sanitize struct filename and lookup flags handling in statx

and friends
 
 Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'pull-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull statx updates from Al Viro:
 "Sanitize struct filename and lookup flags handling in statx and
  friends"

* tag 'pull-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  libfs: kill empty_dir_getattr()
  fs: Simplify getattr interface function checking AT_GETATTR_NOSEC flag
  fs/stat.c: switch to CLASS(fd_raw)
  kill getname_statx_lookup_flags()
  io_statx_prep(): use getname_uflags()

fs/ecryptfs/inode.c

@@ -1008,14 +1008,6 @@ static int ecryptfs_getattr_link(struct mnt_idmap *idmap,
 	return rc;
 }
 
-static int ecryptfs_do_getattr(const struct path *path, struct kstat *stat,
-			       u32 request_mask, unsigned int flags)
-{
-	if (flags & AT_GETATTR_NOSEC)
-		return vfs_getattr_nosec(path, stat, request_mask, flags);
-	return vfs_getattr(path, stat, request_mask, flags);
-}
-
 static int ecryptfs_getattr(struct mnt_idmap *idmap,
 			    const struct path *path, struct kstat *stat,
 			    u32 request_mask, unsigned int flags)
@@ -1024,7 +1016,7 @@ static int ecryptfs_getattr(struct mnt_idmap *idmap,
 	struct kstat lower_stat;
 	int rc;
 
-	rc = ecryptfs_do_getattr(ecryptfs_dentry_to_lower_path(dentry),
+	rc = vfs_getattr_nosec(ecryptfs_dentry_to_lower_path(dentry),
 			       &lower_stat, request_mask, flags);
 	if (!rc) {
 		fsstack_copy_attr_all(d_inode(dentry),

fs/internal.h

@@ -246,7 +246,6 @@ int open_namespace(struct ns_common *ns);
  * fs/stat.c:
  */
 
-int getname_statx_lookup_flags(int flags);
 int do_statx(int dfd, struct filename *filename, unsigned int flags,
 	     unsigned int mask, struct statx __user *buffer);
 int do_statx_fd(int fd, unsigned int flags, unsigned int mask,

fs/libfs.c

@@ -1715,15 +1715,6 @@ static struct dentry *empty_dir_lookup(struct inode *dir, struct dentry *dentry,
 	return ERR_PTR(-ENOENT);
 }
 
-static int empty_dir_getattr(struct mnt_idmap *idmap,
-			     const struct path *path, struct kstat *stat,
-			     u32 request_mask, unsigned int query_flags)
-{
-	struct inode *inode = d_inode(path->dentry);
-	generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
-	return 0;
-}
-
 static int empty_dir_setattr(struct mnt_idmap *idmap,
 			     struct dentry *dentry, struct iattr *attr)
 {
@@ -1737,9 +1728,7 @@ static ssize_t empty_dir_listxattr(struct dentry *dentry, char *list, size_t siz
 
 static const struct inode_operations empty_dir_inode_operations = {
 	.lookup		= empty_dir_lookup,
-	.permission	= generic_permission,
 	.setattr	= empty_dir_setattr,
-	.getattr	= empty_dir_getattr,
 	.listxattr	= empty_dir_listxattr,
 };
 

fs/overlayfs/inode.c

@@ -170,7 +170,7 @@ int ovl_getattr(struct mnt_idmap *idmap, const struct path *path,
 
 	type = ovl_path_real(dentry, &realpath);
 	old_cred = ovl_override_creds(dentry->d_sb);
-	err = ovl_do_getattr(&realpath, stat, request_mask, flags);
+	err = vfs_getattr_nosec(&realpath, stat, request_mask, flags);
 	if (err)
 		goto out;
 
@@ -195,7 +195,7 @@ int ovl_getattr(struct mnt_idmap *idmap, const struct path *path,
 					(!is_dir ? STATX_NLINK : 0);
 
 			ovl_path_lower(dentry, &realpath);
-			err = ovl_do_getattr(&realpath, &lowerstat, lowermask,
+			err = vfs_getattr_nosec(&realpath, &lowerstat, lowermask,
 						flags);
 			if (err)
 				goto out;
@@ -248,7 +248,7 @@ int ovl_getattr(struct mnt_idmap *idmap, const struct path *path,
 
 			ovl_path_lowerdata(dentry, &realpath);
 			if (realpath.dentry) {
-				err = ovl_do_getattr(&realpath, &lowerdatastat,
+				err = vfs_getattr_nosec(&realpath, &lowerdatastat,
 							lowermask, flags);
 				if (err)
 					goto out;

fs/overlayfs/overlayfs.h

@@ -412,14 +412,6 @@ static inline bool ovl_open_flags_need_copy_up(int flags)
 	return ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC));
 }
 
-static inline int ovl_do_getattr(const struct path *path, struct kstat *stat,
-				 u32 request_mask, unsigned int flags)
-{
-	if (flags & AT_GETATTR_NOSEC)
-		return vfs_getattr_nosec(path, stat, request_mask, flags);
-	return vfs_getattr(path, stat, request_mask, flags);
-}
-
 /* util.c */
 int ovl_get_write_access(struct dentry *dentry);
 void ovl_put_write_access(struct dentry *dentry);

fs/stat.c

@@ -207,7 +207,7 @@ int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
 	if (inode->i_op->getattr)
 		return inode->i_op->getattr(idmap, path, stat,
 					    request_mask,
-					    query_flags | AT_GETATTR_NOSEC);
+					    query_flags);
 
 	generic_fillattr(idmap, request_mask, inode, stat);
 	return 0;
@@ -240,9 +240,6 @@ int vfs_getattr(const struct path *path, struct kstat *stat,
 {
 	int retval;
 
-	if (WARN_ON_ONCE(query_flags & AT_GETATTR_NOSEC))
-		return -EPERM;
-
 	retval = security_inode_getattr(path);
 	if (retval)
 		return retval;
@@ -262,18 +259,13 @@ EXPORT_SYMBOL(vfs_getattr);
  */
 int vfs_fstat(int fd, struct kstat *stat)
 {
-	struct fd f;
+	CLASS(fd_raw, f)(fd);
-	int error;
+	if (fd_empty(f))
-
-	f = fdget_raw(fd);
-	if (!fd_file(f))
 		return -EBADF;
-	error = vfs_getattr(&fd_file(f)->f_path, stat, STATX_BASIC_STATS, 0);
+	return vfs_getattr(&fd_file(f)->f_path, stat, STATX_BASIC_STATS, 0);
-	fdput(f);
-	return error;
 }
 
-int getname_statx_lookup_flags(int flags)
+static int statx_lookup_flags(int flags)
 {
 	int lookup_flags = 0;
 
@@ -281,8 +273,6 @@ int getname_statx_lookup_flags(int flags)
 		lookup_flags |= LOOKUP_FOLLOW;
 	if (!(flags & AT_NO_AUTOMOUNT))
 		lookup_flags |= LOOKUP_AUTOMOUNT;
-	if (flags & AT_EMPTY_PATH)
-		lookup_flags |= LOOKUP_EMPTY;
 
 	return lookup_flags;
 }
@@ -319,7 +309,7 @@ static int vfs_statx_fd(int fd, int flags, struct kstat *stat,
 			  u32 request_mask)
 {
 	CLASS(fd_raw, f)(fd);
-	if (!fd_file(f))
+	if (fd_empty(f))
 		return -EBADF;
 	return vfs_statx_path(&fd_file(f)->f_path, flags, stat, request_mask);
 }
@@ -343,7 +333,7 @@ static int vfs_statx(int dfd, struct filename *filename, int flags,
 	      struct kstat *stat, u32 request_mask)
 {
 	struct path path;
-	unsigned int lookup_flags = getname_statx_lookup_flags(flags);
+	unsigned int lookup_flags = statx_lookup_flags(flags);
 	int error;
 
 	if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT | AT_EMPTY_PATH |

include/uapi/linux/fcntl.h

@@ -154,8 +154,4 @@
 					   usable with open_by_handle_at(2). */
 #define AT_HANDLE_MNT_ID_UNIQUE	0x001	/* Return the u64 unique mount ID. */
 
-#if defined(__KERNEL__)
-#define AT_GETATTR_NOSEC	0x80000000
-#endif
-
 #endif /* _UAPI_LINUX_FCNTL_H */

io_uring/statx.c

@@ -36,8 +36,7 @@ int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 	sx->buffer = u64_to_user_ptr(READ_ONCE(sqe->addr2));
 	sx->flags = READ_ONCE(sqe->statx_flags);
 
-	sx->filename = getname_flags(path,
+	sx->filename = getname_uflags(path, sx->flags);
-				     getname_statx_lookup_flags(sx->flags));
 
 	if (IS_ERR(sx->filename)) {
 		int ret = PTR_ERR(sx->filename);