[PATCH 6.1 018/100] ksmbd: fix racy issue from using ->d_parent and ->d_name

6.1-stable review patch. If anyone has any objections, please let me know.

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From: Namjae Jeon linkinjeon@kernel.org

[ Upstream commit 74d7970febf7e9005375aeda0df821d2edffc9f7 ]

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 Signed-off-by: Sasha Levin sashal@kernel.org --- fs/namei.c | 57 +++-- fs/smb/server/smb2pdu.c | 147 +++---------- fs/smb/server/vfs.c | 435 ++++++++++++++++---------------------- fs/smb/server/vfs.h | 19 +- fs/smb/server/vfs_cache.c | 5 +- include/linux/namei.h | 6 + 6 files changed, 283 insertions(+), 386 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c index 6daaf84567195..b5578f4ce5d6e 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -253,6 +253,7 @@ 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;

@@ -4214,7 +4245,7 @@ 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; @@ -4348,7 +4379,7 @@ 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)) { struct user_namespace *mnt_userns; @@ -4922,7 +4953,8 @@ 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; @@ -4930,7 +4962,8 @@ 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/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index ca57e85abf915..fe10c75f6f2b9 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -2506,7 +2506,7 @@ 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); @@ -2797,8 +2797,10 @@ 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 @@ -2807,7 +2809,6 @@ 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; }

@@ -2815,26 +2816,23 @@ 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; + user_ns = mnt_user_ns(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; - user_ns = mnt_user_ns(path.mnt); } + if (stream_name) { if (req->CreateOptions & FILE_DIRECTORY_FILE_LE) { if (s_type == DATA_STREAM) { @@ -2962,8 +2960,9 @@ int smb2_open(struct ksmbd_work *work)

if ((daccess & FILE_DELETE_LE) || (req->CreateOptions & FILE_DELETE_ON_CLOSE_LE)) { - rc = ksmbd_vfs_may_delete(user_ns, - path.dentry); + rc = inode_permission(user_ns, + d_inode(path.dentry->d_parent), + MAY_EXEC | MAY_WRITE); if (rc) goto err_out; } @@ -3334,10 +3333,13 @@ 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; @@ -5481,44 +5483,19 @@ int smb2_echo(struct ksmbd_work *work)

static int smb2_rename(struct ksmbd_work *work, struct ksmbd_file *fp, - struct user_namespace *user_ns, 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; @@ -5544,7 +5521,7 @@ static int smb2_rename(struct ksmbd_work *work, if (rc) goto out;

- rc = ksmbd_vfs_setxattr(user_ns, + rc = ksmbd_vfs_setxattr(file_mnt_user_ns(fp->filp), fp->filp->f_path.dentry, xattr_stream_name, NULL, 0, 0); @@ -5559,47 +5536,18 @@ 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; }

@@ -5639,18 +5587,17 @@ 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", @@ -5670,6 +5617,10 @@ 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); @@ -5847,12 +5798,6 @@ 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 user_namespace *user_ns; - 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; @@ -5862,32 +5807,10 @@ static int set_rename_info(struct ksmbd_work *work, struct ksmbd_file *fp, le32_to_cpu(rename_info->FileNameLength)) return -EINVAL;

- user_ns = file_mnt_user_ns(fp->filp); - if (ksmbd_stream_fd(fp)) - goto next; - - parent = dget_parent(dentry); - ret = ksmbd_vfs_lock_parent(user_ns, 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, user_ns, 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/smb/server/vfs.c b/fs/smb/server/vfs.c index 187d31d984946..58a6665f1c3ab 100644 --- a/fs/smb/server/vfs.c +++ b/fs/smb/server/vfs.c @@ -17,6 +17,7 @@ #include <linux/vmalloc.h> #include <linux/sched/xacct.h> #include <linux/crc32c.h> +#include <linux/namei.h>

#include "../../internal.h" /* for vfs_path_lookup */

@@ -36,19 +37,6 @@ #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) @@ -62,65 +50,77 @@ 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 user_namespace *user_ns, 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(user_ns, 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 user_namespace *user_ns, - 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(user_ns, 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(user_ns, 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 user_namespace *user_ns, struct dentry *dentry, __le32 *daccess) { - struct dentry *parent; int ret = 0;

*daccess = cpu_to_le32(FILE_READ_ATTRIBUTES | READ_CONTROL); @@ -137,18 +137,9 @@ int ksmbd_vfs_query_maximal_access(struct user_namespace *user_ns, if (!inode_permission(user_ns, d_inode(dentry), MAY_OPEN | MAY_EXEC)) *daccess |= FILE_EXECUTE_LE;

- parent = dget_parent(dentry); - ret = ksmbd_vfs_lock_parent(user_ns, parent, dentry); - if (ret) { - dput(parent); - return ret; - } - - if (!inode_permission(user_ns, d_inode(parent), MAY_EXEC | MAY_WRITE)) + if (!inode_permission(user_ns, d_inode(dentry->d_parent), MAY_EXEC | MAY_WRITE)) *daccess |= FILE_DELETE_LE;

- inode_unlock(d_inode(parent)); - dput(parent); return ret; }

@@ -581,54 +572,32 @@ 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 user_namespace *user_ns; - 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; - } - - user_ns = mnt_user_ns(path.mnt); - parent = dget_parent(path.dentry); - err = ksmbd_vfs_lock_parent(user_ns, 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(user_ns, d_inode(parent), path.dentry); + user_ns = mnt_user_ns(path->mnt); + if (S_ISDIR(d_inode(path->dentry)->i_mode)) { + err = vfs_rmdir(user_ns, 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(user_ns, d_inode(parent), path.dentry, NULL); + err = vfs_unlink(user_ns, 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; } @@ -687,149 +656,114 @@ 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 user_namespace *src_user_ns, - struct dentry *src_dent_parent, - struct dentry *src_dent, - struct user_namespace *dst_user_ns, - 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_user_ns, 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_userns = src_user_ns, - .old_dir = d_inode(src_dent_parent), - .old_dentry = src_dent, - .new_mnt_userns = dst_user_ns, - .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 user_namespace *user_ns; - 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_userns = mnt_user_ns(old_path->mnt), + rd.old_dir = d_inode(old_parent), + rd.old_dentry = old_child, + rd.new_mnt_userns = mnt_user_ns(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); - user_ns = file_mnt_user_ns(fp->filp); - src_child = lookup_one(user_ns, 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, - user_ns, - src_dent_parent, - src_dent, - mnt_user_ns(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; }

@@ -1080,14 +1014,16 @@ int ksmbd_vfs_remove_xattr(struct user_namespace *user_ns, return vfs_removexattr(user_ns, dentry, attr_name); }

-int ksmbd_vfs_unlink(struct user_namespace *user_ns, - 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 user_namespace *user_ns = file_mnt_user_ns(filp);

- err = ksmbd_vfs_lock_parent(user_ns, 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)) @@ -1099,6 +1035,8 @@ int ksmbd_vfs_unlink(struct user_namespace *user_ns, inode_unlock(d_inode(dir)); if (err) ksmbd_debug(VFS, "failed to delete, err %d\n", err); +out: + dput(dir);

return err; } @@ -1201,7 +1139,7 @@ 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 @@ -1209,24 +1147,20 @@ 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); @@ -1236,10 +1170,10 @@ 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; @@ -1248,12 +1182,11 @@ 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';

@@ -1261,23 +1194,31 @@ 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/smb/server/vfs.h b/fs/smb/server/vfs.h index 593059ca85112..7660565ac2770 100644 --- a/fs/smb/server/vfs.h +++ b/fs/smb/server/vfs.h @@ -71,9 +71,7 @@ struct ksmbd_kstat { __le32 file_attributes; };

-int ksmbd_vfs_lock_parent(struct user_namespace *user_ns, struct dentry *parent, - struct dentry *child); -int ksmbd_vfs_may_delete(struct user_namespace *user_ns, struct dentry *dentry); +int ksmbd_vfs_lock_parent(struct dentry *parent, struct dentry *child); int ksmbd_vfs_query_maximal_access(struct user_namespace *user_ns, 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 user_namespace *user_ns, 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 user_namespace *user_ns, - 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 user_namespace *user_ns, diff --git a/fs/smb/server/vfs_cache.c b/fs/smb/server/vfs_cache.c index 6ec6c129465d3..bafb34d4b5bbb 100644 --- a/fs/smb/server/vfs_cache.c +++ b/fs/smb/server/vfs_cache.c @@ -243,7 +243,6 @@ 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; @@ -262,11 +261,9 @@ 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_user_ns(filp), dir, dentry); + ksmbd_vfs_unlink(filp); write_lock(&ci->m_lock); } write_unlock(&ci->m_lock); diff --git a/include/linux/namei.h b/include/linux/namei.h index 2b66021c740dd..5c0149603dc3d 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);

extern struct dentry *try_lookup_one_len(const char *, struct dentry *, int); extern struct dentry *lookup_one_len(const char *, struct dentry *, int);