1 files changed, 63 insertions, 143 deletions

diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index 852aa00ec729..bd374feeccaa 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -1,22 +1,9 @@
+// SPDX-License-Identifier: LGPL-2.1
 /*
- *   fs/cifs/link.c
  *
  *   Copyright (C) International Business Machines  Corp., 2002,2008
  *   Author(s): Steve French (sfrench@us.ibm.com)
  *
- *   This library is free software; you can redistribute it and/or modify
- *   it under the terms of the GNU Lesser General Public License as published
- *   by the Free Software Foundation; either version 2.1 of the License, or
- *   (at your option) any later version.
- *
- *   This library is distributed in the hope that it will be useful,
- *   but WITHOUT ANY WARRANTY; without even the implied warranty of
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
- *   the GNU Lesser General Public License for more details.
- *
- *   You should have received a copy of the GNU Lesser General Public License
- *   along with this library; if not, write to the Free Software
- *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */
 #include <linux/fs.h>
 #include <linux/stat.h>
@@ -30,6 +17,7 @@
 #include "cifs_fs_sb.h"
 #include "cifs_unicode.h"
 #include "smb2proto.h"
+#include "cifs_ioctl.h"
 
 /*
  * M-F Symlink Functions - Begin
@@ -50,29 +38,28 @@ static int
 symlink_hash(unsigned int link_len, const char *link_str, u8 *md5_hash)
 {
 	int rc;
-	struct crypto_shash *md5 = NULL;
-	struct sdesc *sdescmd5 = NULL;
+	struct shash_desc *md5 = NULL;
 
-	rc = cifs_alloc_hash("md5", &md5, &sdescmd5);
+	rc = cifs_alloc_hash("md5", &md5);
 	if (rc)
 		goto symlink_hash_err;
 
-	rc = crypto_shash_init(&sdescmd5->shash);
+	rc = crypto_shash_init(md5);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not init md5 shash\n", __func__);
 		goto symlink_hash_err;
 	}
-	rc = crypto_shash_update(&sdescmd5->shash, link_str, link_len);
+	rc = crypto_shash_update(md5, link_str, link_len);
 	if (rc) {
 		cifs_dbg(VFS, "%s: Could not update with link_str\n", __func__);
 		goto symlink_hash_err;
 	}
-	rc = crypto_shash_final(&sdescmd5->shash, md5_hash);
+	rc = crypto_shash_final(md5, md5_hash);
 	if (rc)
 		cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
 
 symlink_hash_err:
-	cifs_free_hash(&md5, &sdescmd5);
+	cifs_free_hash(&md5);
 	return rc;
 }
 
@@ -97,6 +84,9 @@ parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
 	if (rc != 1)
 		return -EINVAL;
 
+	if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
+		return -EINVAL;
+
 	rc = symlink_hash(link_len, link_str, md5_hash);
 	if (rc) {
 		cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
@@ -211,40 +201,6 @@ out:
 	return rc;
 }
 
-static int
-query_mf_symlink(const unsigned int xid, struct cifs_tcon *tcon,
-		 struct cifs_sb_info *cifs_sb, const unsigned char *path,
-		 char **symlinkinfo)
-{
-	int rc;
-	u8 *buf = NULL;
-	unsigned int link_len = 0;
-	unsigned int bytes_read = 0;
-
-	buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
-	if (!buf)
-		return -ENOMEM;
-
-	if (tcon->ses->server->ops->query_mf_symlink)
-		rc = tcon->ses->server->ops->query_mf_symlink(xid, tcon,
-					      cifs_sb, path, buf, &bytes_read);
-	else
-		rc = -ENOSYS;
-
-	if (rc)
-		goto out;
-
-	if (bytes_read == 0) { /* not a symlink */
-		rc = -EINVAL;
-		goto out;
-	}
-
-	rc = parse_mf_symlink(buf, bytes_read, &link_len, symlinkinfo);
-out:
-	kfree(buf);
-	return rc;
-}
-
 int
 check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 		 struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
@@ -254,6 +210,7 @@ check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 	u8 *buf = NULL;
 	unsigned int link_len = 0;
 	unsigned int bytes_read = 0;
+	char *symlink = NULL;
 
 	if (!couldbe_mf_symlink(fattr))
 		/* it's not a symlink */
@@ -275,7 +232,7 @@ check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 	if (bytes_read == 0) /* not a symlink */
 		goto out;
 
-	rc = parse_mf_symlink(buf, bytes_read, &link_len, NULL);
+	rc = parse_mf_symlink(buf, bytes_read, &link_len, &symlink);
 	if (rc == -EINVAL) {
 		/* it's not a symlink */
 		rc = 0;
@@ -290,11 +247,13 @@ check_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 	fattr->cf_mode &= ~S_IFMT;
 	fattr->cf_mode |= S_IFLNK | S_IRWXU | S_IRWXG | S_IRWXO;
 	fattr->cf_dtype = DT_LNK;
+	fattr->cf_symlink_target = symlink;
 out:
 	kfree(buf);
 	return rc;
 }
 
+#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
 /*
  * SMB 1.0 Protocol specific functions
  */
@@ -308,7 +267,7 @@ cifs_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 	int oplock = 0;
 	struct cifs_fid fid;
 	struct cifs_open_parms oparms;
-	struct cifs_io_parms io_parms;
+	struct cifs_io_parms io_parms = {0};
 	int buf_type = CIFS_NO_BUFFER;
 	FILE_ALL_INFO file_info;
 
@@ -352,7 +311,7 @@ cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 	int oplock = 0;
 	struct cifs_fid fid;
 	struct cifs_open_parms oparms;
-	struct cifs_io_parms io_parms;
+	struct cifs_io_parms io_parms = {0};
 
 	oparms.tcon = tcon;
 	oparms.cifs_sb = cifs_sb;
@@ -377,6 +336,7 @@ cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 	CIFSSMBClose(xid, tcon, fid.netfid);
 	return rc;
 }
+#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
 
 /*
  * SMB 2.1/SMB3 Protocol specific functions
@@ -389,7 +349,7 @@ smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 	int rc;
 	struct cifs_fid fid;
 	struct cifs_open_parms oparms;
-	struct cifs_io_parms io_parms;
+	struct cifs_io_parms io_parms = {0};
 	int buf_type = CIFS_NO_BUFFER;
 	__le16 *utf16_path;
 	__u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
@@ -416,7 +376,7 @@ smb3_query_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 	}
 
 	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, pfile_info, NULL,
-		       NULL);
+		       NULL, NULL);
 	if (rc)
 		goto qmf_out_open_fail;
 
@@ -450,7 +410,7 @@ smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 	int rc;
 	struct cifs_fid fid;
 	struct cifs_open_parms oparms;
-	struct cifs_io_parms io_parms;
+	struct cifs_io_parms io_parms = {0};
 	__le16 *utf16_path;
 	__u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
 	struct kvec iov[2];
@@ -470,7 +430,7 @@ smb3_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
 	oparms.reconnect = false;
 
 	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL,
-		       NULL);
+		       NULL, NULL);
 	if (rc) {
 		kfree(utf16_path);
 		return rc;
@@ -510,33 +470,46 @@ cifs_hardlink(struct dentry *old_file, struct inode *inode,
 {
 	int rc = -EACCES;
 	unsigned int xid;
-	char *from_name = NULL;
-	char *to_name = NULL;
+	const char *from_name, *to_name;
+	void *page1, *page2;
 	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 	struct tcon_link *tlink;
 	struct cifs_tcon *tcon;
 	struct TCP_Server_Info *server;
 	struct cifsInodeInfo *cifsInode;
 
+	if (unlikely(cifs_forced_shutdown(cifs_sb)))
+		return -EIO;
+
 	tlink = cifs_sb_tlink(cifs_sb);
 	if (IS_ERR(tlink))
 		return PTR_ERR(tlink);
 	tcon = tlink_tcon(tlink);
 
 	xid = get_xid();
+	page1 = alloc_dentry_path();
+	page2 = alloc_dentry_path();
 
-	from_name = build_path_from_dentry(old_file);
-	to_name = build_path_from_dentry(direntry);
-	if ((from_name == NULL) || (to_name == NULL)) {
-		rc = -ENOMEM;
+	from_name = build_path_from_dentry(old_file, page1);
+	if (IS_ERR(from_name)) {
+		rc = PTR_ERR(from_name);
+		goto cifs_hl_exit;
+	}
+	to_name = build_path_from_dentry(direntry, page2);
+	if (IS_ERR(to_name)) {
+		rc = PTR_ERR(to_name);
 		goto cifs_hl_exit;
 	}
 
+#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
 	if (tcon->unix_ext)
 		rc = CIFSUnixCreateHardLink(xid, tcon, from_name, to_name,
 					    cifs_sb->local_nls,
 					    cifs_remap(cifs_sb));
 	else {
+#else
+	{
+#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
 		server = tcon->ses->server;
 		if (!server->ops->create_hardlink) {
 			rc = -ENOSYS;
@@ -587,90 +560,33 @@ cifs_hardlink(struct dentry *old_file, struct inode *inode,
 	}
 
 cifs_hl_exit:
-	kfree(from_name);
-	kfree(to_name);
+	free_dentry_path(page1);
+	free_dentry_path(page2);
 	free_xid(xid);
 	cifs_put_tlink(tlink);
 	return rc;
 }
 
-const char *
-cifs_get_link(struct dentry *direntry, struct inode *inode,
-	      struct delayed_call *done)
-{
-	int rc = -ENOMEM;
-	unsigned int xid;
-	char *full_path = NULL;
-	char *target_path = NULL;
-	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
-	struct tcon_link *tlink = NULL;
-	struct cifs_tcon *tcon;
-	struct TCP_Server_Info *server;
-
-	if (!direntry)
-		return ERR_PTR(-ECHILD);
-
-	xid = get_xid();
-
-	tlink = cifs_sb_tlink(cifs_sb);
-	if (IS_ERR(tlink)) {
-		free_xid(xid);
-		return ERR_CAST(tlink);
-	}
-	tcon = tlink_tcon(tlink);
-	server = tcon->ses->server;
-
-	full_path = build_path_from_dentry(direntry);
-	if (!full_path) {
-		free_xid(xid);
-		cifs_put_tlink(tlink);
-		return ERR_PTR(-ENOMEM);
-	}
-
-	cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);
-
-	rc = -EACCES;
-	/*
-	 * First try Minshall+French Symlinks, if configured
-	 * and fallback to UNIX Extensions Symlinks.
-	 */
-	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
-		rc = query_mf_symlink(xid, tcon, cifs_sb, full_path,
-				      &target_path);
-
-	if (rc != 0 && server->ops->query_symlink) {
-		struct cifsInodeInfo *cifsi = CIFS_I(inode);
-		bool reparse_point = false;
-
-		if (cifsi->cifsAttrs & ATTR_REPARSE)
-			reparse_point = true;
-
-		rc = server->ops->query_symlink(xid, tcon, cifs_sb, full_path,
-						&target_path, reparse_point);
-	}
-
-	kfree(full_path);
-	free_xid(xid);
-	cifs_put_tlink(tlink);
-	if (rc != 0) {
-		kfree(target_path);
-		return ERR_PTR(rc);
-	}
-	set_delayed_call(done, kfree_link, target_path);
-	return target_path;
-}
-
 int
-cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
+cifs_symlink(struct user_namespace *mnt_userns, struct inode *inode,
+	     struct dentry *direntry, const char *symname)
 {
 	int rc = -EOPNOTSUPP;
 	unsigned int xid;
 	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
 	struct tcon_link *tlink;
 	struct cifs_tcon *pTcon;
-	char *full_path = NULL;
+	const char *full_path;
+	void *page;
 	struct inode *newinode = NULL;
 
+	if (unlikely(cifs_forced_shutdown(cifs_sb)))
+		return -EIO;
+
+	page = alloc_dentry_path();
+	if (!page)
+		return -ENOMEM;
+
 	xid = get_xid();
 
 	tlink = cifs_sb_tlink(cifs_sb);
@@ -680,9 +596,9 @@ cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
 	}
 	pTcon = tlink_tcon(tlink);
 
-	full_path = build_path_from_dentry(direntry);
-	if (full_path == NULL) {
-		rc = -ENOMEM;
+	full_path = build_path_from_dentry(direntry, page);
+	if (IS_ERR(full_path)) {
+		rc = PTR_ERR(full_path);
 		goto symlink_exit;
 	}
 
@@ -692,16 +608,20 @@ cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
 	/* BB what if DFS and this volume is on different share? BB */
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS)
 		rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
+#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
 	else if (pTcon->unix_ext)
 		rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
 					   cifs_sb->local_nls,
 					   cifs_remap(cifs_sb));
+#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
 	/* else
 	   rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
 					cifs_sb_target->local_nls); */
 
 	if (rc == 0) {
-		if (pTcon->unix_ext)
+		if (pTcon->posix_extensions)
+			rc = smb311_posix_get_inode_info(&newinode, full_path, inode->i_sb, xid);
+		else if (pTcon->unix_ext)
 			rc = cifs_get_inode_info_unix(&newinode, full_path,
 						      inode->i_sb, xid);
 		else
@@ -716,7 +636,7 @@ cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
 		}
 	}
 symlink_exit:
-	kfree(full_path);
+	free_dentry_path(page);
 	cifs_put_tlink(tlink);
 	free_xid(xid);
 	return rc;