Use *at() functions to pin the directory operating in to avoid being redirected by unprivileged users replacing parts of paths by symlinks to privileged files.
		
			
				
	
	
		
			102 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			102 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * SPDX-FileCopyrightText: 1991 - 1994, Julianne Frances Haugh
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 * SPDX-FileCopyrightText: 1996 - 2001, Marek Michałkiewicz
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 * SPDX-FileCopyrightText: 2003 - 2006, Tomasz Kłoczko
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 * SPDX-FileCopyrightText: 2007 - 2010, Nicolas François
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 *
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 * SPDX-License-Identifier: BSD-3-Clause
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 */
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#include <config.h>
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#ident "$Id$"
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#include <fcntl.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <dirent.h>
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#include <unistd.h>
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#include "prototypes.h"
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#include "defines.h"
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static int remove_tree_at (int at_fd, const char *path, bool remove_root)
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{
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	DIR *dir;
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	const struct dirent *ent;
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	int dir_fd, rc = 0;
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	dir_fd = openat (at_fd, path, O_RDONLY | O_DIRECTORY | O_NOFOLLOW | O_CLOEXEC);
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	if (dir_fd < 0) {
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		return -1;
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	}
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	dir = fdopendir (dir_fd);
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	if (!dir) {
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		(void) close (dir_fd);
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		return -1;
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	}
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	/*
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	 * Open the source directory and delete each entry.
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	 */
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	while ((ent = readdir (dir))) {
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		struct stat ent_sb;
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		/*
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		 * Skip the "." and ".." entries
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		 */
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		if (strcmp (ent->d_name, ".") == 0 ||
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		    strcmp (ent->d_name, "..") == 0) {
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			continue;
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		}
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		rc = fstatat (dirfd(dir), ent->d_name, &ent_sb, AT_SYMLINK_NOFOLLOW);
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		if (rc < 0) {
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			break;
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		}
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		if (S_ISDIR (ent_sb.st_mode)) {
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			/*
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			 * Recursively delete this directory.
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			 */
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			if (remove_tree_at (dirfd(dir), ent->d_name, true) != 0) {
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				rc = -1;
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				break;
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			}
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		} else {
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			/*
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			 * Delete the file.
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			 */
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			if (unlinkat (dirfd(dir), ent->d_name, 0) != 0) {
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				rc = -1;
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				break;
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			}
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		}
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	}
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	(void) closedir (dir);
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	if (remove_root && (0 == rc)) {
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		if (unlinkat (at_fd, path, AT_REMOVEDIR) != 0) {
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			rc = -1;
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		}
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	}
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	return rc;
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}
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/*
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 * remove_tree - delete a directory tree
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 *
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 *	remove_tree() walks a directory tree and deletes all the files
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 *	and directories.
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 *	At the end, it deletes the root directory itself.
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 */
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int remove_tree (const char *root, bool remove_root)
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{
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	return remove_tree_at (AT_FDCWD, root, remove_root);
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}
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