Merge tag '4.18-fixes-smb3' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:

 - one smb3 (ACL related) fix for stable

 - one SMB3 security enhancement (when mounting -t smb3 forbid less
   secure dialects)

 - some RDMA and compounding fixes

* tag '4.18-fixes-smb3' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: fix a buffer leak in smb2_query_symlink
  smb3: do not allow insecure cifs mounts when using smb3
  CIFS: Fix NULL ptr deref
  CIFS: fix encryption in SMB3.1.1
  CIFS: Pass page offset for encrypting
  CIFS: Pass page offset for calculating signature
  CIFS: SMBD: Support page offset in memory registration
  CIFS: SMBD: Support page offset in RDMA recv
  CIFS: SMBD: Support page offset in RDMA send
  CIFS: When sending data on socket, pass the correct page offset
  CIFS: Introduce helper function to get page offset and length in smb_rqst
  CIFS: Calculate the correct request length based on page offset and tail size
  cifs: For SMB2 security informaion query, check for minimum sized security descriptor instead of sizeof FileAllInformation class
  CIFS: Fix signing for SMB2/3

Author: torvalds

fs/cifs/cifsacl.h

@@ -98,4 +98,18 @@ struct cifs_ace {
 	struct cifs_sid sid; /* ie UUID of user or group who gets these perms */
 } __attribute__((packed));
 
+/*
+ * Minimum security identifier can be one for system defined Users
+ * and Groups such as NULL SID and World or Built-in accounts such
+ * as Administrator and Guest and consists of
+ * Revision + Num (Sub)Auths + Authority + Domain (one Subauthority)
+ */
+#define MIN_SID_LEN  (1 + 1 + 6 + 4) /* in bytes */
+
+/*
+ * Minimum security descriptor can be one without any SACL and DACL and can
+ * consist of revision, type, and two sids of minimum size for owner and group
+ */
+#define MIN_SEC_DESC_LEN  (sizeof(struct cifs_ntsd) + (2 * MIN_SID_LEN))
+
 #endif /* _CIFSACL_H */

fs/cifs/cifsencrypt.c

@@ -37,6 +37,7 @@
 #include <crypto/aead.h>
 
 int __cifs_calc_signature(struct smb_rqst *rqst,
+			int start,
 			struct TCP_Server_Info *server, char *signature,
 			struct shash_desc *shash)
 {
@@ -45,10 +46,7 @@ int __cifs_calc_signature(struct smb_rqst *rqst,
 	struct kvec *iov = rqst->rq_iov;
 	int n_vec = rqst->rq_nvec;
 
-	if (n_vec < 2 || iov[0].iov_len != 4)
-		return -EIO;
-
-	for (i = 1; i < n_vec; i++) {
+	for (i = start; i < n_vec; i++) {
 		if (iov[i].iov_len == 0)
 			continue;
 		if (iov[i].iov_base == NULL) {
@@ -68,11 +66,12 @@ int __cifs_calc_signature(struct smb_rqst *rqst,
 
 	/* now hash over the rq_pages array */
 	for (i = 0; i < rqst->rq_npages; i++) {
-		void *kaddr = kmap(rqst->rq_pages[i]);
-		size_t len = rqst->rq_pagesz;
+		void *kaddr;
+		unsigned int len, offset;
+
+		rqst_page_get_length(rqst, i, &len, &offset);
 
-		if (i == rqst->rq_npages - 1)
-			len = rqst->rq_tailsz;
+		kaddr = (char *) kmap(rqst->rq_pages[i]) + offset;
 
 		crypto_shash_update(shash, kaddr, len);
 
@@ -119,7 +118,7 @@ static int cifs_calc_signature(struct smb_rqst *rqst,
 		return rc;
 	}
 
-	return __cifs_calc_signature(rqst, server, signature,
+	return __cifs_calc_signature(rqst, 1, server, signature,
 				     &server->secmech.sdescmd5->shash);
 }
 

fs/cifs/cifsfs.c

@@ -698,8 +698,8 @@ static int cifs_set_super(struct super_block *sb, void *data)
 }
 
 static struct dentry *
-cifs_do_mount(struct file_system_type *fs_type,
-	      int flags, const char *dev_name, void *data)
+cifs_smb3_do_mount(struct file_system_type *fs_type,
+	      int flags, const char *dev_name, void *data, bool is_smb3)
 {
 	int rc;
 	struct super_block *sb;
@@ -710,7 +710,7 @@ cifs_do_mount(struct file_system_type *fs_type,
 
 	cifs_dbg(FYI, "Devname: %s flags: %d\n", dev_name, flags);
 
-	volume_info = cifs_get_volume_info((char *)data, dev_name);
+	volume_info = cifs_get_volume_info((char *)data, dev_name, is_smb3);
 	if (IS_ERR(volume_info))
 		return ERR_CAST(volume_info);
 
@@ -790,6 +790,20 @@ cifs_do_mount(struct file_system_type *fs_type,
 	goto out;
 }
 
+static struct dentry *
+smb3_do_mount(struct file_system_type *fs_type,
+	      int flags, const char *dev_name, void *data)
+{
+	return cifs_smb3_do_mount(fs_type, flags, dev_name, data, true);
+}
+
+static struct dentry *
+cifs_do_mount(struct file_system_type *fs_type,
+	      int flags, const char *dev_name, void *data)
+{
+	return cifs_smb3_do_mount(fs_type, flags, dev_name, data, false);
+}
+
 static ssize_t
 cifs_loose_read_iter(struct kiocb *iocb, struct iov_iter *iter)
 {
@@ -925,7 +939,7 @@ MODULE_ALIAS_FS("cifs");
 static struct file_system_type smb3_fs_type = {
 	.owner = THIS_MODULE,
 	.name = "smb3",
-	.mount = cifs_do_mount,
+	.mount = smb3_do_mount,
 	.kill_sb = cifs_kill_sb,
 	/*  .fs_flags */
 };

fs/cifs/cifsglob.h

@@ -1019,6 +1019,12 @@ tlink_tcon(struct tcon_link *tlink)
 	return tlink->tl_tcon;
 }
 
+static inline struct tcon_link *
+cifs_sb_master_tlink(struct cifs_sb_info *cifs_sb)
+{
+	return cifs_sb->master_tlink;
+}
+
 extern void cifs_put_tlink(struct tcon_link *tlink);
 
 static inline struct tcon_link *

fs/cifs/cifsproto.h

@@ -211,7 +211,7 @@ extern int cifs_setup_cifs_sb(struct smb_vol *pvolume_info,
 extern int cifs_match_super(struct super_block *, void *);
 extern void cifs_cleanup_volume_info(struct smb_vol *pvolume_info);
 extern struct smb_vol *cifs_get_volume_info(char *mount_data,
-					    const char *devname);
+					    const char *devname, bool is_smb3);
 extern int cifs_mount(struct cifs_sb_info *, struct smb_vol *);
 extern void cifs_umount(struct cifs_sb_info *);
 extern void cifs_mark_open_files_invalid(struct cifs_tcon *tcon);
@@ -544,7 +544,7 @@ int cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 			   struct cifs_sb_info *cifs_sb,
 			   const unsigned char *path, char *pbuf,
 			   unsigned int *pbytes_written);
-int __cifs_calc_signature(struct smb_rqst *rqst,
+int __cifs_calc_signature(struct smb_rqst *rqst, int start,
 			struct TCP_Server_Info *server, char *signature,
 			struct shash_desc *shash);
 enum securityEnum cifs_select_sectype(struct TCP_Server_Info *,
@@ -557,4 +557,7 @@ int cifs_alloc_hash(const char *name, struct crypto_shash **shash,
 		    struct sdesc **sdesc);
 void cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc);
 
+extern void rqst_page_get_length(struct smb_rqst *rqst, unsigned int page,
+				unsigned int *len, unsigned int *offset);
+
 #endif			/* _CIFSPROTO_H */

fs/cifs/connect.c

@@ -320,7 +320,7 @@ static int generic_ip_connect(struct TCP_Server_Info *server);
 static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink);
 static void cifs_prune_tlinks(struct work_struct *work);
 static int cifs_setup_volume_info(struct smb_vol *volume_info, char *mount_data,
-					const char *devname);
+					const char *devname, bool is_smb3);
 
 /*
  * cifs tcp session reconnection
@@ -1166,7 +1166,7 @@ cifs_parse_cache_flavor(char *value, struct smb_vol *vol)
 }
 
 static int
-cifs_parse_smb_version(char *value, struct smb_vol *vol)
+cifs_parse_smb_version(char *value, struct smb_vol *vol, bool is_smb3)
 {
 	substring_t args[MAX_OPT_ARGS];
 
@@ -1176,6 +1176,10 @@ cifs_parse_smb_version(char *value, struct smb_vol *vol)
 			cifs_dbg(VFS, "mount with legacy dialect disabled\n");
 			return 1;
 		}
+		if (is_smb3) {
+			cifs_dbg(VFS, "vers=1.0 (cifs) not permitted when mounting with smb3\n");
+			return 1;
+		}
 		vol->ops = &smb1_operations;
 		vol->vals = &smb1_values;
 		break;
@@ -1184,6 +1188,10 @@ cifs_parse_smb_version(char *value, struct smb_vol *vol)
 			cifs_dbg(VFS, "mount with legacy dialect disabled\n");
 			return 1;
 		}
+		if (is_smb3) {
+			cifs_dbg(VFS, "vers=2.0 not permitted when mounting with smb3\n");
+			return 1;
+		}
 		vol->ops = &smb20_operations;
 		vol->vals = &smb20_values;
 		break;
@@ -1272,7 +1280,7 @@ cifs_parse_devname(const char *devname, struct smb_vol *vol)
 
 static int
 cifs_parse_mount_options(const char *mountdata, const char *devname,
-			 struct smb_vol *vol)
+			 struct smb_vol *vol, bool is_smb3)
 {
 	char *data, *end;
 	char *mountdata_copy = NULL, *options;
@@ -1985,7 +1993,7 @@ cifs_parse_mount_options(const char *mountdata, const char *devname,
 			if (string == NULL)
 				goto out_nomem;
 
-			if (cifs_parse_smb_version(string, vol) != 0)
+			if (cifs_parse_smb_version(string, vol, is_smb3) != 0)
 				goto cifs_parse_mount_err;
 			got_version = true;
 			break;
@@ -3116,12 +3124,6 @@ cifs_put_tlink(struct tcon_link *tlink)
 	return;
 }
 
-static inline struct tcon_link *
-cifs_sb_master_tlink(struct cifs_sb_info *cifs_sb)
-{
-	return cifs_sb->master_tlink;
-}
-
 static int
 compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
 {
@@ -3803,7 +3805,7 @@ expand_dfs_referral(const unsigned int xid, struct cifs_ses *ses,
 		} else {
 			cleanup_volume_info_contents(volume_info);
 			rc = cifs_setup_volume_info(volume_info, mdata,
-							fake_devname);
+							fake_devname, false);
 		}
 		kfree(fake_devname);
 		kfree(cifs_sb->mountdata);
@@ -3816,11 +3818,11 @@ expand_dfs_referral(const unsigned int xid, struct cifs_ses *ses,
 
 static int
 cifs_setup_volume_info(struct smb_vol *volume_info, char *mount_data,
-			const char *devname)
+			const char *devname, bool is_smb3)
 {
 	int rc = 0;
 
-	if (cifs_parse_mount_options(mount_data, devname, volume_info))
+	if (cifs_parse_mount_options(mount_data, devname, volume_info, is_smb3))
 		return -EINVAL;
 
 	if (volume_info->nullauth) {
@@ -3854,7 +3856,7 @@ cifs_setup_volume_info(struct smb_vol *volume_info, char *mount_data,
 }
 
 struct smb_vol *
-cifs_get_volume_info(char *mount_data, const char *devname)
+cifs_get_volume_info(char *mount_data, const char *devname, bool is_smb3)
 {
 	int rc;
 	struct smb_vol *volume_info;
@@ -3863,7 +3865,7 @@ cifs_get_volume_info(char *mount_data, const char *devname)
 	if (!volume_info)
 		return ERR_PTR(-ENOMEM);
 
-	rc = cifs_setup_volume_info(volume_info, mount_data, devname);
+	rc = cifs_setup_volume_info(volume_info, mount_data, devname, is_smb3);
 	if (rc) {
 		cifs_cleanup_volume_info(volume_info);
 		volume_info = ERR_PTR(rc);

fs/cifs/link.c

@@ -421,7 +421,8 @@ smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 		return  -ENOMEM;
 	}
 
-	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL);
+	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL,
+		       NULL);
 	if (rc)
 		goto qmf_out_open_fail;
 
@@ -478,7 +479,8 @@ smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 	oparms.fid = &fid;
 	oparms.reconnect = false;
 
-	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL);
+	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
+		       NULL);
 	if (rc) {
 		kfree(utf16_path);
 		return rc;

fs/cifs/misc.c

@@ -905,3 +905,20 @@ cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc)
 		crypto_free_shash(*shash);
 	*shash = NULL;
 }
+
+/**
+ * rqst_page_get_length - obtain the length and offset for a page in smb_rqst
+ * Input: rqst - a smb_rqst, page - a page index for rqst
+ * Output: *len - the length for this page, *offset - the offset for this page
+ */
+void rqst_page_get_length(struct smb_rqst *rqst, unsigned int page,
+				unsigned int *len, unsigned int *offset)
+{
+	*len = rqst->rq_pagesz;
+	*offset = (page == 0) ? rqst->rq_offset : 0;
+
+	if (rqst->rq_npages == 1 || page == rqst->rq_npages-1)
+		*len = rqst->rq_tailsz;
+	else if (page == 0)
+		*len = rqst->rq_pagesz - rqst->rq_offset;
+}

fs/cifs/smb2file.c

@@ -64,7 +64,8 @@ smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms,
 	if (oparms->tcon->ses->server->capabilities & SMB2_GLOBAL_CAP_LEASING)
 		memcpy(smb2_oplock + 1, fid->lease_key, SMB2_LEASE_KEY_SIZE);
 
-	rc = SMB2_open(xid, oparms, smb2_path, smb2_oplock, smb2_data, NULL);
+	rc = SMB2_open(xid, oparms, smb2_path, smb2_oplock, smb2_data, NULL,
+		       NULL);
 	if (rc)
 		goto out;
 

fs/cifs/smb2inode.c

@@ -71,7 +71,8 @@ smb2_open_op_close(const unsigned int xid, struct cifs_tcon *tcon,
 		oparms.fid = &fid;
 		oparms.reconnect = false;
 
-		rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL);
+		rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
+			       NULL);
 		if (rc) {
 			kfree(utf16_path);
 			return rc;

fs/cifs/smb2misc.c

@@ -453,8 +453,10 @@ cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
 		start_of_path = from + 1;
 #ifdef CONFIG_CIFS_SMB311
 	/* SMB311 POSIX extensions paths do not include leading slash */
-	else if (cifs_sb_master_tcon(cifs_sb)->posix_extensions)
+	else if (cifs_sb_master_tlink(cifs_sb) &&
+		 cifs_sb_master_tcon(cifs_sb)->posix_extensions) {
 		start_of_path = from + 1;
+	}
 #endif /* 311 */
 	else
 		start_of_path = from;