360 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			360 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0
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| /*
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|  * Landlock tests - Common user space base
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|  *
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|  * Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net>
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|  * Copyright © 2019-2020 ANSSI
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|  */
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| 
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| #define _GNU_SOURCE
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| #include <errno.h>
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| #include <fcntl.h>
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| #include <linux/landlock.h>
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| #include <string.h>
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| #include <sys/prctl.h>
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| #include <sys/socket.h>
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| #include <sys/types.h>
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| 
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| #include "common.h"
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| 
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| #ifndef O_PATH
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| #define O_PATH 010000000
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| #endif
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| 
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| TEST(inconsistent_attr)
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| {
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| 	const long page_size = sysconf(_SC_PAGESIZE);
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| 	char *const buf = malloc(page_size + 1);
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| 	struct landlock_ruleset_attr *const ruleset_attr = (void *)buf;
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| 
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| 	ASSERT_NE(NULL, buf);
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| 
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| 	/* Checks copy_from_user(). */
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| 	ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, 0, 0));
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| 	/* The size if less than sizeof(struct landlock_attr_enforce). */
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| 	ASSERT_EQ(EINVAL, errno);
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| 	ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, 1, 0));
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| 	ASSERT_EQ(EINVAL, errno);
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| 	ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, 7, 0));
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| 	ASSERT_EQ(EINVAL, errno);
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| 
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| 	ASSERT_EQ(-1, landlock_create_ruleset(NULL, 1, 0));
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| 	/* The size if less than sizeof(struct landlock_attr_enforce). */
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| 	ASSERT_EQ(EFAULT, errno);
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| 
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| 	ASSERT_EQ(-1, landlock_create_ruleset(
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| 			      NULL, sizeof(struct landlock_ruleset_attr), 0));
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| 	ASSERT_EQ(EFAULT, errno);
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| 
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| 	ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, page_size + 1, 0));
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| 	ASSERT_EQ(E2BIG, errno);
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| 
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| 	/* Checks minimal valid attribute size. */
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| 	ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, 8, 0));
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| 	ASSERT_EQ(ENOMSG, errno);
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| 	ASSERT_EQ(-1, landlock_create_ruleset(
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| 			      ruleset_attr,
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| 			      sizeof(struct landlock_ruleset_attr), 0));
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| 	ASSERT_EQ(ENOMSG, errno);
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| 	ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, page_size, 0));
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| 	ASSERT_EQ(ENOMSG, errno);
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| 
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| 	/* Checks non-zero value. */
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| 	buf[page_size - 2] = '.';
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| 	ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, page_size, 0));
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| 	ASSERT_EQ(E2BIG, errno);
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| 
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| 	ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, page_size + 1, 0));
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| 	ASSERT_EQ(E2BIG, errno);
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| 
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| 	free(buf);
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| }
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| 
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| TEST(abi_version)
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| {
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| 	const struct landlock_ruleset_attr ruleset_attr = {
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| 		.handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE,
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| 	};
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| 	ASSERT_EQ(2, landlock_create_ruleset(NULL, 0,
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| 					     LANDLOCK_CREATE_RULESET_VERSION));
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| 
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| 	ASSERT_EQ(-1, landlock_create_ruleset(&ruleset_attr, 0,
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| 					      LANDLOCK_CREATE_RULESET_VERSION));
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| 	ASSERT_EQ(EINVAL, errno);
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| 
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| 	ASSERT_EQ(-1, landlock_create_ruleset(NULL, sizeof(ruleset_attr),
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| 					      LANDLOCK_CREATE_RULESET_VERSION));
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| 	ASSERT_EQ(EINVAL, errno);
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| 
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| 	ASSERT_EQ(-1,
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| 		  landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr),
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| 					  LANDLOCK_CREATE_RULESET_VERSION));
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| 	ASSERT_EQ(EINVAL, errno);
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| 
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| 	ASSERT_EQ(-1, landlock_create_ruleset(NULL, 0,
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| 					      LANDLOCK_CREATE_RULESET_VERSION |
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| 						      1 << 31));
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| 	ASSERT_EQ(EINVAL, errno);
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| }
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| 
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| /* Tests ordering of syscall argument checks. */
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| TEST(create_ruleset_checks_ordering)
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| {
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| 	const int last_flag = LANDLOCK_CREATE_RULESET_VERSION;
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| 	const int invalid_flag = last_flag << 1;
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| 	int ruleset_fd;
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| 	const struct landlock_ruleset_attr ruleset_attr = {
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| 		.handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE,
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| 	};
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| 
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| 	/* Checks priority for invalid flags. */
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| 	ASSERT_EQ(-1, landlock_create_ruleset(NULL, 0, invalid_flag));
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| 	ASSERT_EQ(EINVAL, errno);
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| 
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| 	ASSERT_EQ(-1, landlock_create_ruleset(&ruleset_attr, 0, invalid_flag));
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| 	ASSERT_EQ(EINVAL, errno);
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| 
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| 	ASSERT_EQ(-1, landlock_create_ruleset(NULL, sizeof(ruleset_attr),
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| 					      invalid_flag));
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| 	ASSERT_EQ(EINVAL, errno);
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| 
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| 	ASSERT_EQ(-1,
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| 		  landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr),
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| 					  invalid_flag));
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| 	ASSERT_EQ(EINVAL, errno);
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| 
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| 	/* Checks too big ruleset_attr size. */
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| 	ASSERT_EQ(-1, landlock_create_ruleset(&ruleset_attr, -1, 0));
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| 	ASSERT_EQ(E2BIG, errno);
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| 
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| 	/* Checks too small ruleset_attr size. */
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| 	ASSERT_EQ(-1, landlock_create_ruleset(&ruleset_attr, 0, 0));
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| 	ASSERT_EQ(EINVAL, errno);
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| 	ASSERT_EQ(-1, landlock_create_ruleset(&ruleset_attr, 1, 0));
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| 	ASSERT_EQ(EINVAL, errno);
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| 
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| 	/* Checks valid call. */
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| 	ruleset_fd =
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| 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
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| 	ASSERT_LE(0, ruleset_fd);
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| 	ASSERT_EQ(0, close(ruleset_fd));
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| }
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| 
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| /* Tests ordering of syscall argument checks. */
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| TEST(add_rule_checks_ordering)
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| {
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| 	const struct landlock_ruleset_attr ruleset_attr = {
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| 		.handled_access_fs = LANDLOCK_ACCESS_FS_EXECUTE,
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| 	};
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| 	struct landlock_path_beneath_attr path_beneath_attr = {
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| 		.allowed_access = LANDLOCK_ACCESS_FS_EXECUTE,
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| 		.parent_fd = -1,
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| 	};
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| 	const int ruleset_fd =
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| 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
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| 
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| 	ASSERT_LE(0, ruleset_fd);
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| 
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| 	/* Checks invalid flags. */
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| 	ASSERT_EQ(-1, landlock_add_rule(-1, 0, NULL, 1));
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| 	ASSERT_EQ(EINVAL, errno);
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| 
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| 	/* Checks invalid ruleset FD. */
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| 	ASSERT_EQ(-1, landlock_add_rule(-1, 0, NULL, 0));
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| 	ASSERT_EQ(EBADF, errno);
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| 
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| 	/* Checks invalid rule type. */
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| 	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, 0, NULL, 0));
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| 	ASSERT_EQ(EINVAL, errno);
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| 
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| 	/* Checks invalid rule attr. */
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| 	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
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| 					NULL, 0));
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| 	ASSERT_EQ(EFAULT, errno);
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| 
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| 	/* Checks invalid path_beneath.parent_fd. */
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| 	ASSERT_EQ(-1, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
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| 					&path_beneath_attr, 0));
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| 	ASSERT_EQ(EBADF, errno);
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| 
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| 	/* Checks valid call. */
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| 	path_beneath_attr.parent_fd =
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| 		open("/tmp", O_PATH | O_NOFOLLOW | O_DIRECTORY | O_CLOEXEC);
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| 	ASSERT_LE(0, path_beneath_attr.parent_fd);
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| 	ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
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| 				       &path_beneath_attr, 0));
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| 	ASSERT_EQ(0, close(path_beneath_attr.parent_fd));
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| 	ASSERT_EQ(0, close(ruleset_fd));
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| }
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| 
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| /* Tests ordering of syscall argument and permission checks. */
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| TEST(restrict_self_checks_ordering)
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| {
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| 	const struct landlock_ruleset_attr ruleset_attr = {
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| 		.handled_access_fs = LANDLOCK_ACCESS_FS_EXECUTE,
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| 	};
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| 	struct landlock_path_beneath_attr path_beneath_attr = {
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| 		.allowed_access = LANDLOCK_ACCESS_FS_EXECUTE,
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| 		.parent_fd = -1,
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| 	};
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| 	const int ruleset_fd =
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| 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
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| 
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| 	ASSERT_LE(0, ruleset_fd);
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| 	path_beneath_attr.parent_fd =
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| 		open("/tmp", O_PATH | O_NOFOLLOW | O_DIRECTORY | O_CLOEXEC);
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| 	ASSERT_LE(0, path_beneath_attr.parent_fd);
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| 	ASSERT_EQ(0, landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
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| 				       &path_beneath_attr, 0));
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| 	ASSERT_EQ(0, close(path_beneath_attr.parent_fd));
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| 
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| 	/* Checks unprivileged enforcement without no_new_privs. */
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| 	drop_caps(_metadata);
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| 	ASSERT_EQ(-1, landlock_restrict_self(-1, -1));
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| 	ASSERT_EQ(EPERM, errno);
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| 	ASSERT_EQ(-1, landlock_restrict_self(-1, 0));
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| 	ASSERT_EQ(EPERM, errno);
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| 	ASSERT_EQ(-1, landlock_restrict_self(ruleset_fd, 0));
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| 	ASSERT_EQ(EPERM, errno);
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| 
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| 	ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
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| 
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| 	/* Checks invalid flags. */
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| 	ASSERT_EQ(-1, landlock_restrict_self(-1, -1));
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| 	ASSERT_EQ(EINVAL, errno);
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| 
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| 	/* Checks invalid ruleset FD. */
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| 	ASSERT_EQ(-1, landlock_restrict_self(-1, 0));
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| 	ASSERT_EQ(EBADF, errno);
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| 
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| 	/* Checks valid call. */
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| 	ASSERT_EQ(0, landlock_restrict_self(ruleset_fd, 0));
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| 	ASSERT_EQ(0, close(ruleset_fd));
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| }
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| 
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| TEST(ruleset_fd_io)
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| {
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| 	struct landlock_ruleset_attr ruleset_attr = {
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| 		.handled_access_fs = LANDLOCK_ACCESS_FS_READ_FILE,
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| 	};
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| 	int ruleset_fd;
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| 	char buf;
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| 
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| 	drop_caps(_metadata);
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| 	ruleset_fd =
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| 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
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| 	ASSERT_LE(0, ruleset_fd);
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| 
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| 	ASSERT_EQ(-1, write(ruleset_fd, ".", 1));
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| 	ASSERT_EQ(EINVAL, errno);
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| 	ASSERT_EQ(-1, read(ruleset_fd, &buf, 1));
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| 	ASSERT_EQ(EINVAL, errno);
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| 
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| 	ASSERT_EQ(0, close(ruleset_fd));
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| }
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| 
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| /* Tests enforcement of a ruleset FD transferred through a UNIX socket. */
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| TEST(ruleset_fd_transfer)
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| {
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| 	struct landlock_ruleset_attr ruleset_attr = {
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| 		.handled_access_fs = LANDLOCK_ACCESS_FS_READ_DIR,
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| 	};
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| 	struct landlock_path_beneath_attr path_beneath_attr = {
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| 		.allowed_access = LANDLOCK_ACCESS_FS_READ_DIR,
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| 	};
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| 	int ruleset_fd_tx, dir_fd;
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| 	union {
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| 		/* Aligned ancillary data buffer. */
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| 		char buf[CMSG_SPACE(sizeof(ruleset_fd_tx))];
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| 		struct cmsghdr _align;
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| 	} cmsg_tx = {};
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| 	char data_tx = '.';
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| 	struct iovec io = {
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| 		.iov_base = &data_tx,
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| 		.iov_len = sizeof(data_tx),
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| 	};
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| 	struct msghdr msg = {
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| 		.msg_iov = &io,
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| 		.msg_iovlen = 1,
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| 		.msg_control = &cmsg_tx.buf,
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| 		.msg_controllen = sizeof(cmsg_tx.buf),
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| 	};
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| 	struct cmsghdr *cmsg;
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| 	int socket_fds[2];
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| 	pid_t child;
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| 	int status;
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| 
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| 	drop_caps(_metadata);
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| 
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| 	/* Creates a test ruleset with a simple rule. */
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| 	ruleset_fd_tx =
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| 		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
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| 	ASSERT_LE(0, ruleset_fd_tx);
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| 	path_beneath_attr.parent_fd =
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| 		open("/tmp", O_PATH | O_NOFOLLOW | O_DIRECTORY | O_CLOEXEC);
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| 	ASSERT_LE(0, path_beneath_attr.parent_fd);
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| 	ASSERT_EQ(0,
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| 		  landlock_add_rule(ruleset_fd_tx, LANDLOCK_RULE_PATH_BENEATH,
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| 				    &path_beneath_attr, 0));
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| 	ASSERT_EQ(0, close(path_beneath_attr.parent_fd));
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| 
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| 	cmsg = CMSG_FIRSTHDR(&msg);
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| 	ASSERT_NE(NULL, cmsg);
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| 	cmsg->cmsg_len = CMSG_LEN(sizeof(ruleset_fd_tx));
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| 	cmsg->cmsg_level = SOL_SOCKET;
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| 	cmsg->cmsg_type = SCM_RIGHTS;
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| 	memcpy(CMSG_DATA(cmsg), &ruleset_fd_tx, sizeof(ruleset_fd_tx));
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| 
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| 	/* Sends the ruleset FD over a socketpair and then close it. */
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| 	ASSERT_EQ(0, socketpair(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0,
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| 				socket_fds));
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| 	ASSERT_EQ(sizeof(data_tx), sendmsg(socket_fds[0], &msg, 0));
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| 	ASSERT_EQ(0, close(socket_fds[0]));
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| 	ASSERT_EQ(0, close(ruleset_fd_tx));
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| 
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| 	child = fork();
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| 	ASSERT_LE(0, child);
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| 	if (child == 0) {
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| 		int ruleset_fd_rx;
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| 
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| 		*(char *)msg.msg_iov->iov_base = '\0';
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| 		ASSERT_EQ(sizeof(data_tx),
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| 			  recvmsg(socket_fds[1], &msg, MSG_CMSG_CLOEXEC));
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| 		ASSERT_EQ('.', *(char *)msg.msg_iov->iov_base);
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| 		ASSERT_EQ(0, close(socket_fds[1]));
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| 		cmsg = CMSG_FIRSTHDR(&msg);
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| 		ASSERT_EQ(cmsg->cmsg_len, CMSG_LEN(sizeof(ruleset_fd_tx)));
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| 		memcpy(&ruleset_fd_rx, CMSG_DATA(cmsg), sizeof(ruleset_fd_tx));
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| 
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| 		/* Enforces the received ruleset on the child. */
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| 		ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0));
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| 		ASSERT_EQ(0, landlock_restrict_self(ruleset_fd_rx, 0));
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| 		ASSERT_EQ(0, close(ruleset_fd_rx));
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| 
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| 		/* Checks that the ruleset enforcement. */
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| 		ASSERT_EQ(-1, open("/", O_RDONLY | O_DIRECTORY | O_CLOEXEC));
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| 		ASSERT_EQ(EACCES, errno);
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| 		dir_fd = open("/tmp", O_RDONLY | O_DIRECTORY | O_CLOEXEC);
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| 		ASSERT_LE(0, dir_fd);
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| 		ASSERT_EQ(0, close(dir_fd));
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| 		_exit(_metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE);
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| 		return;
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| 	}
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| 
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| 	ASSERT_EQ(0, close(socket_fds[1]));
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| 
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| 	/* Checks that the parent is unrestricted. */
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| 	dir_fd = open("/", O_RDONLY | O_DIRECTORY | O_CLOEXEC);
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| 	ASSERT_LE(0, dir_fd);
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| 	ASSERT_EQ(0, close(dir_fd));
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| 	dir_fd = open("/tmp", O_RDONLY | O_DIRECTORY | O_CLOEXEC);
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| 	ASSERT_LE(0, dir_fd);
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| 	ASSERT_EQ(0, close(dir_fd));
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| 
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| 	ASSERT_EQ(child, waitpid(child, &status, 0));
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| 	ASSERT_EQ(1, WIFEXITED(status));
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| 	ASSERT_EQ(EXIT_SUCCESS, WEXITSTATUS(status));
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| }
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| 
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| TEST_HARNESS_MAIN
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