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ksmbd: fix racy issue from using ->d_parent and ->d_name

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Al pointed out that ksmbd has racy issue from using ->d_parent and ->d_name
in ksmbd_vfs_unlink and smb2_vfs_rename(). and use new lock_rename_child()
to lock stable parent while underlying rename racy.
Introduce vfs_path_parent_lookup helper to avoid out of share access and
export vfs functions like the following ones to use
vfs_path_parent_lookup().
 - rename __lookup_hash() to lookup_one_qstr_excl().
 - export lookup_one_qstr_excl().
 - export getname_kernel() and putname().

vfs_path_parent_lookup() is used for parent lookup of destination file
using absolute pathname given from FILE_RENAME_INFORMATION request.

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Namjae Jeon 2023-04-21 16:09:01 +09:00 committed by Steve French
parent af36c51e0e
commit 74d7970feb
6 changed files with 294 additions and 397 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

147
fs/ksmbd/smb2pdu.c
View File

@ -2408,7 +2408,7 @@ static int smb2_creat(struct ksmbd_work *work, struct path *path, char *name,
return rc;
}
rc = ksmbd_vfs_kern_path(work, name, 0, path, 0);
rc = ksmbd_vfs_kern_path_locked(work, name, 0, path, 0);
if (rc) {
pr_err("cannot get linux path (%s), err = %d\n",
name, rc);
@ -2699,8 +2699,10 @@ int smb2_open(struct ksmbd_work *work)
goto err_out1;
}
rc = ksmbd_vfs_kern_path(work, name, LOOKUP_NO_SYMLINKS, &path, 1);
rc = ksmbd_vfs_kern_path_locked(work, name, LOOKUP_NO_SYMLINKS, &path, 1);
if (!rc) {
file_present = true;
if (req->CreateOptions & FILE_DELETE_ON_CLOSE_LE) {
/*
* If file exists with under flags, return access
@ -2709,7 +2711,6 @@ int smb2_open(struct ksmbd_work *work)
if (req->CreateDisposition == FILE_OVERWRITE_IF_LE ||
req->CreateDisposition == FILE_OPEN_IF_LE) {
rc = -EACCES;
path_put(&path);
goto err_out;
}
@ -2717,26 +2718,23 @@ int smb2_open(struct ksmbd_work *work)
ksmbd_debug(SMB,
"User does not have write permission\n");
rc = -EACCES;
path_put(&path);
goto err_out;
}
} else if (d_is_symlink(path.dentry)) {
rc = -EACCES;
path_put(&path);
goto err_out;
}
}
if (rc) {
file_present = true;
idmap = mnt_idmap(path.mnt);
} else {
if (rc != -ENOENT)
goto err_out;
ksmbd_debug(SMB, "can not get linux path for %s, rc = %d\n",
name, rc);
rc = 0;
} else {
file_present = true;
idmap = mnt_idmap(path.mnt);
}
if (stream_name) {
if (req->CreateOptions & FILE_DIRECTORY_FILE_LE) {
if (s_type == DATA_STREAM) {
@ -2864,8 +2862,9 @@ int smb2_open(struct ksmbd_work *work)
if ((daccess & FILE_DELETE_LE) ||
(req->CreateOptions & FILE_DELETE_ON_CLOSE_LE)) {
rc = ksmbd_vfs_may_delete(idmap,
path.dentry);
rc = inode_permission(idmap,
d_inode(path.dentry->d_parent),
MAY_EXEC | MAY_WRITE);
if (rc)
goto err_out;
}
@ -3236,10 +3235,13 @@ int smb2_open(struct ksmbd_work *work)
}
err_out:
if (file_present || created)
path_put(&path);
if (file_present || created) {
inode_unlock(d_inode(path.dentry->d_parent));
dput(path.dentry);
}
ksmbd_revert_fsids(work);
err_out1:
if (rc) {
if (rc == -EINVAL)
rsp->hdr.Status = STATUS_INVALID_PARAMETER;
@ -5390,44 +5392,19 @@ int smb2_echo(struct ksmbd_work *work)
static int smb2_rename(struct ksmbd_work *work,
struct ksmbd_file *fp,
struct mnt_idmap *idmap,
struct smb2_file_rename_info *file_info,
struct nls_table *local_nls)
{
struct ksmbd_share_config *share = fp->tcon->share_conf;
char *new_name = NULL, *abs_oldname = NULL, *old_name = NULL;
char *pathname = NULL;
struct path path;
bool file_present = true;
int rc;
char *new_name = NULL;
int rc, flags = 0;
ksmbd_debug(SMB, "setting FILE_RENAME_INFO\n");
pathname = kmalloc(PATH_MAX, GFP_KERNEL);
if (!pathname)
return -ENOMEM;
abs_oldname = file_path(fp->filp, pathname, PATH_MAX);
if (IS_ERR(abs_oldname)) {
rc = -EINVAL;
goto out;
}
old_name = strrchr(abs_oldname, '/');
if (old_name && old_name[1] != '\0') {
old_name++;
} else {
ksmbd_debug(SMB, "can't get last component in path %s\n",
abs_oldname);
rc = -ENOENT;
goto out;
}
new_name = smb2_get_name(file_info->FileName,
le32_to_cpu(file_info->FileNameLength),
local_nls);
if (IS_ERR(new_name)) {
rc = PTR_ERR(new_name);
goto out;
}
if (IS_ERR(new_name))
return PTR_ERR(new_name);
if (strchr(new_name, ':')) {
int s_type;
@ -5453,7 +5430,7 @@ static int smb2_rename(struct ksmbd_work *work,
if (rc)
goto out;
rc = ksmbd_vfs_setxattr(idmap,
rc = ksmbd_vfs_setxattr(file_mnt_idmap(fp->filp),
fp->filp->f_path.dentry,
xattr_stream_name,
NULL, 0, 0);
@ -5468,47 +5445,18 @@ static int smb2_rename(struct ksmbd_work *work,
}
ksmbd_debug(SMB, "new name %s\n", new_name);
rc = ksmbd_vfs_kern_path(work, new_name, LOOKUP_NO_SYMLINKS, &path, 1);
if (rc) {
if (rc != -ENOENT)
goto out;
file_present = false;
} else {
path_put(&path);
}
if (ksmbd_share_veto_filename(share, new_name)) {
rc = -ENOENT;
ksmbd_debug(SMB, "Can't rename vetoed file: %s\n", new_name);
goto out;
}
if (file_info->ReplaceIfExists) {
if (file_present) {
rc = ksmbd_vfs_remove_file(work, new_name);
if (rc) {
if (rc != -ENOTEMPTY)
rc = -EINVAL;
ksmbd_debug(SMB, "cannot delete %s, rc %d\n",
new_name, rc);
goto out;
}
}
} else {
if (file_present &&
strncmp(old_name, path.dentry->d_name.name, strlen(old_name))) {
rc = -EEXIST;
ksmbd_debug(SMB,
"cannot rename already existing file\n");
goto out;
}
}
if (!file_info->ReplaceIfExists)
flags = RENAME_NOREPLACE;
rc = ksmbd_vfs_fp_rename(work, fp, new_name);
rc = ksmbd_vfs_rename(work, &fp->filp->f_path, new_name, flags);
out:
kfree(pathname);
if (!IS_ERR(new_name))
kfree(new_name);
kfree(new_name);
return rc;
}
@ -5548,18 +5496,17 @@ static int smb2_create_link(struct ksmbd_work *work,
}
ksmbd_debug(SMB, "target name is %s\n", target_name);
rc = ksmbd_vfs_kern_path(work, link_name, LOOKUP_NO_SYMLINKS, &path, 0);
rc = ksmbd_vfs_kern_path_locked(work, link_name, LOOKUP_NO_SYMLINKS,
&path, 0);
if (rc) {
if (rc != -ENOENT)
goto out;
file_present = false;
} else {
path_put(&path);
}
if (file_info->ReplaceIfExists) {
if (file_present) {
rc = ksmbd_vfs_remove_file(work, link_name);
rc = ksmbd_vfs_remove_file(work, &path);
if (rc) {
rc = -EINVAL;
ksmbd_debug(SMB, "cannot delete %s\n",
@ -5579,6 +5526,10 @@ static int smb2_create_link(struct ksmbd_work *work,
if (rc)
rc = -EINVAL;
out:
if (file_present) {
inode_unlock(d_inode(path.dentry->d_parent));
path_put(&path);
}
if (!IS_ERR(link_name))
kfree(link_name);
kfree(pathname);
@ -5756,12 +5707,6 @@ static int set_rename_info(struct ksmbd_work *work, struct ksmbd_file *fp,
struct smb2_file_rename_info *rename_info,
unsigned int buf_len)
{
struct mnt_idmap *idmap;
struct ksmbd_file *parent_fp;
struct dentry *parent;
struct dentry *dentry = fp->filp->f_path.dentry;
int ret;
if (!(fp->daccess & FILE_DELETE_LE)) {
pr_err("no right to delete : 0x%x\n", fp->daccess);
return -EACCES;
@ -5771,32 +5716,10 @@ static int set_rename_info(struct ksmbd_work *work, struct ksmbd_file *fp,
le32_to_cpu(rename_info->FileNameLength))
return -EINVAL;
idmap = file_mnt_idmap(fp->filp);
if (ksmbd_stream_fd(fp))
goto next;
if (!le32_to_cpu(rename_info->FileNameLength))
return -EINVAL;
parent = dget_parent(dentry);
ret = ksmbd_vfs_lock_parent(idmap, parent, dentry);
if (ret) {
dput(parent);
return ret;
}
parent_fp = ksmbd_lookup_fd_inode(d_inode(parent));
inode_unlock(d_inode(parent));
dput(parent);
if (parent_fp) {
if (parent_fp->daccess & FILE_DELETE_LE) {
pr_err("parent dir is opened with delete access\n");
ksmbd_fd_put(work, parent_fp);
return -ESHARE;
}
ksmbd_fd_put(work, parent_fp);
}
next:
return smb2_rename(work, fp, idmap, rename_info,
work->conn->local_nls);
return smb2_rename(work, fp, rename_info, work->conn->local_nls);
}
static int set_file_disposition_info(struct ksmbd_file *fp,

457
fs/ksmbd/vfs.c
View File

@ -18,6 +18,7 @@
#include <linux/vmalloc.h>
#include <linux/sched/xacct.h>
#include <linux/crc32c.h>
#include <linux/namei.h>
#include "glob.h"
#include "oplock.h"
@ -35,19 +36,6 @@
#include "mgmt/user_session.h"
#include "mgmt/user_config.h"
static char *extract_last_component(char *path)
{
char *p = strrchr(path, '/');
if (p && p[1] != '\0') {
*p = '\0';
p++;
} else {
p = NULL;
}
return p;
}
static void ksmbd_vfs_inherit_owner(struct ksmbd_work *work,
struct inode *parent_inode,
struct inode *inode)
@ -61,65 +49,77 @@ static void ksmbd_vfs_inherit_owner(struct ksmbd_work *work,
/**
* ksmbd_vfs_lock_parent() - lock parent dentry if it is stable
*
* the parent dentry got by dget_parent or @parent could be
* unstable, we try to lock a parent inode and lookup the
* child dentry again.
*
* the reference count of @parent isn't incremented.
*/
int ksmbd_vfs_lock_parent(struct mnt_idmap *idmap, struct dentry *parent,
struct dentry *child)
int ksmbd_vfs_lock_parent(struct dentry *parent, struct dentry *child)
{
struct dentry *dentry;
int ret = 0;
inode_lock_nested(d_inode(parent), I_MUTEX_PARENT);
dentry = lookup_one(idmap, child->d_name.name, parent,
child->d_name.len);
if (IS_ERR(dentry)) {
ret = PTR_ERR(dentry);
goto out_err;
if (child->d_parent != parent) {
inode_unlock(d_inode(parent));
return -ENOENT;
}
if (dentry != child) {
ret = -ESTALE;
dput(dentry);
goto out_err;
}
dput(dentry);
return 0;
out_err:
inode_unlock(d_inode(parent));
return ret;
}
int ksmbd_vfs_may_delete(struct mnt_idmap *idmap,
struct dentry *dentry)
static int ksmbd_vfs_path_lookup_locked(struct ksmbd_share_config *share_conf,
char *pathname, unsigned int flags,
struct path *path)
{
struct dentry *parent;
int ret;
struct qstr last;
struct filename *filename;
struct path *root_share_path = &share_conf->vfs_path;
int err, type;
struct path parent_path;
struct dentry *d;
parent = dget_parent(dentry);
ret = ksmbd_vfs_lock_parent(idmap, parent, dentry);
if (ret) {
dput(parent);
return ret;
if (pathname[0] == '\0') {
pathname = share_conf->path;
root_share_path = NULL;
} else {
flags |= LOOKUP_BENEATH;
}
ret = inode_permission(idmap, d_inode(parent),
MAY_EXEC | MAY_WRITE);
filename = getname_kernel(pathname);
if (IS_ERR(filename))
return PTR_ERR(filename);
inode_unlock(d_inode(parent));
dput(parent);
return ret;
err = vfs_path_parent_lookup(filename, flags,
&parent_path, &last, &type,
root_share_path);
putname(filename);
if (err)
return err;
if (unlikely(type != LAST_NORM)) {
path_put(&parent_path);
return -ENOENT;
}
inode_lock_nested(parent_path.dentry->d_inode, I_MUTEX_PARENT);
d = lookup_one_qstr_excl(&last, parent_path.dentry, 0);
if (IS_ERR(d))
goto err_out;
if (d_is_negative(d)) {
dput(d);
goto err_out;
}
path->dentry = d;
path->mnt = share_conf->vfs_path.mnt;
path_put(&parent_path);
return 0;
err_out:
inode_unlock(parent_path.dentry->d_inode);
path_put(&parent_path);
return -ENOENT;
}
int ksmbd_vfs_query_maximal_access(struct mnt_idmap *idmap,
struct dentry *dentry, __le32 *daccess)
{
struct dentry *parent;
int ret = 0;
*daccess = cpu_to_le32(FILE_READ_ATTRIBUTES | READ_CONTROL);
@ -136,18 +136,9 @@ int ksmbd_vfs_query_maximal_access(struct mnt_idmap *idmap,
if (!inode_permission(idmap, d_inode(dentry), MAY_OPEN | MAY_EXEC))
*daccess |= FILE_EXECUTE_LE;
parent = dget_parent(dentry);
ret = ksmbd_vfs_lock_parent(idmap, parent, dentry);
if (ret) {
dput(parent);
return ret;
}
if (!inode_permission(idmap, d_inode(parent), MAY_EXEC | MAY_WRITE))
if (!inode_permission(idmap, d_inode(dentry->d_parent), MAY_EXEC | MAY_WRITE))
*daccess |= FILE_DELETE_LE;
inode_unlock(d_inode(parent));
dput(parent);
return ret;
}
@ -580,54 +571,32 @@ int ksmbd_vfs_fsync(struct ksmbd_work *work, u64 fid, u64 p_id)
*
* Return: 0 on success, otherwise error
*/
int ksmbd_vfs_remove_file(struct ksmbd_work *work, char *name)
int ksmbd_vfs_remove_file(struct ksmbd_work *work, const struct path *path)
{
struct mnt_idmap *idmap;
struct path path;
struct dentry *parent;
struct dentry *parent = path->dentry->d_parent;
int err;
if (ksmbd_override_fsids(work))
return -ENOMEM;
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);
return err;
}
idmap = mnt_idmap(path.mnt);
parent = dget_parent(path.dentry);
err = ksmbd_vfs_lock_parent(idmap, parent, path.dentry);
if (err) {
dput(parent);
path_put(&path);
ksmbd_revert_fsids(work);
return err;
}
if (!d_inode(path.dentry)->i_nlink) {
if (!d_inode(path->dentry)->i_nlink) {
err = -ENOENT;
goto out_err;
}
if (S_ISDIR(d_inode(path.dentry)->i_mode)) {
err = vfs_rmdir(idmap, d_inode(parent), path.dentry);
idmap = mnt_idmap(path->mnt);
if (S_ISDIR(d_inode(path->dentry)->i_mode)) {
err = vfs_rmdir(idmap, d_inode(parent), path->dentry);
if (err && err != -ENOTEMPTY)
ksmbd_debug(VFS, "%s: rmdir failed, err %d\n", name,
err);
ksmbd_debug(VFS, "rmdir failed, err %d\n", err);
} else {
err = vfs_unlink(idmap, d_inode(parent), path.dentry, NULL);
err = vfs_unlink(idmap, d_inode(parent), path->dentry, NULL);
if (err)
ksmbd_debug(VFS, "%s: unlink failed, err %d\n", name,
err);
ksmbd_debug(VFS, "unlink failed, err %d\n", err);
}
out_err:
inode_unlock(d_inode(parent));
dput(parent);
path_put(&path);
ksmbd_revert_fsids(work);
return err;
}
@ -686,152 +655,117 @@ out1:
return err;
}
static int ksmbd_validate_entry_in_use(struct dentry *src_dent)
int ksmbd_vfs_rename(struct ksmbd_work *work, const struct path *old_path,
char *newname, int flags)
{
struct dentry *dst_dent;
spin_lock(&src_dent->d_lock);
list_for_each_entry(dst_dent, &src_dent->d_subdirs, d_child) {
struct ksmbd_file *child_fp;
if (d_really_is_negative(dst_dent))
continue;
child_fp = ksmbd_lookup_fd_inode(d_inode(dst_dent));
if (child_fp) {
spin_unlock(&src_dent->d_lock);
ksmbd_debug(VFS, "Forbid rename, sub file/dir is in use\n");
return -EACCES;
}
}
spin_unlock(&src_dent->d_lock);
return 0;
}
static int __ksmbd_vfs_rename(struct ksmbd_work *work,
struct mnt_idmap *src_idmap,
struct dentry *src_dent_parent,
struct dentry *src_dent,
struct mnt_idmap *dst_idmap,
struct dentry *dst_dent_parent,
struct dentry *trap_dent,
char *dst_name)
{
struct dentry *dst_dent;
int err;
if (!work->tcon->posix_extensions) {
err = ksmbd_validate_entry_in_use(src_dent);
if (err)
return err;
}
if (d_really_is_negative(src_dent_parent))
return -ENOENT;
if (d_really_is_negative(dst_dent_parent))
return -ENOENT;
if (d_really_is_negative(src_dent))
return -ENOENT;
if (src_dent == trap_dent)
return -EINVAL;
struct dentry *old_parent, *new_dentry, *trap;
struct dentry *old_child = old_path->dentry;
struct path new_path;
struct qstr new_last;
struct renamedata rd;
struct filename *to;
struct ksmbd_share_config *share_conf = work->tcon->share_conf;
struct ksmbd_file *parent_fp;
int new_type;
int err, lookup_flags = LOOKUP_NO_SYMLINKS;
if (ksmbd_override_fsids(work))
return -ENOMEM;
dst_dent = lookup_one(dst_idmap, dst_name,
dst_dent_parent, strlen(dst_name));
err = PTR_ERR(dst_dent);
if (IS_ERR(dst_dent)) {
pr_err("lookup failed %s [%d]\n", dst_name, err);
goto out;
to = getname_kernel(newname);
if (IS_ERR(to)) {
err = PTR_ERR(to);
goto revert_fsids;
}
err = -ENOTEMPTY;
if (dst_dent != trap_dent && !d_really_is_positive(dst_dent)) {
struct renamedata rd = {
.old_mnt_idmap = src_idmap,
.old_dir = d_inode(src_dent_parent),
.old_dentry = src_dent,
.new_mnt_idmap = dst_idmap,
.new_dir = d_inode(dst_dent_parent),
.new_dentry = dst_dent,
};
err = vfs_rename(&rd);
}
retry:
err = vfs_path_parent_lookup(to, lookup_flags | LOOKUP_BENEATH,
&new_path, &new_last, &new_type,
&share_conf->vfs_path);
if (err)
pr_err("vfs_rename failed err %d\n", err);
if (dst_dent)
dput(dst_dent);
out:
goto out1;
if (old_path->mnt != new_path.mnt) {
err = -EXDEV;
goto out2;
}
trap = lock_rename_child(old_child, new_path.dentry);
old_parent = dget(old_child->d_parent);
if (d_unhashed(old_child)) {
err = -EINVAL;
goto out3;
}
parent_fp = ksmbd_lookup_fd_inode(d_inode(old_child->d_parent));
if (parent_fp) {
if (parent_fp->daccess & FILE_DELETE_LE) {
pr_err("parent dir is opened with delete access\n");
err = -ESHARE;
ksmbd_fd_put(work, parent_fp);
goto out3;
}
ksmbd_fd_put(work, parent_fp);
}
new_dentry = lookup_one_qstr_excl(&new_last, new_path.dentry,
lookup_flags | LOOKUP_RENAME_TARGET);
if (IS_ERR(new_dentry)) {
err = PTR_ERR(new_dentry);
goto out3;
}
if (d_is_symlink(new_dentry)) {
err = -EACCES;
goto out4;
}
if ((flags & RENAME_NOREPLACE) && d_is_positive(new_dentry)) {
err = -EEXIST;
goto out4;
}
if (old_child == trap) {
err = -EINVAL;
goto out4;
}
if (new_dentry == trap) {
err = -ENOTEMPTY;
goto out4;
}
rd.old_mnt_idmap = mnt_idmap(old_path->mnt),
rd.old_dir = d_inode(old_parent),
rd.old_dentry = old_child,
rd.new_mnt_idmap = mnt_idmap(new_path.mnt),
rd.new_dir = new_path.dentry->d_inode,
rd.new_dentry = new_dentry,
rd.flags = flags,
err = vfs_rename(&rd);
if (err)
ksmbd_debug(VFS, "vfs_rename failed err %d\n", err);
out4:
dput(new_dentry);
out3:
dput(old_parent);
unlock_rename(old_parent, new_path.dentry);
out2:
path_put(&new_path);
if (retry_estale(err, lookup_flags)) {
lookup_flags |= LOOKUP_REVAL;
goto retry;
}
out1:
putname(to);
revert_fsids:
ksmbd_revert_fsids(work);
return err;
}
int ksmbd_vfs_fp_rename(struct ksmbd_work *work, struct ksmbd_file *fp,
char *newname)
{
struct mnt_idmap *idmap;
struct path dst_path;
struct dentry *src_dent_parent, *dst_dent_parent;
struct dentry *src_dent, *trap_dent, *src_child;
char *dst_name;
int err;
dst_name = extract_last_component(newname);
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 = 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;
}
dst_dent_parent = dst_path.dentry;
trap_dent = lock_rename(src_dent_parent, dst_dent_parent);
dget(src_dent);
dget(dst_dent_parent);
idmap = file_mnt_idmap(fp->filp);
src_child = lookup_one(idmap, src_dent->d_name.name, src_dent_parent,
src_dent->d_name.len);
if (IS_ERR(src_child)) {
err = PTR_ERR(src_child);
goto out_lock;
}
if (src_child != src_dent) {
err = -ESTALE;
dput(src_child);
goto out_lock;
}
dput(src_child);
err = __ksmbd_vfs_rename(work,
idmap,
src_dent_parent,
src_dent,
mnt_idmap(dst_path.mnt),
dst_dent_parent,
trap_dent,
dst_name);
out_lock:
dput(src_dent);
dput(dst_dent_parent);
unlock_rename(src_dent_parent, dst_dent_parent);
path_put(&dst_path);
out:
dput(src_dent_parent);
return err;
}
/**
* ksmbd_vfs_truncate() - vfs helper for smb file truncate
* @work: work
@ -1079,14 +1013,16 @@ int ksmbd_vfs_remove_xattr(struct mnt_idmap *idmap,
return vfs_removexattr(idmap, dentry, attr_name);
}
int ksmbd_vfs_unlink(struct mnt_idmap *idmap,
struct dentry *dir, struct dentry *dentry)
int ksmbd_vfs_unlink(struct file *filp)
{
int err = 0;
struct dentry *dir, *dentry = filp->f_path.dentry;
struct mnt_idmap *idmap = file_mnt_idmap(filp);
err = ksmbd_vfs_lock_parent(idmap, dir, dentry);
dir = dget_parent(dentry);
err = ksmbd_vfs_lock_parent(dir, dentry);
if (err)
return err;
goto out;
dget(dentry);
if (S_ISDIR(d_inode(dentry)->i_mode))
@ -1098,6 +1034,8 @@ int ksmbd_vfs_unlink(struct mnt_idmap *idmap,
inode_unlock(d_inode(dir));
if (err)
ksmbd_debug(VFS, "failed to delete, err %d\n", err);
out:
dput(dir);
return err;
}
@ -1200,7 +1138,7 @@ static int ksmbd_vfs_lookup_in_dir(const struct path *dir, char *name,
}
/**
* ksmbd_vfs_kern_path() - lookup a file and get path info
* ksmbd_vfs_kern_path_locked() - lookup a file and get path info
* @name: file path that is relative to share
* @flags: lookup flags
* @path: if lookup succeed, return path info
@ -1208,24 +1146,20 @@ static int ksmbd_vfs_lookup_in_dir(const struct path *dir, char *name,
*
* Return: 0 on success, otherwise error
*/
int ksmbd_vfs_kern_path(struct ksmbd_work *work, char *name,
unsigned int flags, struct path *path, bool caseless)
int ksmbd_vfs_kern_path_locked(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;
struct path parent_path;
flags |= LOOKUP_BENEATH;
err = vfs_path_lookup(share_conf->vfs_path.dentry,
share_conf->vfs_path.mnt,
name,
flags,
path);
err = ksmbd_vfs_path_lookup_locked(share_conf, name, flags, path);
if (!err)
return 0;
return err;
if (caseless) {
char *filepath;
struct path parent;
size_t path_len, remain_len;
filepath = kstrdup(name, GFP_KERNEL);
@ -1235,10 +1169,10 @@ int ksmbd_vfs_kern_path(struct ksmbd_work *work, char *name,
path_len = strlen(filepath);
remain_len = path_len;
parent = share_conf->vfs_path;
path_get(&parent);
parent_path = share_conf->vfs_path;
path_get(&parent_path);
while (d_can_lookup(parent.dentry)) {
while (d_can_lookup(parent_path.dentry)) {
char *filename = filepath + path_len - remain_len;
char *next = strchrnul(filename, '/');
size_t filename_len = next - filename;
@ -1247,12 +1181,11 @@ int ksmbd_vfs_kern_path(struct ksmbd_work *work, char *name,
if (filename_len == 0)
break;
err = ksmbd_vfs_lookup_in_dir(&parent, filename,
err = ksmbd_vfs_lookup_in_dir(&parent_path, filename,
filename_len,
work->conn->um);
path_put(&parent);
if (err)
goto out;
goto out2;
next[0] = '\0';
@ -1260,23 +1193,31 @@ int ksmbd_vfs_kern_path(struct ksmbd_work *work, char *name,
share_conf->vfs_path.mnt,
filepath,
flags,
&parent);
path);
if (err)
goto out;
else if (is_last) {
*path = parent;
goto out;
}
goto out2;
else if (is_last)
goto out1;
path_put(&parent_path);
parent_path = *path;
next[0] = '/';
remain_len -= filename_len + 1;
}
path_put(&parent);
err = -EINVAL;
out:
out2:
path_put(&parent_path);
out1:
kfree(filepath);
}
if (!err) {
err = ksmbd_vfs_lock_parent(parent_path.dentry, path->dentry);
if (err)
dput(path->dentry);
path_put(&parent_path);
}
return err;
}

19
fs/ksmbd/vfs.h
View File

@ -71,9 +71,7 @@ struct ksmbd_kstat {
__le32 file_attributes;
};
int ksmbd_vfs_lock_parent(struct mnt_idmap *idmap, struct dentry *parent,
struct dentry *child);
int ksmbd_vfs_may_delete(struct mnt_idmap *idmap, struct dentry *dentry);
int ksmbd_vfs_lock_parent(struct dentry *parent, struct dentry *child);
int ksmbd_vfs_query_maximal_access(struct mnt_idmap *idmap,
struct dentry *dentry, __le32 *daccess);
int ksmbd_vfs_create(struct ksmbd_work *work, const char *name, umode_t mode);
@ -84,12 +82,12 @@ int ksmbd_vfs_write(struct ksmbd_work *work, struct ksmbd_file *fp,
char *buf, size_t count, loff_t *pos, bool sync,
ssize_t *written);
int ksmbd_vfs_fsync(struct ksmbd_work *work, u64 fid, u64 p_id);
int ksmbd_vfs_remove_file(struct ksmbd_work *work, char *name);
int ksmbd_vfs_remove_file(struct ksmbd_work *work, const struct path *path);
int ksmbd_vfs_link(struct ksmbd_work *work,
const char *oldname, const char *newname);
int ksmbd_vfs_getattr(const struct path *path, struct kstat *stat);
int ksmbd_vfs_fp_rename(struct ksmbd_work *work, struct ksmbd_file *fp,
char *newname);
int ksmbd_vfs_rename(struct ksmbd_work *work, const struct path *old_path,
char *newname, int flags);
int ksmbd_vfs_truncate(struct ksmbd_work *work,
struct ksmbd_file *fp, loff_t size);
struct srv_copychunk;
@ -116,9 +114,9 @@ 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 mnt_idmap *idmap,
struct dentry *dentry, char *attr_name);
int ksmbd_vfs_kern_path(struct ksmbd_work *work,
char *name, unsigned int flags, struct path *path,
bool caseless);
int ksmbd_vfs_kern_path_locked(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,
@ -131,8 +129,7 @@ struct file_allocated_range_buffer;
int ksmbd_vfs_fqar_lseek(struct ksmbd_file *fp, loff_t start, loff_t length,
struct file_allocated_range_buffer *ranges,
unsigned int in_count, unsigned int *out_count);
int ksmbd_vfs_unlink(struct mnt_idmap *idmap, struct dentry *dir,
struct dentry *dentry);
int ksmbd_vfs_unlink(struct file *filp);
void *ksmbd_vfs_init_kstat(char **p, struct ksmbd_kstat *ksmbd_kstat);
int ksmbd_vfs_fill_dentry_attrs(struct ksmbd_work *work,
struct mnt_idmap *idmap,

5
fs/ksmbd/vfs_cache.c
View File

@ -244,7 +244,6 @@ void ksmbd_release_inode_hash(void)
static void __ksmbd_inode_close(struct ksmbd_file *fp)
{
struct dentry *dir, *dentry;
struct ksmbd_inode *ci = fp->f_ci;
int err;
struct file *filp;
@ -263,11 +262,9 @@ static void __ksmbd_inode_close(struct ksmbd_file *fp)
if (atomic_dec_and_test(&ci->m_count)) {
write_lock(&ci->m_lock);
if (ci->m_flags & (S_DEL_ON_CLS | S_DEL_PENDING)) {
dentry = filp->f_path.dentry;
dir = dentry->d_parent;
ci->m_flags &= ~(S_DEL_ON_CLS | S_DEL_PENDING);
write_unlock(&ci->m_lock);
ksmbd_vfs_unlink(file_mnt_idmap(filp), dir, dentry);
ksmbd_vfs_unlink(filp);
write_lock(&ci->m_lock);
}
write_unlock(&ci->m_lock);

57
fs/namei.c
View File

@ -254,6 +254,7 @@ getname_kernel(const char * filename)
return result;
}
EXPORT_SYMBOL(getname_kernel);
void putname(struct filename *name)
{
@ -271,6 +272,7 @@ void putname(struct filename *name)
} else
__putname(name);
}
EXPORT_SYMBOL(putname);
/**
* check_acl - perform ACL permission checking
@ -1581,8 +1583,9 @@ static struct dentry *lookup_dcache(const struct qstr *name,
* when directory is guaranteed to have no in-lookup children
* at all.
*/
static struct dentry *__lookup_hash(const struct qstr *name,
struct dentry *base, unsigned int flags)
struct dentry *lookup_one_qstr_excl(const struct qstr *name,
struct dentry *base,
unsigned int flags)
{
struct dentry *dentry = lookup_dcache(name, base, flags);
struct dentry *old;
@ -1606,6 +1609,7 @@ static struct dentry *__lookup_hash(const struct qstr *name,
}
return dentry;
}
EXPORT_SYMBOL(lookup_one_qstr_excl);
static struct dentry *lookup_fast(struct nameidata *nd)
{
@ -2532,16 +2536,17 @@ static int path_parentat(struct nameidata *nd, unsigned flags,
}
/* Note: this does not consume "name" */
static int filename_parentat(int dfd, struct filename *name,
unsigned int flags, struct path *parent,
struct qstr *last, int *type)
static int __filename_parentat(int dfd, struct filename *name,
unsigned int flags, struct path *parent,
struct qstr *last, int *type,
const struct path *root)
{
int retval;
struct nameidata nd;
if (IS_ERR(name))
return PTR_ERR(name);
set_nameidata(&nd, dfd, name, NULL);
set_nameidata(&nd, dfd, name, root);
retval = path_parentat(&nd, flags | LOOKUP_RCU, parent);
if (unlikely(retval == -ECHILD))
retval = path_parentat(&nd, flags, parent);
@ -2556,6 +2561,13 @@ static int filename_parentat(int dfd, struct filename *name,
return retval;
}
static int filename_parentat(int dfd, struct filename *name,
unsigned int flags, struct path *parent,
struct qstr *last, int *type)
{
return __filename_parentat(dfd, name, flags, parent, last, type, NULL);
}
/* does lookup, returns the object with parent locked */
static struct dentry *__kern_path_locked(struct filename *name, struct path *path)
{
@ -2571,7 +2583,7 @@ static struct dentry *__kern_path_locked(struct filename *name, struct path *pat
return ERR_PTR(-EINVAL);
}
inode_lock_nested(path->dentry->d_inode, I_MUTEX_PARENT);
d = __lookup_hash(&last, path->dentry, 0);
d = lookup_one_qstr_excl(&last, path->dentry, 0);
if (IS_ERR(d)) {
inode_unlock(path->dentry->d_inode);
path_put(path);
@ -2599,6 +2611,24 @@ int kern_path(const char *name, unsigned int flags, struct path *path)
}
EXPORT_SYMBOL(kern_path);
/**
* vfs_path_parent_lookup - lookup a parent path relative to a dentry-vfsmount pair
* @filename: filename structure
* @flags: lookup flags
* @parent: pointer to struct path to fill
* @last: last component
* @type: type of the last component
* @root: pointer to struct path of the base directory
*/
int vfs_path_parent_lookup(struct filename *filename, unsigned int flags,
struct path *parent, struct qstr *last, int *type,
const struct path *root)
{
return __filename_parentat(AT_FDCWD, filename, flags, parent, last,
type, root);
}
EXPORT_SYMBOL(vfs_path_parent_lookup);
/**
* vfs_path_lookup - lookup a file path relative to a dentry-vfsmount pair
* @dentry: pointer to dentry of the base directory
@ -3852,7 +3882,8 @@ static struct dentry *filename_create(int dfd, struct filename *name,
if (last.name[last.len] && !want_dir)
create_flags = 0;
inode_lock_nested(path->dentry->d_inode, I_MUTEX_PARENT);
dentry = __lookup_hash(&last, path->dentry, reval_flag | create_flags);
dentry = lookup_one_qstr_excl(&last, path->dentry,
reval_flag | create_flags);
if (IS_ERR(dentry))
goto unlock;
@ -4212,7 +4243,7 @@ retry:
goto exit2;
inode_lock_nested(path.dentry->d_inode, I_MUTEX_PARENT);
dentry = __lookup_hash(&last, path.dentry, lookup_flags);
dentry = lookup_one_qstr_excl(&last, path.dentry, lookup_flags);
error = PTR_ERR(dentry);
if (IS_ERR(dentry))
goto exit3;
@ -4345,7 +4376,7 @@ retry:
goto exit2;
retry_deleg:
inode_lock_nested(path.dentry->d_inode, I_MUTEX_PARENT);
dentry = __lookup_hash(&last, path.dentry, lookup_flags);
dentry = lookup_one_qstr_excl(&last, path.dentry, lookup_flags);
error = PTR_ERR(dentry);
if (!IS_ERR(dentry)) {
@ -4909,7 +4940,8 @@ retry:
retry_deleg:
trap = lock_rename(new_path.dentry, old_path.dentry);
old_dentry = __lookup_hash(&old_last, old_path.dentry, lookup_flags);
old_dentry = lookup_one_qstr_excl(&old_last, old_path.dentry,
lookup_flags);
error = PTR_ERR(old_dentry);
if (IS_ERR(old_dentry))
goto exit3;
@ -4917,7 +4949,8 @@ retry_deleg:
error = -ENOENT;
if (d_is_negative(old_dentry))
goto exit4;
new_dentry = __lookup_hash(&new_last, new_path.dentry, lookup_flags | target_flags);
new_dentry = lookup_one_qstr_excl(&new_last, new_path.dentry,
lookup_flags | target_flags);
error = PTR_ERR(new_dentry);
if (IS_ERR(new_dentry))
goto exit4;

6
include/linux/namei.h
View File

@ -57,12 +57,18 @@ static inline int user_path_at(int dfd, const char __user *name, unsigned flags,
return user_path_at_empty(dfd, name, flags, path, NULL);
}
struct dentry *lookup_one_qstr_excl(const struct qstr *name,
struct dentry *base,
unsigned int flags);
extern int kern_path(const char *, unsigned, struct path *);
extern struct dentry *kern_path_create(int, const char *, struct path *, unsigned int);
extern struct dentry *user_path_create(int, const char __user *, struct path *, unsigned int);
extern void done_path_create(struct path *, struct dentry *);
extern struct dentry *kern_path_locked(const char *, struct path *);
int vfs_path_parent_lookup(struct filename *filename, unsigned int flags,
struct path *parent, struct qstr *last, int *type,
const struct path *root);
int vfs_path_lookup(struct dentry *, struct vfsmount *, const char *,
unsigned int, struct path *);