From 52aaf5df75957ec714efdba7828cf212ac78c980 Mon Sep 17 00:00:00 2001 From: Sachin Prabhu Date: Wed, 18 Jan 2017 15:35:57 +0530 Subject: [PATCH] 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/cifsglob.h | 3 +++ fs/cifs/cifsproto.h | 2 ++ fs/cifs/connect.c | 3 ++- fs/cifs/sess.c | 4 ++-- fs/cifs/smb1ops.c | 1 + fs/cifs/smb2ops.c | 4 ++++ fs/cifs/smb2pdu.c | 37 +++++++++++++++++++++++++++++++++---- fs/cifs/smb2proto.h | 2 ++ 8 files changed, 49 insertions(+), 7 deletions(-) diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index af224cda86971..d42dd32886478 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -443,6 +443,9 @@ struct smb_version_operations { int (*is_transform_hdr)(void *buf); int (*receive_transform)(struct TCP_Server_Info *, struct mid_q_entry **); + enum securityEnum (*select_sectype)(struct TCP_Server_Info *, + enum securityEnum); + }; struct smb_version_values { diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h index 9ee46c1c3ebda..97e5d236d2655 100644 --- a/fs/cifs/cifsproto.h +++ b/fs/cifs/cifsproto.h @@ -533,4 +533,6 @@ int cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon, int __cifs_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server, char *signature, struct shash_desc *shash); +enum securityEnum cifs_select_sectype(struct TCP_Server_Info *, + enum securityEnum); #endif /* _CIFSPROTO_H */ diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 777ad9f4fc3c8..de4c56e8fb375 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -2073,7 +2073,8 @@ match_security(struct TCP_Server_Info *server, struct smb_vol *vol) * that was specified, or "Unspecified" if that sectype was not * compatible with the given NEGOTIATE request. */ - if (select_sectype(server, vol->sectype) == Unspecified) + if (server->ops->select_sectype(server, vol->sectype) + == Unspecified) return false; /* diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c index dcbcc927399a0..8b0502cd39afb 100644 --- a/fs/cifs/sess.c +++ b/fs/cifs/sess.c @@ -498,7 +498,7 @@ setup_ntlmv2_ret: } enum securityEnum -select_sectype(struct TCP_Server_Info *server, enum securityEnum requested) +cifs_select_sectype(struct TCP_Server_Info *server, enum securityEnum requested) { switch (server->negflavor) { case CIFS_NEGFLAVOR_EXTENDED: @@ -1391,7 +1391,7 @@ static int select_sec(struct cifs_ses *ses, struct sess_data *sess_data) { int type; - type = select_sectype(ses->server, ses->sectype); + type = cifs_select_sectype(ses->server, ses->sectype); cifs_dbg(FYI, "sess setup type %d\n", type); if (type == Unspecified) { cifs_dbg(VFS, diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c index 67a987e4d026e..cc93ba4da9b59 100644 --- a/fs/cifs/smb1ops.c +++ b/fs/cifs/smb1ops.c @@ -1087,6 +1087,7 @@ struct smb_version_operations smb1_operations = { .is_read_op = cifs_is_read_op, .wp_retry_size = cifs_wp_retry_size, .dir_needs_close = cifs_dir_needs_close, + .select_sectype = cifs_select_sectype, #ifdef CONFIG_CIFS_XATTR .query_all_EAs = CIFSSMBQAllEAs, .set_EA = CIFSSMBSetEA, diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index b360c381b00ec..0231108d9387a 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -2381,6 +2381,7 @@ struct smb_version_operations smb20_operations = { .wp_retry_size = smb2_wp_retry_size, .dir_needs_close = smb2_dir_needs_close, .get_dfs_refer = smb2_get_dfs_refer, + .select_sectype = smb2_select_sectype, }; struct smb_version_operations smb21_operations = { @@ -2463,6 +2464,7 @@ struct smb_version_operations smb21_operations = { .dir_needs_close = smb2_dir_needs_close, .enum_snapshots = smb3_enum_snapshots, .get_dfs_refer = smb2_get_dfs_refer, + .select_sectype = smb2_select_sectype, }; struct smb_version_operations smb30_operations = { @@ -2555,6 +2557,7 @@ struct smb_version_operations smb30_operations = { .is_transform_hdr = smb3_is_transform_hdr, .receive_transform = smb3_receive_transform, .get_dfs_refer = smb2_get_dfs_refer, + .select_sectype = smb2_select_sectype, }; #ifdef CONFIG_CIFS_SMB311 @@ -2648,6 +2651,7 @@ struct smb_version_operations smb311_operations = { .is_transform_hdr = smb3_is_transform_hdr, .receive_transform = smb3_receive_transform, .get_dfs_refer = smb2_get_dfs_refer, + .select_sectype = smb2_select_sectype, }; #endif /* CIFS_SMB311 */ diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 2069431b32e36..7446496850a3b 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; } diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h index 11d9f3013db85..69e35873b1de7 100644 --- a/fs/cifs/smb2proto.h +++ b/fs/cifs/smb2proto.h @@ -181,4 +181,6 @@ extern int SMB2_lease_break(const unsigned int xid, struct cifs_tcon *tcon, __u8 *lease_key, const __le32 lease_state); extern int smb3_validate_negotiate(const unsigned int, struct cifs_tcon *); +extern enum securityEnum smb2_select_sectype(struct TCP_Server_Info *, + enum securityEnum); #endif /* _SMB2PROTO_H */ -- 2.39.5