From: Ralph Boehme <slow@samba.org>
Date: Mon, 14 Dec 2020 10:20:46 +0000 (+0100)
Subject: smbd: use pathref fsp in change_dir_owner_to_parent()
X-Git-Tag: samba-4.14.0rc1~189
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=24a46b9db9561c49996a2e77320228a7d22de08a;p=thirdparty%2Fsamba.git

smbd: use pathref fsp in change_dir_owner_to_parent()

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
---

diff --git a/source3/smbd/open.c b/source3/smbd/open.c
index fdbcb7c206c..20f39ee2414 100644
--- a/source3/smbd/open.c
+++ b/source3/smbd/open.c
@@ -1023,117 +1023,50 @@ static NTSTATUS change_dir_owner_to_parent(connection_struct *conn,
 					struct smb_filename *smb_dname,
 					SMB_STRUCT_STAT *psbuf)
 {
-	struct smb_filename *smb_fname_cwd = NULL;
-	struct smb_filename *saved_dir_fname = NULL;
-	TALLOC_CTX *ctx = talloc_tos();
-	NTSTATUS status = NT_STATUS_OK;
 	int ret;
 
 	ret = SMB_VFS_STAT(conn, smb_fname_parent);
 	if (ret == -1) {
-		status = map_nt_error_from_unix(errno);
 		DEBUG(0,("change_dir_owner_to_parent: failed to stat parent "
 			 "directory %s. Error was %s\n",
 			 smb_fname_str_dbg(smb_fname_parent),
 			 strerror(errno)));
-		goto out;
-	}
-
-	/* We've already done an lstat into psbuf, and we know it's a
-	   directory. If we can cd into the directory and the dev/ino
-	   are the same then we can safely chown without races as
-	   we're locking the directory in place by being in it.  This
-	   should work on any UNIX (thanks tridge :-). JRA.
-	*/
-
-	saved_dir_fname = vfs_GetWd(ctx,conn);
-	if (!saved_dir_fname) {
-		status = map_nt_error_from_unix(errno);
-		DEBUG(0,("change_dir_owner_to_parent: failed to get "
-			 "current working directory. Error was %s\n",
-			 strerror(errno)));
-		goto out;
-	}
-
-	/* Chdir into the new path. */
-	if (vfs_ChDir(conn, smb_dname) == -1) {
-		status = map_nt_error_from_unix(errno);
-		DEBUG(0,("change_dir_owner_to_parent: failed to change "
-			 "current working directory to %s. Error "
-			 "was %s\n", smb_dname->base_name, strerror(errno) ));
-		goto chdir;
-	}
-
-	smb_fname_cwd = synthetic_smb_fname(ctx,
-					    ".",
-					    NULL,
-					    NULL,
-					    smb_dname->twrp,
-					    0);
-	if (smb_fname_cwd == NULL) {
-		status = NT_STATUS_NO_MEMORY;
-		goto chdir;
-	}
-
-	ret = SMB_VFS_STAT(conn, smb_fname_cwd);
-	if (ret == -1) {
-		status = map_nt_error_from_unix(errno);
-		DEBUG(0,("change_dir_owner_to_parent: failed to stat "
-			 "directory '.' (%s) Error was %s\n",
-			 smb_dname->base_name, strerror(errno)));
-		goto chdir;
-	}
-
-	/* Ensure we're pointing at the same place. */
-	if (smb_fname_cwd->st.st_ex_dev != psbuf->st_ex_dev ||
-	    smb_fname_cwd->st.st_ex_ino != psbuf->st_ex_ino) {
-		DEBUG(0,("change_dir_owner_to_parent: "
-			 "device/inode on directory %s changed. "
-			 "Refusing to chown !\n",
-			smb_dname->base_name ));
-		status = NT_STATUS_ACCESS_DENIED;
-		goto chdir;
+		return map_nt_error_from_unix(errno);
 	}
 
-	if (smb_fname_parent->st.st_ex_uid == smb_fname_cwd->st.st_ex_uid) {
+	if (smb_fname_parent->st.st_ex_uid == smb_dname->st.st_ex_uid) {
 		/* Already this uid - no need to change. */
 		DEBUG(10,("change_dir_owner_to_parent: directory %s "
 			"is already owned by uid %d\n",
 			smb_dname->base_name,
-			(int)smb_fname_cwd->st.st_ex_uid ));
-		status = NT_STATUS_OK;
-		goto chdir;
+			(int)smb_dname->st.st_ex_uid ));
+		return NT_STATUS_OK;
 	}
 
 	become_root();
-	ret = SMB_VFS_LCHOWN(conn,
-			smb_fname_cwd,
-			smb_fname_parent->st.st_ex_uid,
-			(gid_t)-1);
+	ret = SMB_VFS_FCHOWN(smb_dname->fsp,
+			     smb_fname_parent->st.st_ex_uid,
+			     (gid_t)-1);
 	unbecome_root();
 	if (ret == -1) {
-		status = map_nt_error_from_unix(errno);
 		DEBUG(10,("change_dir_owner_to_parent: failed to chown "
 			  "directory %s to parent directory uid %u. "
 			  "Error was %s\n",
 			  smb_dname->base_name,
 			  (unsigned int)smb_fname_parent->st.st_ex_uid,
 			  strerror(errno) ));
-	} else {
-		DEBUG(10,("change_dir_owner_to_parent: changed ownership of new "
-			"directory %s to parent directory uid %u.\n",
-			smb_dname->base_name,
-			(unsigned int)smb_fname_parent->st.st_ex_uid ));
-		/* Ensure the uid entry is updated. */
-		psbuf->st_ex_uid = smb_fname_parent->st.st_ex_uid;
+		return map_nt_error_from_unix(errno);
 	}
 
- chdir:
-	vfs_ChDir(conn, saved_dir_fname);
- out:
-	TALLOC_FREE(saved_dir_fname);
-	TALLOC_FREE(smb_fname_cwd);
-	return status;
+	DBG_DEBUG("changed ownership of new "
+		  "directory %s to parent directory uid %u.\n",
+		  smb_dname->base_name,
+		  (unsigned int)smb_fname_parent->st.st_ex_uid);
+
+	/* Ensure the uid entry is updated. */
+	psbuf->st_ex_uid = smb_fname_parent->st.st_ex_uid;
+
+	return NT_STATUS_OK;
 }
 
 /****************************************************************************