linux_dsm_epyc7002/fs/cifs/smb2inode.c
Aurelien Aptel 86f740f2ae cifs: fix rename() by ensuring source handle opened with DELETE bit
To rename a file in SMB2 we open it with the DELETE access and do a
special SetInfo on it. If the handle is missing the DELETE bit the
server will fail the SetInfo with STATUS_ACCESS_DENIED.

We currently try to reuse any existing opened handle we have with
cifs_get_writable_path(). That function looks for handles with WRITE
access but doesn't check for DELETE, making rename() fail if it finds
a handle to reuse. Simple reproducer below.

To select handles with the DELETE bit, this patch adds a flag argument
to cifs_get_writable_path() and find_writable_file() and the existing
'bool fsuid_only' argument is converted to a flag.

The cifsFileInfo struct only stores the UNIX open mode but not the
original SMB access flags. Since the DELETE bit is not mapped in that
mode, this patch stores the access mask in cifs_fid on file open,
which is accessible from cifsFileInfo.

Simple reproducer:

	#include <stdio.h>
	#include <stdlib.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <fcntl.h>
	#include <unistd.h>
	#define E(s) perror(s), exit(1)

	int main(int argc, char *argv[])
	{
		int fd, ret;
		if (argc != 3) {
			fprintf(stderr, "Usage: %s A B\n"
			"create&open A in write mode, "
			"rename A to B, close A\n", argv[0]);
			return 0;
		}

		fd = openat(AT_FDCWD, argv[1], O_WRONLY|O_CREAT|O_SYNC, 0666);
		if (fd == -1) E("openat()");

		ret = rename(argv[1], argv[2]);
		if (ret) E("rename()");

		ret = close(fd);
		if (ret) E("close()");

		return ret;
	}

$ gcc -o bugrename bugrename.c
$ ./bugrename /mnt/a /mnt/b
rename(): Permission denied

Fixes: 8de9e86c67 ("cifs: create a helper to find a writeable handle by path name")
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
2020-02-24 14:20:38 -06:00

631 lines
17 KiB
C

/*
* fs/cifs/smb2inode.c
*
* Copyright (C) International Business Machines Corp., 2002, 2011
* Etersoft, 2012
* Author(s): Pavel Shilovsky (pshilovsky@samba.org),
* 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>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include <asm/div64.h>
#include "cifsfs.h"
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
#include "cifs_unicode.h"
#include "fscache.h"
#include "smb2glob.h"
#include "smb2pdu.h"
#include "smb2proto.h"
static void
free_set_inf_compound(struct smb_rqst *rqst)
{
if (rqst[1].rq_iov)
SMB2_set_info_free(&rqst[1]);
if (rqst[2].rq_iov)
SMB2_close_free(&rqst[2]);
}
static int
smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon,
struct cifs_sb_info *cifs_sb, const char *full_path,
__u32 desired_access, __u32 create_disposition,
__u32 create_options, umode_t mode, void *ptr, int command,
struct cifsFileInfo *cfile)
{
int rc;
__le16 *utf16_path = NULL;
__u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
struct cifs_open_parms oparms;
struct cifs_fid fid;
struct cifs_ses *ses = tcon->ses;
int num_rqst = 0;
struct smb_rqst rqst[3];
int resp_buftype[3];
struct kvec rsp_iov[3];
struct kvec open_iov[SMB2_CREATE_IOV_SIZE];
struct kvec qi_iov[1];
struct kvec si_iov[SMB2_SET_INFO_IOV_SIZE];
struct kvec close_iov[1];
struct smb2_query_info_rsp *qi_rsp = NULL;
int flags = 0;
__u8 delete_pending[8] = {1, 0, 0, 0, 0, 0, 0, 0};
unsigned int size[2];
void *data[2];
struct smb2_file_rename_info rename_info;
struct smb2_file_link_info link_info;
int len;
if (smb3_encryption_required(tcon))
flags |= CIFS_TRANSFORM_REQ;
memset(rqst, 0, sizeof(rqst));
resp_buftype[0] = resp_buftype[1] = resp_buftype[2] = CIFS_NO_BUFFER;
memset(rsp_iov, 0, sizeof(rsp_iov));
/* We already have a handle so we can skip the open */
if (cfile)
goto after_open;
/* Open */
utf16_path = cifs_convert_path_to_utf16(full_path, cifs_sb);
if (!utf16_path) {
rc = -ENOMEM;
goto finished;
}
memset(&oparms, 0, sizeof(struct cifs_open_parms));
oparms.tcon = tcon;
oparms.desired_access = desired_access;
oparms.disposition = create_disposition;
oparms.create_options = cifs_create_options(cifs_sb, create_options);
oparms.fid = &fid;
oparms.reconnect = false;
oparms.mode = mode;
memset(&open_iov, 0, sizeof(open_iov));
rqst[num_rqst].rq_iov = open_iov;
rqst[num_rqst].rq_nvec = SMB2_CREATE_IOV_SIZE;
rc = SMB2_open_init(tcon, &rqst[num_rqst], &oplock, &oparms,
utf16_path);
kfree(utf16_path);
if (rc)
goto finished;
smb2_set_next_command(tcon, &rqst[num_rqst]);
after_open:
num_rqst++;
rc = 0;
/* Operation */
switch (command) {
case SMB2_OP_QUERY_INFO:
memset(&qi_iov, 0, sizeof(qi_iov));
rqst[num_rqst].rq_iov = qi_iov;
rqst[num_rqst].rq_nvec = 1;
if (cfile)
rc = SMB2_query_info_init(tcon, &rqst[num_rqst],
cfile->fid.persistent_fid,
cfile->fid.volatile_fid,
FILE_ALL_INFORMATION,
SMB2_O_INFO_FILE, 0,
sizeof(struct smb2_file_all_info) +
PATH_MAX * 2, 0, NULL);
else {
rc = SMB2_query_info_init(tcon, &rqst[num_rqst],
COMPOUND_FID,
COMPOUND_FID,
FILE_ALL_INFORMATION,
SMB2_O_INFO_FILE, 0,
sizeof(struct smb2_file_all_info) +
PATH_MAX * 2, 0, NULL);
if (!rc) {
smb2_set_next_command(tcon, &rqst[num_rqst]);
smb2_set_related(&rqst[num_rqst]);
}
}
if (rc)
goto finished;
num_rqst++;
trace_smb3_query_info_compound_enter(xid, ses->Suid, tcon->tid,
full_path);
break;
case SMB2_OP_DELETE:
trace_smb3_delete_enter(xid, ses->Suid, tcon->tid, full_path);
break;
case SMB2_OP_MKDIR:
/*
* Directories are created through parameters in the
* SMB2_open() call.
*/
trace_smb3_mkdir_enter(xid, ses->Suid, tcon->tid, full_path);
break;
case SMB2_OP_RMDIR:
memset(&si_iov, 0, sizeof(si_iov));
rqst[num_rqst].rq_iov = si_iov;
rqst[num_rqst].rq_nvec = 1;
size[0] = 1; /* sizeof __u8 See MS-FSCC section 2.4.11 */
data[0] = &delete_pending[0];
rc = SMB2_set_info_init(tcon, &rqst[num_rqst], COMPOUND_FID,
COMPOUND_FID, current->tgid,
FILE_DISPOSITION_INFORMATION,
SMB2_O_INFO_FILE, 0, data, size);
if (rc)
goto finished;
smb2_set_next_command(tcon, &rqst[num_rqst]);
smb2_set_related(&rqst[num_rqst++]);
trace_smb3_rmdir_enter(xid, ses->Suid, tcon->tid, full_path);
break;
case SMB2_OP_SET_EOF:
memset(&si_iov, 0, sizeof(si_iov));
rqst[num_rqst].rq_iov = si_iov;
rqst[num_rqst].rq_nvec = 1;
size[0] = 8; /* sizeof __le64 */
data[0] = ptr;
rc = SMB2_set_info_init(tcon, &rqst[num_rqst], COMPOUND_FID,
COMPOUND_FID, current->tgid,
FILE_END_OF_FILE_INFORMATION,
SMB2_O_INFO_FILE, 0, data, size);
if (rc)
goto finished;
smb2_set_next_command(tcon, &rqst[num_rqst]);
smb2_set_related(&rqst[num_rqst++]);
trace_smb3_set_eof_enter(xid, ses->Suid, tcon->tid, full_path);
break;
case SMB2_OP_SET_INFO:
memset(&si_iov, 0, sizeof(si_iov));
rqst[num_rqst].rq_iov = si_iov;
rqst[num_rqst].rq_nvec = 1;
size[0] = sizeof(FILE_BASIC_INFO);
data[0] = ptr;
if (cfile)
rc = SMB2_set_info_init(tcon, &rqst[num_rqst],
cfile->fid.persistent_fid,
cfile->fid.volatile_fid, current->tgid,
FILE_BASIC_INFORMATION,
SMB2_O_INFO_FILE, 0, data, size);
else {
rc = SMB2_set_info_init(tcon, &rqst[num_rqst],
COMPOUND_FID,
COMPOUND_FID, current->tgid,
FILE_BASIC_INFORMATION,
SMB2_O_INFO_FILE, 0, data, size);
if (!rc) {
smb2_set_next_command(tcon, &rqst[num_rqst]);
smb2_set_related(&rqst[num_rqst]);
}
}
if (rc)
goto finished;
num_rqst++;
trace_smb3_set_info_compound_enter(xid, ses->Suid, tcon->tid,
full_path);
break;
case SMB2_OP_RENAME:
memset(&si_iov, 0, sizeof(si_iov));
rqst[num_rqst].rq_iov = si_iov;
rqst[num_rqst].rq_nvec = 2;
len = (2 * UniStrnlen((wchar_t *)ptr, PATH_MAX));
rename_info.ReplaceIfExists = 1;
rename_info.RootDirectory = 0;
rename_info.FileNameLength = cpu_to_le32(len);
size[0] = sizeof(struct smb2_file_rename_info);
data[0] = &rename_info;
size[1] = len + 2 /* null */;
data[1] = (__le16 *)ptr;
if (cfile)
rc = SMB2_set_info_init(tcon, &rqst[num_rqst],
cfile->fid.persistent_fid,
cfile->fid.volatile_fid,
current->tgid, FILE_RENAME_INFORMATION,
SMB2_O_INFO_FILE, 0, data, size);
else {
rc = SMB2_set_info_init(tcon, &rqst[num_rqst],
COMPOUND_FID, COMPOUND_FID,
current->tgid, FILE_RENAME_INFORMATION,
SMB2_O_INFO_FILE, 0, data, size);
if (!rc) {
smb2_set_next_command(tcon, &rqst[num_rqst]);
smb2_set_related(&rqst[num_rqst]);
}
}
if (rc)
goto finished;
num_rqst++;
trace_smb3_rename_enter(xid, ses->Suid, tcon->tid, full_path);
break;
case SMB2_OP_HARDLINK:
memset(&si_iov, 0, sizeof(si_iov));
rqst[num_rqst].rq_iov = si_iov;
rqst[num_rqst].rq_nvec = 2;
len = (2 * UniStrnlen((wchar_t *)ptr, PATH_MAX));
link_info.ReplaceIfExists = 0;
link_info.RootDirectory = 0;
link_info.FileNameLength = cpu_to_le32(len);
size[0] = sizeof(struct smb2_file_link_info);
data[0] = &link_info;
size[1] = len + 2 /* null */;
data[1] = (__le16 *)ptr;
rc = SMB2_set_info_init(tcon, &rqst[num_rqst], COMPOUND_FID,
COMPOUND_FID, current->tgid,
FILE_LINK_INFORMATION,
SMB2_O_INFO_FILE, 0, data, size);
if (rc)
goto finished;
smb2_set_next_command(tcon, &rqst[num_rqst]);
smb2_set_related(&rqst[num_rqst++]);
trace_smb3_hardlink_enter(xid, ses->Suid, tcon->tid, full_path);
break;
default:
cifs_dbg(VFS, "Invalid command\n");
rc = -EINVAL;
}
if (rc)
goto finished;
/* We already have a handle so we can skip the close */
if (cfile)
goto after_close;
/* Close */
memset(&close_iov, 0, sizeof(close_iov));
rqst[num_rqst].rq_iov = close_iov;
rqst[num_rqst].rq_nvec = 1;
rc = SMB2_close_init(tcon, &rqst[num_rqst], COMPOUND_FID,
COMPOUND_FID, false);
smb2_set_related(&rqst[num_rqst]);
if (rc)
goto finished;
after_close:
num_rqst++;
if (cfile) {
cifsFileInfo_put(cfile);
cfile = NULL;
rc = compound_send_recv(xid, ses, flags, num_rqst - 2,
&rqst[1], &resp_buftype[1],
&rsp_iov[1]);
} else
rc = compound_send_recv(xid, ses, flags, num_rqst,
rqst, resp_buftype,
rsp_iov);
finished:
if (cfile)
cifsFileInfo_put(cfile);
SMB2_open_free(&rqst[0]);
if (rc == -EREMCHG) {
printk_once(KERN_WARNING "server share %s deleted\n",
tcon->treeName);
tcon->need_reconnect = true;
}
switch (command) {
case SMB2_OP_QUERY_INFO:
if (rc == 0) {
qi_rsp = (struct smb2_query_info_rsp *)
rsp_iov[1].iov_base;
rc = smb2_validate_and_copy_iov(
le16_to_cpu(qi_rsp->OutputBufferOffset),
le32_to_cpu(qi_rsp->OutputBufferLength),
&rsp_iov[1], sizeof(struct smb2_file_all_info),
ptr);
}
if (rqst[1].rq_iov)
SMB2_query_info_free(&rqst[1]);
if (rqst[2].rq_iov)
SMB2_close_free(&rqst[2]);
if (rc)
trace_smb3_query_info_compound_err(xid, ses->Suid,
tcon->tid, rc);
else
trace_smb3_query_info_compound_done(xid, ses->Suid,
tcon->tid);
break;
case SMB2_OP_DELETE:
if (rc)
trace_smb3_delete_err(xid, ses->Suid, tcon->tid, rc);
else
trace_smb3_delete_done(xid, ses->Suid, tcon->tid);
if (rqst[1].rq_iov)
SMB2_close_free(&rqst[1]);
break;
case SMB2_OP_MKDIR:
if (rc)
trace_smb3_mkdir_err(xid, ses->Suid, tcon->tid, rc);
else
trace_smb3_mkdir_done(xid, ses->Suid, tcon->tid);
if (rqst[1].rq_iov)
SMB2_close_free(&rqst[1]);
break;
case SMB2_OP_HARDLINK:
if (rc)
trace_smb3_hardlink_err(xid, ses->Suid, tcon->tid, rc);
else
trace_smb3_hardlink_done(xid, ses->Suid, tcon->tid);
free_set_inf_compound(rqst);
break;
case SMB2_OP_RENAME:
if (rc)
trace_smb3_rename_err(xid, ses->Suid, tcon->tid, rc);
else
trace_smb3_rename_done(xid, ses->Suid, tcon->tid);
free_set_inf_compound(rqst);
break;
case SMB2_OP_RMDIR:
if (rc)
trace_smb3_rmdir_err(xid, ses->Suid, tcon->tid, rc);
else
trace_smb3_rmdir_done(xid, ses->Suid, tcon->tid);
free_set_inf_compound(rqst);
break;
case SMB2_OP_SET_EOF:
if (rc)
trace_smb3_set_eof_err(xid, ses->Suid, tcon->tid, rc);
else
trace_smb3_set_eof_done(xid, ses->Suid, tcon->tid);
free_set_inf_compound(rqst);
break;
case SMB2_OP_SET_INFO:
if (rc)
trace_smb3_set_info_compound_err(xid, ses->Suid,
tcon->tid, rc);
else
trace_smb3_set_info_compound_done(xid, ses->Suid,
tcon->tid);
free_set_inf_compound(rqst);
break;
}
free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base);
free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base);
free_rsp_buf(resp_buftype[2], rsp_iov[2].iov_base);
return rc;
}
void
move_smb2_info_to_cifs(FILE_ALL_INFO *dst, struct smb2_file_all_info *src)
{
memcpy(dst, src, (size_t)(&src->CurrentByteOffset) - (size_t)src);
dst->CurrentByteOffset = src->CurrentByteOffset;
dst->Mode = src->Mode;
dst->AlignmentRequirement = src->AlignmentRequirement;
dst->IndexNumber1 = 0; /* we don't use it */
}
int
smb2_query_path_info(const unsigned int xid, struct cifs_tcon *tcon,
struct cifs_sb_info *cifs_sb, const char *full_path,
FILE_ALL_INFO *data, bool *adjust_tz, bool *symlink)
{
int rc;
struct smb2_file_all_info *smb2_data;
__u32 create_options = 0;
struct cifs_fid fid;
bool no_cached_open = tcon->nohandlecache;
struct cifsFileInfo *cfile;
*adjust_tz = false;
*symlink = false;
smb2_data = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
GFP_KERNEL);
if (smb2_data == NULL)
return -ENOMEM;
/* If it is a root and its handle is cached then use it */
if (!strlen(full_path) && !no_cached_open) {
rc = open_shroot(xid, tcon, cifs_sb, &fid);
if (rc)
goto out;
if (tcon->crfid.file_all_info_is_valid) {
move_smb2_info_to_cifs(data,
&tcon->crfid.file_all_info);
} else {
rc = SMB2_query_info(xid, tcon, fid.persistent_fid,
fid.volatile_fid, smb2_data);
if (!rc)
move_smb2_info_to_cifs(data, smb2_data);
}
close_shroot(&tcon->crfid);
goto out;
}
cifs_get_readable_path(tcon, full_path, &cfile);
rc = smb2_compound_op(xid, tcon, cifs_sb, full_path,
FILE_READ_ATTRIBUTES, FILE_OPEN, create_options,
ACL_NO_MODE, smb2_data, SMB2_OP_QUERY_INFO, cfile);
if (rc == -EOPNOTSUPP) {
*symlink = true;
create_options |= OPEN_REPARSE_POINT;
/* Failed on a symbolic link - query a reparse point info */
rc = smb2_compound_op(xid, tcon, cifs_sb, full_path,
FILE_READ_ATTRIBUTES, FILE_OPEN,
create_options, ACL_NO_MODE,
smb2_data, SMB2_OP_QUERY_INFO, NULL);
}
if (rc)
goto out;
move_smb2_info_to_cifs(data, smb2_data);
out:
kfree(smb2_data);
return rc;
}
int
smb2_mkdir(const unsigned int xid, struct inode *parent_inode, umode_t mode,
struct cifs_tcon *tcon, const char *name,
struct cifs_sb_info *cifs_sb)
{
return smb2_compound_op(xid, tcon, cifs_sb, name,
FILE_WRITE_ATTRIBUTES, FILE_CREATE,
CREATE_NOT_FILE, mode, NULL, SMB2_OP_MKDIR,
NULL);
}
void
smb2_mkdir_setinfo(struct inode *inode, const char *name,
struct cifs_sb_info *cifs_sb, struct cifs_tcon *tcon,
const unsigned int xid)
{
FILE_BASIC_INFO data;
struct cifsInodeInfo *cifs_i;
struct cifsFileInfo *cfile;
u32 dosattrs;
int tmprc;
memset(&data, 0, sizeof(data));
cifs_i = CIFS_I(inode);
dosattrs = cifs_i->cifsAttrs | ATTR_READONLY;
data.Attributes = cpu_to_le32(dosattrs);
cifs_get_writable_path(tcon, name, FIND_WR_ANY, &cfile);
tmprc = smb2_compound_op(xid, tcon, cifs_sb, name,
FILE_WRITE_ATTRIBUTES, FILE_CREATE,
CREATE_NOT_FILE, ACL_NO_MODE,
&data, SMB2_OP_SET_INFO, cfile);
if (tmprc == 0)
cifs_i->cifsAttrs = dosattrs;
}
int
smb2_rmdir(const unsigned int xid, struct cifs_tcon *tcon, const char *name,
struct cifs_sb_info *cifs_sb)
{
return smb2_compound_op(xid, tcon, cifs_sb, name, DELETE, FILE_OPEN,
CREATE_NOT_FILE, ACL_NO_MODE,
NULL, SMB2_OP_RMDIR, NULL);
}
int
smb2_unlink(const unsigned int xid, struct cifs_tcon *tcon, const char *name,
struct cifs_sb_info *cifs_sb)
{
return smb2_compound_op(xid, tcon, cifs_sb, name, DELETE, FILE_OPEN,
CREATE_DELETE_ON_CLOSE | OPEN_REPARSE_POINT,
ACL_NO_MODE, NULL, SMB2_OP_DELETE, NULL);
}
static int
smb2_set_path_attr(const unsigned int xid, struct cifs_tcon *tcon,
const char *from_name, const char *to_name,
struct cifs_sb_info *cifs_sb, __u32 access, int command,
struct cifsFileInfo *cfile)
{
__le16 *smb2_to_name = NULL;
int rc;
smb2_to_name = cifs_convert_path_to_utf16(to_name, cifs_sb);
if (smb2_to_name == NULL) {
rc = -ENOMEM;
goto smb2_rename_path;
}
rc = smb2_compound_op(xid, tcon, cifs_sb, from_name, access,
FILE_OPEN, 0, ACL_NO_MODE, smb2_to_name,
command, cfile);
smb2_rename_path:
kfree(smb2_to_name);
return rc;
}
int
smb2_rename_path(const unsigned int xid, struct cifs_tcon *tcon,
const char *from_name, const char *to_name,
struct cifs_sb_info *cifs_sb)
{
struct cifsFileInfo *cfile;
cifs_get_writable_path(tcon, from_name, FIND_WR_WITH_DELETE, &cfile);
return smb2_set_path_attr(xid, tcon, from_name, to_name,
cifs_sb, DELETE, SMB2_OP_RENAME, cfile);
}
int
smb2_create_hardlink(const unsigned int xid, struct cifs_tcon *tcon,
const char *from_name, const char *to_name,
struct cifs_sb_info *cifs_sb)
{
return smb2_set_path_attr(xid, tcon, from_name, to_name, cifs_sb,
FILE_READ_ATTRIBUTES, SMB2_OP_HARDLINK,
NULL);
}
int
smb2_set_path_size(const unsigned int xid, struct cifs_tcon *tcon,
const char *full_path, __u64 size,
struct cifs_sb_info *cifs_sb, bool set_alloc)
{
__le64 eof = cpu_to_le64(size);
return smb2_compound_op(xid, tcon, cifs_sb, full_path,
FILE_WRITE_DATA, FILE_OPEN, 0, ACL_NO_MODE,
&eof, SMB2_OP_SET_EOF, NULL);
}
int
smb2_set_file_info(struct inode *inode, const char *full_path,
FILE_BASIC_INFO *buf, const unsigned int xid)
{
struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
struct tcon_link *tlink;
int rc;
if ((buf->CreationTime == 0) && (buf->LastAccessTime == 0) &&
(buf->LastWriteTime == 0) && (buf->ChangeTime == 0) &&
(buf->Attributes == 0))
return 0; /* would be a no op, no sense sending this */
tlink = cifs_sb_tlink(cifs_sb);
if (IS_ERR(tlink))
return PTR_ERR(tlink);
rc = smb2_compound_op(xid, tlink_tcon(tlink), cifs_sb, full_path,
FILE_WRITE_ATTRIBUTES, FILE_OPEN,
0, ACL_NO_MODE, buf, SMB2_OP_SET_INFO, NULL);
cifs_put_tlink(tlink);
return rc;
}