Reported by clang-analyzer. After reading the linux man-pages vfork(2) manpage I came to the conclusion that it's better to change the behaviour of the original source (NetBSD) and change this to use fork(2).
		
			
				
	
	
		
			140 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			140 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*-
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 * Copyright (c) 2003 The NetBSD Foundation, Inc.
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 * All rights reserved.
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 *
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 * This code is derived from software contributed to The NetBSD Foundation
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 * by Matthias Scheler.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in the
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 *    documentation and/or other materials provided with the distribution.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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 * POSSIBILITY OF SUCH DAMAGE.
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 */
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#define _BSD_SOURCE	/* for vfork and chroot */
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#define _DEFAULT_SOURCE	/* glibc>=2.20 */
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#include <sys/types.h>
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#include <unistd.h>
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#include <sys/wait.h>
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#include <errno.h>
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#include <stdarg.h>
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#include <stdlib.h>
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#include <string.h>
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#undef _DEFAULT_SOURCE
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#undef _BSD_SOURCE
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#include "xbps_api_impl.h"
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static int
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pfcexec(struct xbps_handle *xhp, const char *file, const char **argv)
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{
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	pid_t child;
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	int status;
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	child = fork();
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	switch (child) {
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	case 0:
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		/*
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		 * If rootdir != / and uid==0 and bin/sh exists,
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		 * change root directory and exec command.
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		 */
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		if (strcmp(xhp->rootdir, "/")) {
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			if ((geteuid() == 0) && (access("bin/sh", X_OK) == 0)) {
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				if (chroot(xhp->rootdir) == -1) {
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					xbps_dbg_printf(xhp, "%s: chroot() "
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					    "failed: %s\n", *argv, strerror(errno));
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					_exit(errno);
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				}
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				if (chdir("/") == -1) {
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					xbps_dbg_printf(xhp, "%s: chdir() "
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					    "failed: %s\n", *argv, strerror(errno));
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					_exit(errno);
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				}
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			}
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		}
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		umask(022);
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		(void)execv(file, __UNCONST(argv));
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		_exit(errno);
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		/* NOTREACHED */
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	case -1:
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		return -1;
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	}
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	while (waitpid(child, &status, 0) < 0) {
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		if (errno != EINTR)
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			return -1;
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	}
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	if (!WIFEXITED(status))
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		return -1;
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	return WEXITSTATUS(status);
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}
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static int
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vfcexec(struct xbps_handle *xhp, const char *arg, va_list ap)
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{
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	const char **argv;
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	size_t argv_size, argc;
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	int retval;
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	argv_size = 16;
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	if ((argv = malloc(argv_size * sizeof(*argv))) == NULL) {
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		errno = ENOMEM;
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		return -1;
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	}
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	argv[0] = arg;
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	argc = 1;
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	do {
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		if (argc == argv_size) {
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			argv_size *= 2;
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			argv = realloc(argv, argv_size * sizeof(*argv));
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			if (argv == NULL) {
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				errno = ENOMEM;
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				return -1;
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			}
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		}
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		arg = va_arg(ap, const char *);
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		argv[argc++] = arg;
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	} while (arg != NULL);
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	retval = pfcexec(xhp, argv[0], argv);
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	free(argv);
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	return retval;
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}
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int HIDDEN
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xbps_file_exec(struct xbps_handle *xhp, const char *arg, ...)
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{
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	va_list	ap;
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	int	result;
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	va_start(ap, arg);
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	result = vfcexec(xhp, arg, ap);
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	va_end(ap);
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	return result;
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}
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