Commit 265fd199 authored by Hyunchul Lee's avatar Hyunchul Lee Committed by Steve French

ksmbd: use LOOKUP_BENEATH to prevent the out of share access

instead of removing '..' in a given path, call
kern_path with LOOKUP_BENEATH flag to prevent
the out of share access.

ran various test on this:
smb2-cat-async smb://127.0.0.1/homes/../out_of_share
smb2-cat-async smb://127.0.0.1/homes/foo/../../out_of_share
smbclient //127.0.0.1/homes -c "mkdir ../foo2"
smbclient //127.0.0.1/homes -c "rename bar ../bar"

Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Cc: Ralph Boehme <slow@samba.org>
Tested-by: default avatarSteve French <smfrench@gmail.com>
Tested-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
Acked-by: default avatarNamjae Jeon <linkinjeon@kernel.org>
Signed-off-by: default avatarHyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 4ea47798
......@@ -158,25 +158,21 @@ int parse_stream_name(char *filename, char **stream_name, int *s_type)
* Return : windows path string or error
*/
char *convert_to_nt_pathname(char *filename, char *sharepath)
char *convert_to_nt_pathname(char *filename)
{
char *ab_pathname;
int len, name_len;
name_len = strlen(filename);
ab_pathname = kmalloc(name_len, GFP_KERNEL);
if (!ab_pathname)
return NULL;
if (strlen(filename) == 0) {
ab_pathname = kmalloc(2, GFP_KERNEL);
ab_pathname[0] = '\\';
ab_pathname[1] = '\0';
} else {
ab_pathname = kstrdup(filename, GFP_KERNEL);
if (!ab_pathname)
return NULL;
len = strlen(sharepath);
if (!strncmp(filename, sharepath, len) && name_len != len) {
strscpy(ab_pathname, &filename[len], name_len);
ksmbd_conv_path_to_windows(ab_pathname);
}
return ab_pathname;
}
......@@ -191,77 +187,19 @@ int get_nlink(struct kstat *st)
return nlink;
}
char *ksmbd_conv_path_to_unix(char *path)
void ksmbd_conv_path_to_unix(char *path)
{
size_t path_len, remain_path_len, out_path_len;
char *out_path, *out_next;
int i, pre_dotdot_cnt = 0, slash_cnt = 0;
bool is_last;
strreplace(path, '\\', '/');
path_len = strlen(path);
remain_path_len = path_len;
if (path_len == 0)
return ERR_PTR(-EINVAL);
out_path = kzalloc(path_len + 2, GFP_KERNEL);
if (!out_path)
return ERR_PTR(-ENOMEM);
out_path_len = 0;
out_next = out_path;
do {
char *name = path + path_len - remain_path_len;
char *next = strchrnul(name, '/');
size_t name_len = next - name;
is_last = !next[0];
if (name_len == 2 && name[0] == '.' && name[1] == '.') {
pre_dotdot_cnt++;
/* handle the case that path ends with "/.." */
if (is_last)
goto follow_dotdot;
} else {
if (pre_dotdot_cnt) {
follow_dotdot:
slash_cnt = 0;
for (i = out_path_len - 1; i >= 0; i--) {
if (out_path[i] == '/' &&
++slash_cnt == pre_dotdot_cnt + 1)
break;
}
if (i < 0 &&
slash_cnt != pre_dotdot_cnt) {
kfree(out_path);
return ERR_PTR(-EINVAL);
}
out_next = &out_path[i+1];
*out_next = '\0';
out_path_len = i + 1;
}
}
void ksmbd_strip_last_slash(char *path)
{
int len = strlen(path);
if (name_len != 0 &&
!(name_len == 1 && name[0] == '.') &&
!(name_len == 2 && name[0] == '.' && name[1] == '.')) {
next[0] = '\0';
sprintf(out_next, "%s/", name);
out_next += name_len + 1;
out_path_len += name_len + 1;
next[0] = '/';
}
pre_dotdot_cnt = 0;
while (len && path[len - 1] == '/') {
path[len - 1] = '\0';
len--;
}
remain_path_len -= name_len + 1;
} while (!is_last);
if (out_path_len > 0)
out_path[out_path_len-1] = '\0';
path[path_len] = '\0';
return out_path;
}
void ksmbd_conv_path_to_windows(char *path)
......@@ -298,7 +236,7 @@ char *ksmbd_extract_sharename(char *treename)
*
* Return: converted name on success, otherwise NULL
*/
char *convert_to_unix_name(struct ksmbd_share_config *share, char *name)
char *convert_to_unix_name(struct ksmbd_share_config *share, const char *name)
{
int no_slash = 0, name_len, path_len;
char *new_name;
......
......@@ -14,12 +14,13 @@ struct ksmbd_file;
int match_pattern(const char *str, size_t len, const char *pattern);
int ksmbd_validate_filename(char *filename);
int parse_stream_name(char *filename, char **stream_name, int *s_type);
char *convert_to_nt_pathname(char *filename, char *sharepath);
char *convert_to_nt_pathname(char *filename);
int get_nlink(struct kstat *st);
char *ksmbd_conv_path_to_unix(char *path);
void ksmbd_conv_path_to_unix(char *path);
void ksmbd_strip_last_slash(char *path);
void ksmbd_conv_path_to_windows(char *path);
char *ksmbd_extract_sharename(char *treename);
char *convert_to_unix_name(struct ksmbd_share_config *share, char *name);
char *convert_to_unix_name(struct ksmbd_share_config *share, const char *name);
#define KSMBD_DIR_INFO_ALIGNMENT 8
struct ksmbd_dir_info;
......
......@@ -634,7 +634,7 @@ static char *
smb2_get_name(struct ksmbd_share_config *share, const char *src,
const int maxlen, struct nls_table *local_nls)
{
char *name, *norm_name, *unixname;
char *name;
name = smb_strndup_from_utf16(src, maxlen, 1, local_nls);
if (IS_ERR(name)) {
......@@ -642,23 +642,9 @@ smb2_get_name(struct ksmbd_share_config *share, const char *src,
return name;
}
/* change it to absolute unix name */
norm_name = ksmbd_conv_path_to_unix(name);
if (IS_ERR(norm_name)) {
kfree(name);
return norm_name;
}
kfree(name);
unixname = convert_to_unix_name(share, norm_name);
kfree(norm_name);
if (!unixname) {
pr_err("can not convert absolute name\n");
return ERR_PTR(-ENOMEM);
}
ksmbd_debug(SMB, "absolute name = %s\n", unixname);
return unixname;
ksmbd_conv_path_to_unix(name);
ksmbd_strip_last_slash(name);
return name;
}
int setup_async_work(struct ksmbd_work *work, void (*fn)(void **), void **arg)
......@@ -2352,7 +2338,7 @@ static int smb2_creat(struct ksmbd_work *work, struct path *path, char *name,
return rc;
}
rc = ksmbd_vfs_kern_path(name, 0, path, 0);
rc = ksmbd_vfs_kern_path(work, name, 0, path, 0);
if (rc) {
pr_err("cannot get linux path (%s), err = %d\n",
name, rc);
......@@ -2427,7 +2413,7 @@ int smb2_open(struct ksmbd_work *work)
struct oplock_info *opinfo;
__le32 *next_ptr = NULL;
int req_op_level = 0, open_flags = 0, may_flags = 0, file_info = 0;
int rc = 0, len = 0;
int rc = 0;
int contxt_cnt = 0, query_disk_id = 0;
int maximal_access_ctxt = 0, posix_ctxt = 0;
int s_type = 0;
......@@ -2499,17 +2485,11 @@ int smb2_open(struct ksmbd_work *work)
goto err_out1;
}
} else {
len = strlen(share->path);
ksmbd_debug(SMB, "share path len %d\n", len);
name = kmalloc(len + 1, GFP_KERNEL);
name = kstrdup("", GFP_KERNEL);
if (!name) {
rsp->hdr.Status = STATUS_NO_MEMORY;
rc = -ENOMEM;
goto err_out1;
}
memcpy(name, share->path, len);
*(name + len) = '\0';
}
req_op_level = req->RequestedOplockLevel;
......@@ -2632,7 +2612,7 @@ int smb2_open(struct ksmbd_work *work)
goto err_out1;
}
rc = ksmbd_vfs_kern_path(name, LOOKUP_NO_SYMLINKS, &path, 1);
rc = ksmbd_vfs_kern_path(work, name, LOOKUP_NO_SYMLINKS, &path, 1);
if (!rc) {
if (req->CreateOptions & FILE_DELETE_ON_CLOSE_LE) {
/*
......@@ -2661,11 +2641,8 @@ int smb2_open(struct ksmbd_work *work)
}
if (rc) {
if (rc == -EACCES) {
ksmbd_debug(SMB,
"User does not have right permission\n");
if (rc != -ENOENT)
goto err_out;
}
ksmbd_debug(SMB, "can not get linux path for %s, rc = %d\n",
name, rc);
rc = 0;
......@@ -3161,7 +3138,7 @@ int smb2_open(struct ksmbd_work *work)
rsp->hdr.Status = STATUS_INVALID_PARAMETER;
else if (rc == -EOPNOTSUPP)
rsp->hdr.Status = STATUS_NOT_SUPPORTED;
else if (rc == -EACCES || rc == -ESTALE)
else if (rc == -EACCES || rc == -ESTALE || rc == -EXDEV)
rsp->hdr.Status = STATUS_ACCESS_DENIED;
else if (rc == -ENOENT)
rsp->hdr.Status = STATUS_OBJECT_NAME_INVALID;
......@@ -4277,8 +4254,7 @@ static int get_file_all_info(struct ksmbd_work *work,
return -EACCES;
}
filename = convert_to_nt_pathname(fp->filename,
work->tcon->share_conf->path);
filename = convert_to_nt_pathname(fp->filename);
if (!filename)
return -ENOMEM;
......@@ -4733,7 +4709,7 @@ static int smb2_get_info_filesystem(struct ksmbd_work *work,
int rc = 0, len;
int fs_infoclass_size = 0;
rc = ksmbd_vfs_kern_path(share->path, LOOKUP_NO_SYMLINKS, &path, 0);
rc = kern_path(share->path, LOOKUP_NO_SYMLINKS, &path);
if (rc) {
pr_err("cannot create vfs path\n");
return -EIO;
......@@ -5282,7 +5258,7 @@ static int smb2_rename(struct ksmbd_work *work,
goto out;
len = strlen(new_name);
if (new_name[len - 1] != '/') {
if (len > 0 && new_name[len - 1] != '/') {
pr_err("not allow base filename in rename\n");
rc = -ESHARE;
goto out;
......@@ -5310,11 +5286,14 @@ static int smb2_rename(struct ksmbd_work *work,
}
ksmbd_debug(SMB, "new name %s\n", new_name);
rc = ksmbd_vfs_kern_path(new_name, LOOKUP_NO_SYMLINKS, &path, 1);
if (rc)
rc = ksmbd_vfs_kern_path(work, new_name, LOOKUP_NO_SYMLINKS, &path, 1);
if (rc) {
if (rc != -ENOENT)
goto out;
file_present = false;
else
} else {
path_put(&path);
}
if (ksmbd_share_veto_filename(share, new_name)) {
rc = -ENOENT;
......@@ -5384,11 +5363,14 @@ static int smb2_create_link(struct ksmbd_work *work,
}
ksmbd_debug(SMB, "target name is %s\n", target_name);
rc = ksmbd_vfs_kern_path(link_name, LOOKUP_NO_SYMLINKS, &path, 0);
if (rc)
rc = ksmbd_vfs_kern_path(work, link_name, LOOKUP_NO_SYMLINKS, &path, 0);
if (rc) {
if (rc != -ENOENT)
goto out;
file_present = false;
else
} else {
path_put(&path);
}
if (file_info->ReplaceIfExists) {
if (file_present) {
......@@ -5548,7 +5530,7 @@ static int set_file_allocation_info(struct ksmbd_work *work,
* inode size is retained by backup inode size.
*/
size = i_size_read(inode);
rc = ksmbd_vfs_truncate(work, NULL, fp, alloc_blks * 512);
rc = ksmbd_vfs_truncate(work, fp, alloc_blks * 512);
if (rc) {
pr_err("truncate failed! filename : %s, err %d\n",
fp->filename, rc);
......@@ -5585,7 +5567,7 @@ static int set_end_of_file_info(struct ksmbd_work *work, struct ksmbd_file *fp,
if (inode->i_sb->s_magic != MSDOS_SUPER_MAGIC) {
ksmbd_debug(SMB, "filename : %s truncated to newsize %lld\n",
fp->filename, newsize);
rc = ksmbd_vfs_truncate(work, NULL, fp, newsize);
rc = ksmbd_vfs_truncate(work, fp, newsize);
if (rc) {
ksmbd_debug(SMB, "truncate failed! filename : %s err %d\n",
fp->filename, rc);
......@@ -5862,7 +5844,7 @@ int smb2_set_info(struct ksmbd_work *work)
return 0;
err_out:
if (rc == -EACCES || rc == -EPERM)
if (rc == -EACCES || rc == -EPERM || rc == -EXDEV)
rsp->hdr.Status = STATUS_ACCESS_DENIED;
else if (rc == -EINVAL)
rsp->hdr.Status = STATUS_INVALID_PARAMETER;
......
......@@ -19,6 +19,8 @@
#include <linux/sched/xacct.h>
#include <linux/crc32c.h>
#include "../internal.h" /* for vfs_path_lookup */
#include "glob.h"
#include "oplock.h"
#include "connection.h"
......@@ -44,7 +46,6 @@ static char *extract_last_component(char *path)
p++;
} else {
p = NULL;
pr_err("Invalid path %s\n", path);
}
return p;
}
......@@ -155,7 +156,7 @@ int ksmbd_vfs_query_maximal_access(struct user_namespace *user_ns,
/**
* ksmbd_vfs_create() - vfs helper for smb create file
* @work: work
* @name: file name
* @name: file name that is relative to share
* @mode: file create mode
*
* Return: 0 on success, otherwise error
......@@ -166,7 +167,8 @@ int ksmbd_vfs_create(struct ksmbd_work *work, const char *name, umode_t mode)
struct dentry *dentry;
int err;
dentry = kern_path_create(AT_FDCWD, name, &path, LOOKUP_NO_SYMLINKS);
dentry = ksmbd_vfs_kern_path_create(work, name,
LOOKUP_NO_SYMLINKS, &path);
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
if (err != -ENOENT)
......@@ -191,7 +193,7 @@ int ksmbd_vfs_create(struct ksmbd_work *work, const char *name, umode_t mode)
/**
* ksmbd_vfs_mkdir() - vfs helper for smb create directory
* @work: work
* @name: directory name
* @name: directory name that is relative to share
* @mode: directory create mode
*
* Return: 0 on success, otherwise error
......@@ -203,8 +205,9 @@ int ksmbd_vfs_mkdir(struct ksmbd_work *work, const char *name, umode_t mode)
struct dentry *dentry;
int err;
dentry = kern_path_create(AT_FDCWD, name, &path,
LOOKUP_NO_SYMLINKS | LOOKUP_DIRECTORY);
dentry = ksmbd_vfs_kern_path_create(work, name,
LOOKUP_NO_SYMLINKS | LOOKUP_DIRECTORY,
&path);
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
if (err != -EEXIST)
......@@ -579,7 +582,7 @@ int ksmbd_vfs_fsync(struct ksmbd_work *work, u64 fid, u64 p_id)
/**
* ksmbd_vfs_remove_file() - vfs helper for smb rmdir or unlink
* @name: absolute directory or file name
* @name: directory or file name that is relative to share
*
* Return: 0 on success, otherwise error
*/
......@@ -593,7 +596,7 @@ int ksmbd_vfs_remove_file(struct ksmbd_work *work, char *name)
if (ksmbd_override_fsids(work))
return -ENOMEM;
err = kern_path(name, LOOKUP_NO_SYMLINKS, &path);
err = ksmbd_vfs_kern_path(work, name, LOOKUP_NO_SYMLINKS, &path, false);
if (err) {
ksmbd_debug(VFS, "can't get %s, err %d\n", name, err);
ksmbd_revert_fsids(work);
......@@ -638,7 +641,7 @@ int ksmbd_vfs_remove_file(struct ksmbd_work *work, char *name)
/**
* ksmbd_vfs_link() - vfs helper for creating smb hardlink
* @oldname: source file name
* @newname: hardlink name
* @newname: hardlink name that is relative to share
*
* Return: 0 on success, otherwise error
*/
......@@ -659,8 +662,9 @@ int ksmbd_vfs_link(struct ksmbd_work *work, const char *oldname,
goto out1;
}
dentry = kern_path_create(AT_FDCWD, newname, &newpath,
LOOKUP_NO_SYMLINKS | LOOKUP_REVAL);
dentry = ksmbd_vfs_kern_path_create(work, newname,
LOOKUP_NO_SYMLINKS | LOOKUP_REVAL,
&newpath);
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
pr_err("path create err for %s, err %d\n", newname, err);
......@@ -781,14 +785,17 @@ int ksmbd_vfs_fp_rename(struct ksmbd_work *work, struct ksmbd_file *fp,
int err;
dst_name = extract_last_component(newname);
if (!dst_name)
return -EINVAL;
if (!dst_name) {
dst_name = newname;
newname = "";
}
src_dent_parent = dget_parent(fp->filp->f_path.dentry);
src_dent = fp->filp->f_path.dentry;
err = kern_path(newname, LOOKUP_NO_SYMLINKS | LOOKUP_DIRECTORY,
&dst_path);
err = ksmbd_vfs_kern_path(work, newname,
LOOKUP_NO_SYMLINKS | LOOKUP_DIRECTORY,
&dst_path, false);
if (err) {
ksmbd_debug(VFS, "Cannot get path for %s [%d]\n", newname, err);
goto out;
......@@ -834,31 +841,15 @@ int ksmbd_vfs_fp_rename(struct ksmbd_work *work, struct ksmbd_file *fp,
/**
* ksmbd_vfs_truncate() - vfs helper for smb file truncate
* @work: work
* @name: old filename
* @fid: file id of old file
* @size: truncate to given size
*
* Return: 0 on success, otherwise error
*/
int ksmbd_vfs_truncate(struct ksmbd_work *work, const char *name,
int ksmbd_vfs_truncate(struct ksmbd_work *work,
struct ksmbd_file *fp, loff_t size)
{
struct path path;
int err = 0;
if (name) {
err = kern_path(name, LOOKUP_NO_SYMLINKS, &path);
if (err) {
pr_err("cannot get linux path for %s, err %d\n",
name, err);
return err;
}
err = vfs_truncate(&path, size);
if (err)
pr_err("truncate failed for %s err %d\n",
name, err);
path_put(&path);
} else {
struct file *filp;
filp = fp->filp;
......@@ -887,8 +878,6 @@ int ksmbd_vfs_truncate(struct ksmbd_work *work, const char *name,
if (err)
pr_err("truncate failed for filename : %s err %d\n",
fp->filename, err);
}
return err;
}
......@@ -1206,22 +1195,25 @@ static int ksmbd_vfs_lookup_in_dir(struct path *dir, char *name, size_t namelen)
/**
* ksmbd_vfs_kern_path() - lookup a file and get path info
* @name: name of file for lookup
* @name: file path that is relative to share
* @flags: lookup flags
* @path: if lookup succeed, return path info
* @caseless: caseless filename lookup
*
* Return: 0 on success, otherwise error
*/
int ksmbd_vfs_kern_path(char *name, unsigned int flags, struct path *path,
bool caseless)
int ksmbd_vfs_kern_path(struct ksmbd_work *work, char *name,
unsigned int flags, struct path *path, bool caseless)
{
struct ksmbd_share_config *share_conf = work->tcon->share_conf;
int err;
if (name[0] != '/')
return -EINVAL;
err = kern_path(name, flags, path);
flags |= LOOKUP_BENEATH;
err = vfs_path_lookup(share_conf->vfs_path.dentry,
share_conf->vfs_path.mnt,
name,
flags,
path);
if (!err)
return 0;
......@@ -1235,11 +1227,10 @@ int ksmbd_vfs_kern_path(char *name, unsigned int flags, struct path *path,
return -ENOMEM;
path_len = strlen(filepath);
remain_len = path_len - 1;
remain_len = path_len;
err = kern_path("/", flags, &parent);
if (err)
goto out;
parent = share_conf->vfs_path;
path_get(&parent);
while (d_can_lookup(parent.dentry)) {
char *filename = filepath + path_len - remain_len;
......@@ -1252,21 +1243,21 @@ int ksmbd_vfs_kern_path(char *name, unsigned int flags, struct path *path,
err = ksmbd_vfs_lookup_in_dir(&parent, filename,
filename_len);
if (err) {
path_put(&parent);
if (err)
goto out;
}
path_put(&parent);
next[0] = '\0';
err = kern_path(filepath, flags, &parent);
err = vfs_path_lookup(share_conf->vfs_path.dentry,
share_conf->vfs_path.mnt,
filepath,
flags,
&parent);
if (err)
goto out;
if (is_last) {
path->mnt = parent.mnt;
path->dentry = parent.dentry;
else if (is_last) {
*path = parent;
goto out;
}
......@@ -1282,6 +1273,23 @@ int ksmbd_vfs_kern_path(char *name, unsigned int flags, struct path *path,
return err;
}
struct dentry *ksmbd_vfs_kern_path_create(struct ksmbd_work *work,
const char *name,
unsigned int flags,
struct path *path)
{
char *abs_name;
struct dentry *dent;
abs_name = convert_to_unix_name(work->tcon->share_conf, name);
if (!abs_name)
return ERR_PTR(-ENOMEM);
dent = kern_path_create(AT_FDCWD, abs_name, path, flags);
kfree(abs_name);
return dent;
}
int ksmbd_vfs_remove_acl_xattrs(struct user_namespace *user_ns,
struct dentry *dentry)
{
......
......@@ -126,7 +126,7 @@ int ksmbd_vfs_link(struct ksmbd_work *work,
int ksmbd_vfs_getattr(struct path *path, struct kstat *stat);
int ksmbd_vfs_fp_rename(struct ksmbd_work *work, struct ksmbd_file *fp,
char *newname);
int ksmbd_vfs_truncate(struct ksmbd_work *work, const char *name,
int ksmbd_vfs_truncate(struct ksmbd_work *work,
struct ksmbd_file *fp, loff_t size);
struct srv_copychunk;
int ksmbd_vfs_copy_file_ranges(struct ksmbd_work *work,
......@@ -152,8 +152,13 @@ int ksmbd_vfs_xattr_stream_name(char *stream_name, char **xattr_stream_name,
size_t *xattr_stream_name_size, int s_type);
int ksmbd_vfs_remove_xattr(struct user_namespace *user_ns,
struct dentry *dentry, char *attr_name);
int ksmbd_vfs_kern_path(char *name, unsigned int flags, struct path *path,
int ksmbd_vfs_kern_path(struct ksmbd_work *work,
char *name, unsigned int flags, struct path *path,
bool caseless);
struct dentry *ksmbd_vfs_kern_path_create(struct ksmbd_work *work,
const char *name,
unsigned int flags,
struct path *path);
int ksmbd_vfs_empty_dir(struct ksmbd_file *fp);
void ksmbd_vfs_set_fadvise(struct file *filp, __le32 option);
int ksmbd_vfs_zero_data(struct ksmbd_work *work, struct ksmbd_file *fp,
......
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