linux-stable/fs/ksmbd/misc.c
Dan Carpenter 87ffb310d5 ksmbd: missing check for NULL in convert_to_nt_pathname()
The kmalloc() does not have a NULL check.  This code can be re-written
slightly cleaner to just use the kstrdup().

Fixes: 265fd1991c ("ksmbd: use LOOKUP_BENEATH to prevent the out of share access")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Acked-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-30 20:00:05 -05:00

331 lines
6.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2016 Namjae Jeon <linkinjeon@kernel.org>
* Copyright (C) 2018 Samsung Electronics Co., Ltd.
*/
#include <linux/kernel.h>
#include <linux/xattr.h>
#include <linux/fs.h>
#include "misc.h"
#include "smb_common.h"
#include "connection.h"
#include "vfs.h"
#include "mgmt/share_config.h"
/**
* match_pattern() - compare a string with a pattern which might include
* wildcard '*' and '?'
* TODO : implement consideration about DOS_DOT, DOS_QM and DOS_STAR
*
* @string: string to compare with a pattern
* @len: string length
* @pattern: pattern string which might include wildcard '*' and '?'
*
* Return: 0 if pattern matched with the string, otherwise non zero value
*/
int match_pattern(const char *str, size_t len, const char *pattern)
{
const char *s = str;
const char *p = pattern;
bool star = false;
while (*s && len) {
switch (*p) {
case '?':
s++;
len--;
p++;
break;
case '*':
star = true;
str = s;
if (!*++p)
return true;
pattern = p;
break;
default:
if (tolower(*s) == tolower(*p)) {
s++;
len--;
p++;
} else {
if (!star)
return false;
str++;
s = str;
p = pattern;
}
break;
}
}
if (*p == '*')
++p;
return !*p;
}
/*
* is_char_allowed() - check for valid character
* @ch: input character to be checked
*
* Return: 1 if char is allowed, otherwise 0
*/
static inline int is_char_allowed(char ch)
{
/* check for control chars, wildcards etc. */
if (!(ch & 0x80) &&
(ch <= 0x1f ||
ch == '?' || ch == '"' || ch == '<' ||
ch == '>' || ch == '|' || ch == '*'))
return 0;
return 1;
}
int ksmbd_validate_filename(char *filename)
{
while (*filename) {
char c = *filename;
filename++;
if (!is_char_allowed(c)) {
ksmbd_debug(VFS, "File name validation failed: 0x%x\n", c);
return -ENOENT;
}
}
return 0;
}
static int ksmbd_validate_stream_name(char *stream_name)
{
while (*stream_name) {
char c = *stream_name;
stream_name++;
if (c == '/' || c == ':' || c == '\\') {
pr_err("Stream name validation failed: %c\n", c);
return -ENOENT;
}
}
return 0;
}
int parse_stream_name(char *filename, char **stream_name, int *s_type)
{
char *stream_type;
char *s_name;
int rc = 0;
s_name = filename;
filename = strsep(&s_name, ":");
ksmbd_debug(SMB, "filename : %s, streams : %s\n", filename, s_name);
if (strchr(s_name, ':')) {
stream_type = s_name;
s_name = strsep(&stream_type, ":");
rc = ksmbd_validate_stream_name(s_name);
if (rc < 0) {
rc = -ENOENT;
goto out;
}
ksmbd_debug(SMB, "stream name : %s, stream type : %s\n", s_name,
stream_type);
if (!strncasecmp("$data", stream_type, 5))
*s_type = DATA_STREAM;
else if (!strncasecmp("$index_allocation", stream_type, 17))
*s_type = DIR_STREAM;
else
rc = -ENOENT;
}
*stream_name = s_name;
out:
return rc;
}
/**
* convert_to_nt_pathname() - extract and return windows path string
* whose share directory prefix was removed from file path
* @filename : unix filename
* @sharepath: share path string
*
* Return : windows path string or error
*/
char *convert_to_nt_pathname(char *filename)
{
char *ab_pathname;
if (strlen(filename) == 0)
filename = "\\";
ab_pathname = kstrdup(filename, GFP_KERNEL);
if (!ab_pathname)
return NULL;
ksmbd_conv_path_to_windows(ab_pathname);
return ab_pathname;
}
int get_nlink(struct kstat *st)
{
int nlink;
nlink = st->nlink;
if (S_ISDIR(st->mode))
nlink--;
return nlink;
}
void ksmbd_conv_path_to_unix(char *path)
{
strreplace(path, '\\', '/');
}
void ksmbd_strip_last_slash(char *path)
{
int len = strlen(path);
while (len && path[len - 1] == '/') {
path[len - 1] = '\0';
len--;
}
}
void ksmbd_conv_path_to_windows(char *path)
{
strreplace(path, '/', '\\');
}
/**
* ksmbd_extract_sharename() - get share name from tree connect request
* @treename: buffer containing tree name and share name
*
* Return: share name on success, otherwise error
*/
char *ksmbd_extract_sharename(char *treename)
{
char *name = treename;
char *dst;
char *pos = strrchr(name, '\\');
if (pos)
name = (pos + 1);
/* caller has to free the memory */
dst = kstrdup(name, GFP_KERNEL);
if (!dst)
return ERR_PTR(-ENOMEM);
return dst;
}
/**
* convert_to_unix_name() - convert windows name to unix format
* @path: name to be converted
* @tid: tree id of mathing share
*
* Return: converted name on success, otherwise NULL
*/
char *convert_to_unix_name(struct ksmbd_share_config *share, const char *name)
{
int no_slash = 0, name_len, path_len;
char *new_name;
if (name[0] == '/')
name++;
path_len = share->path_sz;
name_len = strlen(name);
new_name = kmalloc(path_len + name_len + 2, GFP_KERNEL);
if (!new_name)
return new_name;
memcpy(new_name, share->path, path_len);
if (new_name[path_len - 1] != '/') {
new_name[path_len] = '/';
no_slash = 1;
}
memcpy(new_name + path_len + no_slash, name, name_len);
path_len += name_len + no_slash;
new_name[path_len] = 0x00;
return new_name;
}
char *ksmbd_convert_dir_info_name(struct ksmbd_dir_info *d_info,
const struct nls_table *local_nls,
int *conv_len)
{
char *conv;
int sz = min(4 * d_info->name_len, PATH_MAX);
if (!sz)
return NULL;
conv = kmalloc(sz, GFP_KERNEL);
if (!conv)
return NULL;
/* XXX */
*conv_len = smbConvertToUTF16((__le16 *)conv, d_info->name,
d_info->name_len, local_nls, 0);
*conv_len *= 2;
/* We allocate buffer twice bigger than needed. */
conv[*conv_len] = 0x00;
conv[*conv_len + 1] = 0x00;
return conv;
}
/*
* Convert the NT UTC (based 1601-01-01, in hundred nanosecond units)
* into Unix UTC (based 1970-01-01, in seconds).
*/
struct timespec64 ksmbd_NTtimeToUnix(__le64 ntutc)
{
struct timespec64 ts;
/* Subtract the NTFS time offset, then convert to 1s intervals. */
s64 t = le64_to_cpu(ntutc) - NTFS_TIME_OFFSET;
u64 abs_t;
/*
* Unfortunately can not use normal 64 bit division on 32 bit arch, but
* the alternative, do_div, does not work with negative numbers so have
* to special case them
*/
if (t < 0) {
abs_t = -t;
ts.tv_nsec = do_div(abs_t, 10000000) * 100;
ts.tv_nsec = -ts.tv_nsec;
ts.tv_sec = -abs_t;
} else {
abs_t = t;
ts.tv_nsec = do_div(abs_t, 10000000) * 100;
ts.tv_sec = abs_t;
}
return ts;
}
/* Convert the Unix UTC into NT UTC. */
inline u64 ksmbd_UnixTimeToNT(struct timespec64 t)
{
/* Convert to 100ns intervals and then add the NTFS time offset. */
return (u64)t.tv_sec * 10000000 + t.tv_nsec / 100 + NTFS_TIME_OFFSET;
}
inline long long ksmbd_systime(void)
{
struct timespec64 ts;
ktime_get_real_ts64(&ts);
return ksmbd_UnixTimeToNT(ts);
}