsky Acked-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/smb2pdu.c | 37 +++++++++++++++++++++++++++++++++---- 1 file changed, 33 insertions(+), 4 deletions(-) (limited to 'fs/cifs/smb2pdu.c') diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 2069431b32e3..7446496850a3 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -657,6 +657,28 @@ vneg_out: return -EIO; } +enum securityEnum +smb2_select_sectype(struct TCP_Server_Info *server, enum securityEnum requested) +{ + switch (requested) { + case Kerberos: + case RawNTLMSSP: + return requested; + case NTLMv2: + return RawNTLMSSP; + case Unspecified: + if (server->sec_ntlmssp && + (global_secflags & CIFSSEC_MAY_NTLMSSP)) + return RawNTLMSSP; + if ((server->sec_kerberos || server->sec_mskerberos) && + (global_secflags & CIFSSEC_MAY_KRB5)) + return Kerberos; + /* Fallthrough */ + default: + return Unspecified; + } +} + struct SMB2_sess_data { unsigned int xid; struct cifs_ses *ses; @@ -1009,10 +1031,17 @@ out: static int SMB2_select_sec(struct cifs_ses *ses, struct SMB2_sess_data *sess_data) { - if (ses->sectype != Kerberos && ses->sectype != RawNTLMSSP) - ses->sectype = RawNTLMSSP; + int type; + + type = smb2_select_sectype(ses->server, ses->sectype); + cifs_dbg(FYI, "sess setup type %d\n", type); + if (type == Unspecified) { + cifs_dbg(VFS, + "Unable to select appropriate authentication method!"); + return -EINVAL; + } - switch (ses->sectype) { + switch (type) { case Kerberos: sess_data->func = SMB2_auth_kerberos; break; @@ -1020,7 +1049,7 @@ SMB2_select_sec(struct cifs_ses *ses, struct SMB2_sess_data *sess_data) sess_data->func = SMB2_sess_auth_rawntlmssp_negotiate; break; default: - cifs_dbg(VFS, "secType %d not supported!\n", ses->sectype); + cifs_dbg(VFS, "secType %d not supported!\n", type); return -EOPNOTSUPP; } -- cgit v1.2.1