* [PATCH v8 3/3] ksmbd: fix racy issue from using ->d_parent and ->d_name
2023-03-15 22:34 [PATCH v8 0/3] ksmbd patches included vfs changes Namjae Jeon
2023-03-15 22:34 ` [PATCH v8 1/3] ksmbd: remove internal.h include Namjae Jeon
2023-03-15 22:34 ` [PATCH v8 2/3] fs: introduce lock_rename_child() helper Namjae Jeon
@ 2023-03-15 22:34 ` Namjae Jeon
2023-04-21 2:35 ` [PATCH v8 0/3] ksmbd patches included vfs changes Al Viro
2023-06-13 10:57 ` Amir Goldstein
4 siblings, 0 replies; 10+ messages in thread
From: Namjae Jeon @ 2023-03-15 22:34 UTC (permalink / raw)
To: viro
Cc: linux-fsdevel, linux-cifs, smfrench, senozhatsky, tom, brauner,
Namjae Jeon
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>
---
fs/ksmbd/smb2pdu.c | 147 ++++----------
fs/ksmbd/vfs.c | 433 ++++++++++++++++++------------------------
fs/ksmbd/vfs.h | 19 +-
fs/ksmbd/vfs_cache.c | 5 +-
fs/namei.c | 57 ++++--
include/linux/namei.h | 6 +
6 files changed, 282 insertions(+), 385 deletions(-)
diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index 547a10977454..e27f86b03ad4 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -2424,7 +2424,7 @@ 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);
@@ -2715,8 +2715,10 @@ 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
@@ -2725,7 +2727,6 @@ 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;
}
@@ -2733,26 +2734,23 @@ 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) {
@@ -2880,8 +2878,9 @@ 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;
}
@@ -3252,10 +3251,13 @@ 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;
@@ -5406,44 +5408,19 @@ 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;
@@ -5469,7 +5446,7 @@ 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);
@@ -5484,47 +5461,18 @@ 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;
}
@@ -5564,18 +5512,17 @@ 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",
@@ -5595,6 +5542,10 @@ 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);
@@ -5772,12 +5723,6 @@ 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;
@@ -5787,32 +5732,10 @@ 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;
-
- 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 (!le32_to_cpu(rename_info->FileNameLength))
+ return -EINVAL;
- 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,
diff --git a/fs/ksmbd/vfs.c b/fs/ksmbd/vfs.c
index cef07d7fb7dc..491f1b6acd56 100644
--- a/fs/ksmbd/vfs.c
+++ b/fs/ksmbd/vfs.c
@@ -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 (dentry != child) {
- ret = -ESTALE;
- dput(dentry);
- goto out_err;
+ if (child->d_parent != parent) {
+ inode_unlock(d_inode(parent));
+ return -ENOENT;
}
- 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;
+
+ if (pathname[0] == '\0') {
+ pathname = share_conf->path;
+ root_share_path = NULL;
+ } else {
+ flags |= LOOKUP_BENEATH;
+ }
- parent = dget_parent(dentry);
- ret = ksmbd_vfs_lock_parent(idmap, parent, dentry);
- if (ret) {
- dput(parent);
- return ret;
+ filename = getname_kernel(pathname);
+ if (IS_ERR(filename))
+ return PTR_ERR(filename);
+
+ 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;
}
- ret = inode_permission(idmap, d_inode(parent),
- MAY_EXEC | MAY_WRITE);
+ 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;
- inode_unlock(d_inode(parent));
- dput(parent);
- return ret;
+ 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;
}
@@ -686,149 +655,114 @@ int ksmbd_vfs_link(struct ksmbd_work *work, const char *oldname,
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;
+ 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 (d_really_is_negative(dst_dent))
- continue;
+ if (ksmbd_override_fsids(work))
+ return -ENOMEM;
- 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;
- }
+ to = getname_kernel(newname);
+ if (IS_ERR(to)) {
+ err = PTR_ERR(to);
+ goto revert_fsids;
}
- spin_unlock(&src_dent->d_lock);
- return 0;
-}
+retry:
+ err = vfs_path_parent_lookup(to, lookup_flags | LOOKUP_BENEATH,
+ &new_path, &new_last, &new_type,
+ &share_conf->vfs_path);
+ if (err)
+ goto out1;
-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 (old_path->mnt != new_path.mnt) {
+ err = -EXDEV;
+ goto out2;
+ }
- if (!work->tcon->posix_extensions) {
- err = ksmbd_validate_entry_in_use(src_dent);
- if (err)
- return err;
+ 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;
}
- 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;
+ 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);
+ }
- if (ksmbd_override_fsids(work))
- return -ENOMEM;
+ 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;
+ }
- 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;
+ if (d_is_symlink(new_dentry)) {
+ err = -EACCES;
+ goto out4;
}
- 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);
+ if ((flags & RENAME_NOREPLACE) && d_is_positive(new_dentry)) {
+ err = -EEXIST;
+ goto out4;
}
- if (err)
- pr_err("vfs_rename failed err %d\n", err);
- if (dst_dent)
- dput(dst_dent);
-out:
- 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;
+ if (old_child == trap) {
+ err = -EINVAL;
+ goto out4;
+ }
- dst_name = extract_last_component(newname);
- if (!dst_name) {
- dst_name = newname;
- newname = "";
+ if (new_dentry == trap) {
+ err = -ENOTEMPTY;
+ goto out4;
}
- src_dent_parent = dget_parent(fp->filp->f_path.dentry);
- src_dent = fp->filp->f_path.dentry;
+ 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);
- 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;
+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;
}
- 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);
+out1:
+ putname(to);
+revert_fsids:
+ ksmbd_revert_fsids(work);
return err;
}
@@ -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;
}
@@ -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;
}
diff --git a/fs/ksmbd/vfs.h b/fs/ksmbd/vfs.h
index 9d676ab0cd25..a4ae89f3230d 100644
--- a/fs/ksmbd/vfs.h
+++ b/fs/ksmbd/vfs.h
@@ -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,
diff --git a/fs/ksmbd/vfs_cache.c b/fs/ksmbd/vfs_cache.c
index 054a7d2e0f48..2d0138e72d78 100644
--- a/fs/ksmbd/vfs_cache.c
+++ b/fs/ksmbd/vfs_cache.c
@@ -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);
diff --git a/fs/namei.c b/fs/namei.c
index 984d4f7b47dc..025fe5c52a24 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -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 @@ int do_rmdir(int dfd, struct filename *name)
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 @@ int do_unlinkat(int dfd, struct filename *name)
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 @@ int do_renameat2(int olddfd, struct filename *from, int newdfd,
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 @@ int do_renameat2(int olddfd, struct filename *from, int newdfd,
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;
diff --git a/include/linux/namei.h b/include/linux/namei.h
index 4c070fb29a91..85b12a17a23b 100644
--- a/include/linux/namei.h
+++ b/include/linux/namei.h
@@ -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 *);
--
2.25.1
^ permalink raw reply related [flat|nested] 10+ messages in thread