The patch below does not apply to the 4.16-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 8bd68c6e47abff34e412a0c68cecb4a36bf0198b Mon Sep 17 00:00:00 2001
From: Aurelien Aptel aaptel@suse.com Date: Fri, 16 Feb 2018 19:19:29 +0100 Subject: [PATCH] CIFS: implement v3.11 preauth integrity
SMB3.11 clients must implement pre-authentification integrity.
* new mechanism to certify requests/responses happening before Tree Connect. * supersedes VALIDATE_NEGOTIATE * fixes signing for SMB3.11
Signed-off-by: Aurelien Aptel aaptel@suse.com Signed-off-by: Steve French smfrench@gmail.com CC: Stable stable@vger.kernel.org Reviewed-by: Ronnie Sahlberg lsahlber@redhat.com
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 765fc2c9fd91..c294093f04d5 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -675,7 +675,8 @@ struct TCP_Server_Info { unsigned int max_read; unsigned int max_write; #ifdef CONFIG_CIFS_SMB311 - __u8 preauth_sha_hash[64]; /* save initital negprot hash */ + /* save initital negprot hash */ + __u8 preauth_sha_hash[SMB2_PREAUTH_HASH_SIZE]; #endif /* 3.1.1 */ struct delayed_work reconnect; /* reconnect workqueue job */ struct mutex reconnect_mutex; /* prevent simultaneous reconnects */ @@ -864,7 +865,7 @@ struct cifs_ses { __u8 smb3encryptionkey[SMB3_SIGN_KEY_SIZE]; __u8 smb3decryptionkey[SMB3_SIGN_KEY_SIZE]; #ifdef CONFIG_CIFS_SMB311 - __u8 preauth_sha_hash[64]; + __u8 preauth_sha_hash[SMB2_PREAUTH_HASH_SIZE]; #endif /* 3.1.1 */ };
diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c index 76d03abaa38c..da012c3ab700 100644 --- a/fs/cifs/smb2misc.c +++ b/fs/cifs/smb2misc.c @@ -706,3 +706,67 @@ smb2_handle_cancelled_mid(char *buffer, struct TCP_Server_Info *server)
return 0; } + +#ifdef CONFIG_CIFS_SMB311 +/** + * smb311_update_preauth_hash - update @ses hash with the packet data in @iov + * + * Assumes @iov does not contain the rfc1002 length and iov[0] has the + * SMB2 header. + */ +int +smb311_update_preauth_hash(struct cifs_ses *ses, struct kvec *iov, int nvec) +{ + int i, rc; + struct sdesc *d; + struct smb2_sync_hdr *hdr; + + if (ses->server->tcpStatus == CifsGood) { + /* skip non smb311 connections */ + if (ses->server->dialect != SMB311_PROT_ID) + return 0; + + /* skip last sess setup response */ + hdr = (struct smb2_sync_hdr *)iov[0].iov_base; + if (hdr->Flags & SMB2_FLAGS_SIGNED) + return 0; + } + + rc = smb311_crypto_shash_allocate(ses->server); + if (rc) + return rc; + + d = ses->server->secmech.sdescsha512; + rc = crypto_shash_init(&d->shash); + if (rc) { + cifs_dbg(VFS, "%s: could not init sha512 shash\n", __func__); + return rc; + } + + rc = crypto_shash_update(&d->shash, ses->preauth_sha_hash, + SMB2_PREAUTH_HASH_SIZE); + if (rc) { + cifs_dbg(VFS, "%s: could not update sha512 shash\n", __func__); + return rc; + } + + for (i = 0; i < nvec; i++) { + rc = crypto_shash_update(&d->shash, + iov[i].iov_base, iov[i].iov_len); + if (rc) { + cifs_dbg(VFS, "%s: could not update sha512 shash\n", + __func__); + return rc; + } + } + + rc = crypto_shash_final(&d->shash, ses->preauth_sha_hash); + if (rc) { + cifs_dbg(VFS, "%s: could not finalize sha512 shash\n", + __func__); + return rc; + } + + return 0; +} +#endif diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index ab4c20687cc0..4b6920de2541 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -453,6 +453,10 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses) return rc;
req->sync_hdr.SessionId = 0; +#ifdef CONFIG_CIFS_SMB311 + memset(server->preauth_sha_hash, 0, SMB2_PREAUTH_HASH_SIZE); + memset(ses->preauth_sha_hash, 0, SMB2_PREAUTH_HASH_SIZE); +#endif
if (strcmp(ses->server->vals->version_string, SMB3ANY_VERSION_STRING) == 0) { @@ -564,6 +568,15 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
/* BB: add check that dialect was valid given dialect(s) we asked for */
+#ifdef CONFIG_CIFS_SMB311 + /* + * Keep a copy of the hash after negprot. This hash will be + * the starting hash value for all sessions made from this + * server. + */ + memcpy(server->preauth_sha_hash, ses->preauth_sha_hash, + SMB2_PREAUTH_HASH_SIZE); +#endif /* SMB2 only has an extended negflavor */ server->negflavor = CIFS_NEGFLAVOR_EXTENDED; /* set it to the maximum buffer size value we can send with 1 credit */ @@ -621,6 +634,10 @@ int smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon *tcon) return 0; #endif
+ /* In SMB3.11 preauth integrity supersedes validate negotiate */ + if (tcon->ses->server->dialect == SMB311_PROT_ID) + return 0; + /* * validation ioctl must be signed, so no point sending this if we * can not sign it (ie are not known user). Even if signing is not @@ -1148,6 +1165,14 @@ SMB2_sess_setup(const unsigned int xid, struct cifs_ses *ses, sess_data->buf0_type = CIFS_NO_BUFFER; sess_data->nls_cp = (struct nls_table *) nls_cp;
+#ifdef CONFIG_CIFS_SMB311 + /* + * Initialize the session hash with the server one. + */ + memcpy(ses->preauth_sha_hash, ses->server->preauth_sha_hash, + SMB2_PREAUTH_HASH_SIZE); +#endif + while (sess_data->func) sess_data->func(sess_data);
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h index 2a2b34ccaf49..8b901c69a65a 100644 --- a/fs/cifs/smb2pdu.h +++ b/fs/cifs/smb2pdu.h @@ -264,6 +264,7 @@ struct smb2_negotiate_req { #define SMB311_SALT_SIZE 32 /* Hash Algorithm Types */ #define SMB2_PREAUTH_INTEGRITY_SHA512 cpu_to_le16(0x0001) +#define SMB2_PREAUTH_HASH_SIZE 64
struct smb2_preauth_neg_context { __le16 ContextType; /* 1 */ diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h index 3b8e9c2e55bc..cbcce3f7e86f 100644 --- a/fs/cifs/smb2proto.h +++ b/fs/cifs/smb2proto.h @@ -204,5 +204,7 @@ extern enum securityEnum smb2_select_sectype(struct TCP_Server_Info *, enum securityEnum); #ifdef CONFIG_CIFS_SMB311 extern int smb311_crypto_shash_allocate(struct TCP_Server_Info *server); +extern int smb311_update_preauth_hash(struct cifs_ses *ses, + struct kvec *iov, int nvec); #endif #endif /* _SMB2PROTO_H */ diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index 9779b3292d8e..665661464067 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -37,6 +37,7 @@ #include "cifsglob.h" #include "cifsproto.h" #include "cifs_debug.h" +#include "smb2proto.h" #include "smbdirect.h"
/* Max number of iovectors we can use off the stack when sending requests. */ @@ -751,6 +752,12 @@ cifs_send_recv(const unsigned int xid, struct cifs_ses *ses, if (rc < 0) goto out;
+#ifdef CONFIG_CIFS_SMB311 + if (ses->status == CifsNew) + smb311_update_preauth_hash(ses, rqst->rq_iov+1, + rqst->rq_nvec-1); +#endif + if (timeout == CIFS_ASYNC_OP) goto out;
@@ -789,6 +796,16 @@ cifs_send_recv(const unsigned int xid, struct cifs_ses *ses, else *resp_buf_type = CIFS_SMALL_BUFFER;
+#ifdef CONFIG_CIFS_SMB311 + if (ses->status == CifsNew) { + struct kvec iov = { + .iov_base = buf + 4, + .iov_len = get_rfc1002_length(buf) + }; + smb311_update_preauth_hash(ses, &iov, 1); + } +#endif + credits = ses->server->ops->get_credits(midQ);
rc = ses->server->ops->check_receive(midQ, ses->server,