13 cifs/smb3 fixes. Most are to address minor issues pointed out by Coverity. Also includes a packet signing enhancement and mount improvement

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Merge tag '5.14-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "13 cifs/smb3 fixes. Most are to address minor issues pointed out by
  Coverity.

  Also includes a packet signing enhancement and mount improvement"

* tag '5.14-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: update internal version number
  cifs: prevent NULL deref in cifs_compose_mount_options()
  SMB3.1.1: Add support for negotiating signing algorithm
  cifs: use helpers when parsing uid/gid mount options and validate them
  CIFS: Clarify SMB1 code for POSIX Lock
  CIFS: Clarify SMB1 code for rename open file
  CIFS: Clarify SMB1 code for delete
  CIFS: Clarify SMB1 code for SetFileSize
  smb3: fix typo in header file
  CIFS: Clarify SMB1 code for UnixSetPathInfo
  CIFS: Clarify SMB1 code for UnixCreateSymLink
  cifs: clarify SMB1 code for UnixCreateHardLink
  cifs: make locking consistent around the server session status

fs/cifs/cifs_dfs_ref.c

@@ -151,6 +151,9 @@ char *cifs_compose_mount_options(const char *sb_mountdata,
 		return ERR_PTR(-EINVAL);
 
 	if (ref) {
+		if (WARN_ON_ONCE(!ref->node_name || ref->path_consumed < 0))
+			return ERR_PTR(-EINVAL);
+
 		if (strlen(fullpath) - ref->path_consumed) {
 			prepath = fullpath + ref->path_consumed;
 			/* skip initial delimiter */

fs/cifs/cifsfs.c

@@ -65,6 +65,7 @@ bool lookupCacheEnabled = true;
 bool disable_legacy_dialects; /* false by default */
 bool enable_gcm_256 = true;
 bool require_gcm_256; /* false by default */
+bool enable_negotiate_signing; /* false by default */
 unsigned int global_secflags = CIFSSEC_DEF;
 /* unsigned int ntlmv2_support = 0; */
 unsigned int sign_CIFS_PDUs = 1;
@@ -104,6 +105,9 @@ MODULE_PARM_DESC(enable_gcm_256, "Enable requesting strongest (256 bit) GCM encr
 module_param(require_gcm_256, bool, 0644);
 MODULE_PARM_DESC(require_gcm_256, "Require strongest (256 bit) GCM encryption. Default: n/N/0");
 
+module_param(enable_negotiate_signing, bool, 0644);
+MODULE_PARM_DESC(enable_negotiate_signing, "Enable negotiating packet signing algorithm with server. Default: n/N/0");
+
 module_param(disable_legacy_dialects, bool, 0644);
 MODULE_PARM_DESC(disable_legacy_dialects, "To improve security it may be "
 				  "helpful to restrict the ability to "

fs/cifs/cifsfs.h

@@ -153,5 +153,5 @@ extern struct dentry *cifs_smb3_do_mount(struct file_system_type *fs_type,
 extern const struct export_operations cifs_export_ops;
 #endif /* CONFIG_CIFS_NFSD_EXPORT */
 
-#define CIFS_VERSION   "2.32"
+#define CIFS_VERSION   "2.33"
 #endif				/* _CIFSFS_H */

fs/cifs/cifsglob.h

@@ -577,6 +577,7 @@ struct TCP_Server_Info {
 	char server_RFC1001_name[RFC1001_NAME_LEN_WITH_NULL];
 	struct smb_version_operations	*ops;
 	struct smb_version_values	*vals;
+	/* updates to tcpStatus protected by GlobalMid_Lock */
 	enum statusEnum tcpStatus; /* what we think the status is */
 	char *hostname; /* hostname portion of UNC string */
 	struct socket *ssocket;
@@ -666,9 +667,11 @@ struct TCP_Server_Info {
 	unsigned int	max_write;
 	unsigned int	min_offload;
 	__le16	compress_algorithm;
+	__u16	signing_algorithm;
 	__le16	cipher_type;
 	 /* save initital negprot hash */
 	__u8	preauth_sha_hash[SMB2_PREAUTH_HASH_SIZE];
+	bool	signing_negotiated; /* true if valid signing context rcvd from server */
 	bool	posix_ext_supported;
 	struct delayed_work reconnect; /* reconnect workqueue job */
 	struct mutex reconnect_mutex; /* prevent simultaneous reconnects */
@@ -1785,7 +1788,7 @@ require use of the stronger protocol */
  *	list operations on pending_mid_q and oplockQ
  *      updates to XID counters, multiplex id  and SMB sequence numbers
  *      list operations on global DnotifyReqList
- *      updates to ses->status
+ *      updates to ses->status and TCP_Server_Info->tcpStatus
  *      updates to server->CurrentMid
  *  tcp_ses_lock protects:
  *	list operations on tcp and SMB session lists
@@ -1868,6 +1871,7 @@ extern unsigned int global_secflags;	/* if on, session setup sent
 extern unsigned int sign_CIFS_PDUs;  /* enable smb packet signing */
 extern bool enable_gcm_256; /* allow optional negotiate of strongest signing (aes-gcm-256) */
 extern bool require_gcm_256; /* require use of strongest signing (aes-gcm-256) */
+extern bool enable_negotiate_signing; /* request use of faster (GMAC) signing if available */
 extern bool linuxExtEnabled;/*enable Linux/Unix CIFS extensions*/
 extern unsigned int CIFSMaxBufSize;  /* max size not including hdr */
 extern unsigned int cifs_min_rcv;    /* min size of big ntwrk buf pool */

fs/cifs/cifspdu.h

@@ -1785,6 +1785,7 @@ struct smb_com_transaction2_sfi_req {
 	__u16 Fid;
 	__le16 InformationLevel;
 	__u16 Reserved4;
+	__u8  payload[];
 } __attribute__((packed));
 
 struct smb_com_transaction2_sfi_rsp {

fs/cifs/cifssmb.c

@@ -2537,8 +2537,9 @@ CIFSSMBPosixLock(const unsigned int xid, struct cifs_tcon *tcon,
 	pSMB->TotalDataCount = pSMB->DataCount;
 	pSMB->TotalParameterCount = pSMB->ParameterCount;
 	pSMB->ParameterOffset = cpu_to_le16(param_offset);
+	/* SMB offsets are from the beginning of SMB which is 4 bytes in, after RFC1001 field */
 	parm_data = (struct cifs_posix_lock *)
-			(((char *) &pSMB->hdr.Protocol) + offset);
+			(((char *)pSMB) + offset + 4);
 
 	parm_data->lock_type = cpu_to_le16(lock_type);
 	if (waitFlag) {
@@ -2767,7 +2768,8 @@ int CIFSSMBRenameOpenFile(const unsigned int xid, struct cifs_tcon *pTcon,
 	param_offset = offsetof(struct smb_com_transaction2_sfi_req, Fid) - 4;
 	offset = param_offset + params;
 
-	data_offset = (char *) (&pSMB->hdr.Protocol) + offset;
+	/* SMB offsets are from the beginning of SMB which is 4 bytes in, after RFC1001 field */
+	data_offset = (char *)(pSMB) + offset + 4;
 	rename_info = (struct set_file_rename *) data_offset;
 	pSMB->MaxParameterCount = cpu_to_le16(2);
 	pSMB->MaxDataCount = cpu_to_le16(1000); /* BB find max SMB from sess */
@@ -2925,7 +2927,8 @@ createSymLinkRetry:
 				InformationLevel) - 4;
 	offset = param_offset + params;
 
-	data_offset = (char *) (&pSMB->hdr.Protocol) + offset;
+	/* SMB offsets are from the beginning of SMB which is 4 bytes in, after RFC1001 field */
+	data_offset = (char *)pSMB + offset + 4;
 	if (pSMB->hdr.Flags2 & SMBFLG2_UNICODE) {
 		name_len_target =
 		    cifsConvertToUTF16((__le16 *) data_offset, toName,
@@ -3009,7 +3012,8 @@ createHardLinkRetry:
 				InformationLevel) - 4;
 	offset = param_offset + params;
 
-	data_offset = (char *) (&pSMB->hdr.Protocol) + offset;
+	/* SMB offsets are from the beginning of SMB which is 4 bytes in, after RFC1001 field */
+	data_offset = (char *)pSMB + offset + 4;
 	if (pSMB->hdr.Flags2 & SMBFLG2_UNICODE) {
 		name_len_target =
 		    cifsConvertToUTF16((__le16 *) data_offset, fromName,
@@ -5626,9 +5630,9 @@ CIFSSMBSetFileSize(const unsigned int xid, struct cifs_tcon *tcon,
 	pSMB->TotalDataCount = pSMB->DataCount;
 	pSMB->TotalParameterCount = pSMB->ParameterCount;
 	pSMB->ParameterOffset = cpu_to_le16(param_offset);
+	/* SMB offsets are from the beginning of SMB which is 4 bytes in, after RFC1001 field */
 	parm_data =
-		(struct file_end_of_file_info *) (((char *) &pSMB->hdr.Protocol)
-				+ offset);
+		(struct file_end_of_file_info *)(((char *)pSMB) + offset + 4);
 	pSMB->DataOffset = cpu_to_le16(offset);
 	parm_data->FileSize = cpu_to_le64(size);
 	pSMB->Fid = cfile->fid.netfid;
@@ -5761,7 +5765,8 @@ CIFSSMBSetFileDisposition(const unsigned int xid, struct cifs_tcon *tcon,
 	param_offset = offsetof(struct smb_com_transaction2_sfi_req, Fid) - 4;
 	offset = param_offset + params;
 
-	data_offset = (char *) (&pSMB->hdr.Protocol) + offset;
+	/* SMB offsets are from the beginning of SMB which is 4 bytes in, after RFC1001 field */
+	data_offset = (char *)(pSMB) + offset + 4;
 
 	count = 1;
 	pSMB->MaxParameterCount = cpu_to_le16(2);
@@ -6062,9 +6067,8 @@ setPermsRetry:
 	param_offset = offsetof(struct smb_com_transaction2_spi_req,
 				InformationLevel) - 4;
 	offset = param_offset + params;
-	data_offset =
-	    (FILE_UNIX_BASIC_INFO *) ((char *) &pSMB->hdr.Protocol +
-				      offset);
+	/* SMB offsets are from the beginning of SMB which is 4 bytes in, after RFC1001 field */
+	data_offset = (FILE_UNIX_BASIC_INFO *)((char *) pSMB + offset + 4);
 	memset(data_offset, 0, count);
 	pSMB->DataOffset = cpu_to_le16(offset);
 	pSMB->ParameterOffset = cpu_to_le16(param_offset);

fs/cifs/connect.c

@@ -1403,6 +1403,11 @@ smbd_connected:
 		goto out_err_crypto_release;
 	}
 	tcp_ses->min_offload = ctx->min_offload;
+	/*
+	 * at this point we are the only ones with the pointer
+	 * to the struct since the kernel thread not created yet
+	 * no need to spinlock this update of tcpStatus
+	 */
 	tcp_ses->tcpStatus = CifsNeedNegotiate;
 
 	if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))

fs/cifs/fs_context.c

@@ -322,7 +322,6 @@ smb3_fs_context_dup(struct smb3_fs_context *new_ctx, struct smb3_fs_context *ctx
 	new_ctx->UNC = NULL;
 	new_ctx->source = NULL;
 	new_ctx->iocharset = NULL;
-
 	/*
 	 * Make sure to stay in sync with smb3_cleanup_fs_context_contents()
 	 */
@@ -792,6 +791,8 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
 	int i, opt;
 	bool is_smb3 = !strcmp(fc->fs_type->name, "smb3");
 	bool skip_parsing = false;
+	kuid_t uid;
+	kgid_t gid;
 
 	cifs_dbg(FYI, "CIFS: parsing cifs mount option '%s'\n", param->key);
 
@@ -904,18 +905,31 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
 		}
 		break;
 	case Opt_uid:
-		ctx->linux_uid.val = result.uint_32;
+		uid = make_kuid(current_user_ns(), result.uint_32);
+		if (!uid_valid(uid))
+			goto cifs_parse_mount_err;
+		ctx->linux_uid = uid;
 		ctx->uid_specified = true;
 		break;
 	case Opt_cruid:
-		ctx->cred_uid.val = result.uint_32;
+		uid = make_kuid(current_user_ns(), result.uint_32);
+		if (!uid_valid(uid))
+			goto cifs_parse_mount_err;
+		ctx->cred_uid = uid;
+		ctx->cruid_specified = true;
 		break;
 	case Opt_backupgid:
-		ctx->backupgid.val = result.uint_32;
+		gid = make_kgid(current_user_ns(), result.uint_32);
+		if (!gid_valid(gid))
+			goto cifs_parse_mount_err;
+		ctx->backupgid = gid;
 		ctx->backupgid_specified = true;
 		break;
 	case Opt_gid:
-		ctx->linux_gid.val = result.uint_32;
+		gid = make_kgid(current_user_ns(), result.uint_32);
+		if (!gid_valid(gid))
+			goto cifs_parse_mount_err;
+		ctx->linux_gid = gid;
 		ctx->gid_specified = true;
 		break;
 	case Opt_port:

fs/cifs/fs_context.h

@@ -155,6 +155,7 @@ enum cifs_param {
 
 struct smb3_fs_context {
 	bool uid_specified;
+	bool cruid_specified;
 	bool gid_specified;
 	bool sloppy;
 	bool got_ip;

fs/cifs/smb2pdu.c

@@ -433,6 +433,29 @@ build_compression_ctxt(struct smb2_compression_capabilities_context *pneg_ctxt)
 	pneg_ctxt->CompressionAlgorithms[2] = SMB3_COMPRESS_LZNT1;
 }
 
+static unsigned int
+build_signing_ctxt(struct smb2_signing_capabilities *pneg_ctxt)
+{
+	unsigned int ctxt_len = sizeof(struct smb2_signing_capabilities);
+	unsigned short num_algs = 1; /* number of signing algorithms sent */
+
+	pneg_ctxt->ContextType = SMB2_SIGNING_CAPABILITIES;
+	/*
+	 * Context Data length must be rounded to multiple of 8 for some servers
+	 */
+	pneg_ctxt->DataLength = cpu_to_le16(DIV_ROUND_UP(
+				sizeof(struct smb2_signing_capabilities) -
+				sizeof(struct smb2_neg_context) +
+				(num_algs * 2 /* sizeof u16 */), 8) * 8);
+	pneg_ctxt->SigningAlgorithmCount = cpu_to_le16(num_algs);
+	pneg_ctxt->SigningAlgorithms[0] = cpu_to_le16(SIGNING_ALG_AES_CMAC);
+
+	ctxt_len += 2 /* sizeof le16 */ * num_algs;
+	ctxt_len = DIV_ROUND_UP(ctxt_len, 8) * 8;
+	return ctxt_len;
+	/* TBD add SIGNING_ALG_AES_GMAC and/or SIGNING_ALG_HMAC_SHA256 */
+}
+
 static void
 build_encrypt_ctxt(struct smb2_encryption_neg_context *pneg_ctxt)
 {
@@ -498,7 +521,7 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
 		      struct TCP_Server_Info *server, unsigned int *total_len)
 {
 	char *pneg_ctxt;
-	unsigned int ctxt_len;
+	unsigned int ctxt_len, neg_context_count;
 
 	if (*total_len > 200) {
 		/* In case length corrupted don't want to overrun smb buffer */
@@ -525,6 +548,17 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
 	*total_len += ctxt_len;
 	pneg_ctxt += ctxt_len;
 
+	ctxt_len = build_netname_ctxt((struct smb2_netname_neg_context *)pneg_ctxt,
+					server->hostname);
+	*total_len += ctxt_len;
+	pneg_ctxt += ctxt_len;
+
+	build_posix_ctxt((struct smb2_posix_neg_context *)pneg_ctxt);
+	*total_len += sizeof(struct smb2_posix_neg_context);
+	pneg_ctxt += sizeof(struct smb2_posix_neg_context);
+
+	neg_context_count = 4;
+
 	if (server->compress_algorithm) {
 		build_compression_ctxt((struct smb2_compression_capabilities_context *)
 				pneg_ctxt);
@@ -533,17 +567,20 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
 				8) * 8;
 		*total_len += ctxt_len;
 		pneg_ctxt += ctxt_len;
-		req->NegotiateContextCount = cpu_to_le16(5);
-	} else
-		req->NegotiateContextCount = cpu_to_le16(4);
+		neg_context_count++;
+	}
 
-	ctxt_len = build_netname_ctxt((struct smb2_netname_neg_context *)pneg_ctxt,
-					server->hostname);
-	*total_len += ctxt_len;
-	pneg_ctxt += ctxt_len;
+	if (enable_negotiate_signing) {
+		ctxt_len = build_signing_ctxt((struct smb2_signing_capabilities *)
+				pneg_ctxt);
+		*total_len += ctxt_len;
+		pneg_ctxt += ctxt_len;
+		neg_context_count++;
+	}
+
+	/* check for and add transport_capabilities and signing capabilities */
+	req->NegotiateContextCount = cpu_to_le16(neg_context_count);
 
-	build_posix_ctxt((struct smb2_posix_neg_context *)pneg_ctxt);
-	*total_len += sizeof(struct smb2_posix_neg_context);
 }
 
 static void decode_preauth_context(struct smb2_preauth_neg_context *ctxt)
@@ -632,6 +669,31 @@ static int decode_encrypt_ctx(struct TCP_Server_Info *server,
 	return 0;
 }
 
+static void decode_signing_ctx(struct TCP_Server_Info *server,
+			       struct smb2_signing_capabilities *pctxt)
+{
+	unsigned int len = le16_to_cpu(pctxt->DataLength);
+
+	if ((len < 4) || (len > 16)) {
+		pr_warn_once("server sent bad signing negcontext\n");
+		return;
+	}
+	if (le16_to_cpu(pctxt->SigningAlgorithmCount) != 1) {
+		pr_warn_once("Invalid signing algorithm count\n");
+		return;
+	}
+	if (le16_to_cpu(pctxt->SigningAlgorithms[0]) > 2) {
+		pr_warn_once("unknown signing algorithm\n");
+		return;
+	}
+
+	server->signing_negotiated = true;
+	server->signing_algorithm = le16_to_cpu(pctxt->SigningAlgorithms[0]);
+	cifs_dbg(FYI, "signing algorithm %d chosen\n",
+		     server->signing_algorithm);
+}
+
+
 static int smb311_decode_neg_context(struct smb2_negotiate_rsp *rsp,
 				     struct TCP_Server_Info *server,
 				     unsigned int len_of_smb)
@@ -675,6 +737,9 @@ static int smb311_decode_neg_context(struct smb2_negotiate_rsp *rsp,
 				(struct smb2_compression_capabilities_context *)pctx);
 		else if (pctx->ContextType == SMB2_POSIX_EXTENSIONS_AVAILABLE)
 			server->posix_ext_supported = true;
+		else if (pctx->ContextType == SMB2_SIGNING_CAPABILITIES)
+			decode_signing_ctx(server,
+				(struct smb2_signing_capabilities *)pctx);
 		else
 			cifs_server_dbg(VFS, "unknown negcontext of type %d ignored\n",
 				le16_to_cpu(pctx->ContextType));

fs/cifs/smb2pdu.h

@@ -13,7 +13,7 @@
 #define _SMB2PDU_H
 
 #include <net/sock.h>
-#include <cifsacl.h>
+#include "cifsacl.h"
 
 /*
  * Note that, due to trying to use names similar to the protocol specifications,
@@ -329,7 +329,7 @@ struct smb2_neg_context {
 	__le16	ContextType;
 	__le16	DataLength;
 	__le32	Reserved;
-	/* Followed by array of data */
+	/* Followed by array of data. NOTE: some servers require padding to 8 byte boundary */
 } __packed;
 
 #define SMB311_LINUX_CLIENT_SALT_SIZE			32
@@ -394,6 +394,7 @@ struct smb2_compression_capabilities_context {
 	__u16	Padding;
 	__u32	Flags;
 	__le16	CompressionAlgorithms[3];
+	/* Check if pad needed */
 } __packed;
 
 /*
@@ -420,6 +421,7 @@ struct smb2_transport_capabilities_context {
 	__le16  DataLength;
 	__u32	Reserved;
 	__le32	Flags;
+	__u32	Pad;
 } __packed;
 
 /*
@@ -458,6 +460,7 @@ struct smb2_signing_capabilities {
 	__u32	Reserved;
 	__le16	SigningAlgorithmCount;
 	__le16	SigningAlgorithms[];
+	/*  Followed by padding to 8 byte boundary (required by some servers) */
 } __packed;
 
 #define POSIX_CTXT_DATA_LEN	16

fs/cifs/transport.c

@@ -431,7 +431,9 @@ unmask:
 		 * be taken as the remainder of this one. We need to kill the
 		 * socket so the server throws away the partial SMB
 		 */
+		spin_lock(&GlobalMid_Lock);
 		server->tcpStatus = CifsNeedReconnect;
+		spin_unlock(&GlobalMid_Lock);
 		trace_smb3_partial_send_reconnect(server->CurrentMid,
 						  server->conn_id, server->hostname);
 	}