treewide: refresh kmalloc_obj() conversionsgrafted

This is another run of the Coccinelle script for converting kmalloc()
family of allocations to kmalloc_obj() via the existing rules in
scripts/coccinelle/api/kmalloc_objs.cocci

This catches both the set of kmalloc() uses added since the first
kmalloc_obj() conversions in v7.0 and adds a large group missed in the
first pass due to Coccinelle not interacting well with the cleanup.h
scoped_...() family of macros[1]. I worked around this with spatch's
"--macro-file" argument to a file with all the scoped_...() macros mapped
to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control
flow indicator I could find.

Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc,
riscv, and s390 with no new warnings.

Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1]
Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2]
Signed-off-by: Kees Cook <kees+treewide@kernel.org>

3 files changed, 721 insertions, 0 deletions

diff --git a/samples/landlock/.gitignore b/samples/landlock/.gitignore
new file mode 100644
index 000000000..f43668b2d
--- /dev/null
+++ b/samples/landlock/.gitignore
@@ -0,0 +1 @@
+/sandboxer
diff --git a/samples/landlock/Makefile b/samples/landlock/Makefile
new file mode 100644
index 000000000..5d601e51c
--- /dev/null
+++ b/samples/landlock/Makefile
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: BSD-3-Clause
+
+userprogs-always-y := sandboxer
+
+userccflags += -I usr/include
+
+.PHONY: all clean
+
+all:
+	$(MAKE) -C ../.. samples/landlock/
+
+clean:
+	$(MAKE) -C ../.. M=samples/landlock/ clean
diff --git a/samples/landlock/sandboxer.c b/samples/landlock/sandboxer.c
new file mode 100644
index 000000000..030583273
--- /dev/null
+++ b/samples/landlock/sandboxer.c
@@ -0,0 +1,707 @@
+// SPDX-License-Identifier: BSD-3-Clause
+/*
+ * Simple Landlock sandbox manager able to execute a process restricted by
+ * user-defined file system and network access control policies.
+ *
+ * Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net>
+ * Copyright © 2020 ANSSI
+ */
+
+#define _GNU_SOURCE
+#define __SANE_USERSPACE_TYPES__
+#include <arpa/inet.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/landlock.h>
+#include <linux/socket.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/prctl.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+#include <stdbool.h>
+
+#if defined(__GLIBC__)
+#include <linux/prctl.h>
+#endif
+
+#ifndef landlock_create_ruleset
+static inline int
+landlock_create_ruleset(const struct landlock_ruleset_attr *const attr,
+			const size_t size, const __u32 flags)
+{
+	return syscall(__NR_landlock_create_ruleset, attr, size, flags);
+}
+#endif
+
+#ifndef landlock_add_rule
+static inline int landlock_add_rule(const int ruleset_fd,
+				    const enum landlock_rule_type rule_type,
+				    const void *const rule_attr,
+				    const __u32 flags)
+{
+	return syscall(__NR_landlock_add_rule, ruleset_fd, rule_type, rule_attr,
+		       flags);
+}
+#endif
+
+#ifndef landlock_restrict_self
+static inline int landlock_restrict_self(const int ruleset_fd,
+					 const __u32 flags)
+{
+	return syscall(__NR_landlock_restrict_self, ruleset_fd, flags);
+}
+#endif
+
+#define ENV_FS_RO_NAME "LL_FS_RO"
+#define ENV_FS_RW_NAME "LL_FS_RW"
+#define ENV_FS_QUIET_NAME "LL_FS_QUIET"
+#define ENV_TCP_BIND_NAME "LL_TCP_BIND"
+#define ENV_TCP_CONNECT_NAME "LL_TCP_CONNECT"
+#define ENV_NET_QUIET_NAME "LL_NET_QUIET"
+#define ENV_SCOPED_NAME "LL_SCOPED"
+#define ENV_QUIET_ACCESS_NAME "LL_QUIET_ACCESS"
+#define ENV_FORCE_LOG_NAME "LL_FORCE_LOG"
+#define ENV_UDP_BIND_NAME "LL_UDP_BIND"
+#define ENV_UDP_CONNECT_SEND_NAME "LL_UDP_CONNECT_SEND"
+#define ENV_DELIMITER ":"
+
+static int str2num(const char *numstr, __u64 *num_dst)
+{
+	char *endptr = NULL;
+	int err = 0;
+	__u64 num;
+
+	errno = 0;
+	num = strtoull(numstr, &endptr, 10);
+	if (errno != 0)
+		err = errno;
+	/* Was the string empty, or not entirely parsed successfully? */
+	else if ((*numstr == '\0') || (*endptr != '\0'))
+		err = EINVAL;
+	else
+		*num_dst = num;
+
+	return err;
+}
+
+static int parse_path(char *env_path, const char ***const path_list)
+{
+	int i, num_paths = 0;
+
+	if (env_path) {
+		num_paths++;
+		for (i = 0; env_path[i]; i++) {
+			if (env_path[i] == ENV_DELIMITER[0])
+				num_paths++;
+		}
+	}
+	*path_list = malloc(num_paths * sizeof(**path_list));
+	if (!*path_list)
+		return -1;
+
+	for (i = 0; i < num_paths; i++)
+		(*path_list)[i] = strsep(&env_path, ENV_DELIMITER);
+
+	return num_paths;
+}
+
+/* clang-format off */
+
+#define ACCESS_FILE ( \
+	LANDLOCK_ACCESS_FS_EXECUTE | \
+	LANDLOCK_ACCESS_FS_WRITE_FILE | \
+	LANDLOCK_ACCESS_FS_READ_FILE | \
+	LANDLOCK_ACCESS_FS_TRUNCATE | \
+	LANDLOCK_ACCESS_FS_IOCTL_DEV | \
+	LANDLOCK_ACCESS_FS_RESOLVE_UNIX)
+
+/* clang-format on */
+
+static int populate_ruleset_fs(const char *const env_var, const int ruleset_fd,
+			       const __u64 allowed_access, __u32 flags)
+{
+	int num_paths, i, ret = 1;
+	char *env_path_name;
+	const char **path_list = NULL;
+	struct landlock_path_beneath_attr path_beneath = {
+		.parent_fd = -1,
+	};
+
+	env_path_name = getenv(env_var);
+	if (!env_path_name) {
+		/* Prevents users to forget a setting. */
+		fprintf(stderr, "Missing environment variable %s\n", env_var);
+		return 1;
+	}
+	env_path_name = strdup(env_path_name);
+	unsetenv(env_var);
+	num_paths = parse_path(env_path_name, &path_list);
+	if (num_paths < 0) {
+		fprintf(stderr, "Failed to allocate memory\n");
+		goto out_free_name;
+	}
+	if (num_paths == 1 && path_list[0][0] == '\0') {
+		/*
+		 * Allows to not use all possible restrictions (e.g. use
+		 * LL_FS_RO without LL_FS_RW).
+		 */
+		ret = 0;
+		goto out_free_name;
+	}
+
+	for (i = 0; i < num_paths; i++) {
+		struct stat statbuf;
+
+		path_beneath.parent_fd = open(path_list[i], O_PATH | O_CLOEXEC);
+		if (path_beneath.parent_fd < 0) {
+			fprintf(stderr, "Failed to open \"%s\": %s\n",
+				path_list[i], strerror(errno));
+			continue;
+		}
+		if (fstat(path_beneath.parent_fd, &statbuf)) {
+			fprintf(stderr, "Failed to stat \"%s\": %s\n",
+				path_list[i], strerror(errno));
+			close(path_beneath.parent_fd);
+			goto out_free_name;
+		}
+		path_beneath.allowed_access = allowed_access;
+		if (!S_ISDIR(statbuf.st_mode))
+			path_beneath.allowed_access &= ACCESS_FILE;
+		if (landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH,
+				      &path_beneath, flags)) {
+			fprintf(stderr,
+				"Failed to update the ruleset with \"%s\": %s\n",
+				path_list[i], strerror(errno));
+			close(path_beneath.parent_fd);
+			goto out_free_name;
+		}
+		close(path_beneath.parent_fd);
+	}
+	ret = 0;
+
+out_free_name:
+	free(path_list);
+	free(env_path_name);
+	return ret;
+}
+
+static int populate_ruleset_net(const char *const env_var, const int ruleset_fd,
+				const __u64 allowed_access, __u32 flags)
+{
+	int ret = 1;
+	char *env_port_name, *env_port_name_next, *strport;
+	struct landlock_net_port_attr net_port = {
+		.allowed_access = allowed_access,
+	};
+
+	env_port_name = getenv(env_var);
+	if (!env_port_name)
+		return 0;
+	env_port_name = strdup(env_port_name);
+	unsetenv(env_var);
+
+	env_port_name_next = env_port_name;
+	while ((strport = strsep(&env_port_name_next, ENV_DELIMITER))) {
+		__u64 port;
+
+		if (strcmp(strport, "") == 0)
+			continue;
+
+		if (str2num(strport, &port)) {
+			fprintf(stderr, "Failed to parse port at \"%s\"\n",
+				strport);
+			goto out_free_name;
+		}
+		net_port.port = port;
+		if (landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_PORT,
+				      &net_port, flags)) {
+			fprintf(stderr,
+				"Failed to update the ruleset with port \"%llu\": %s\n",
+				net_port.port, strerror(errno));
+			goto out_free_name;
+		}
+	}
+	ret = 0;
+
+out_free_name:
+	free(env_port_name);
+	return ret;
+}
+
+/* Returns true on error, false otherwise. */
+static bool check_ruleset_scope(const char *const env_var,
+				struct landlock_ruleset_attr *ruleset_attr)
+{
+	char *env_type_scope, *env_type_scope_next, *ipc_scoping_name;
+	bool error = false;
+	bool abstract_scoping = false;
+	bool signal_scoping = false;
+
+	/* Scoping is not supported by Landlock ABI */
+	if (!(ruleset_attr->scoped &
+	      (LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET | LANDLOCK_SCOPE_SIGNAL)))
+		goto out_unset;
+
+	env_type_scope = getenv(env_var);
+	/* Scoping is not supported by the user */
+	if (!env_type_scope || strcmp("", env_type_scope) == 0)
+		goto out_unset;
+
+	env_type_scope = strdup(env_type_scope);
+	env_type_scope_next = env_type_scope;
+	while ((ipc_scoping_name =
+			strsep(&env_type_scope_next, ENV_DELIMITER))) {
+		if (strcmp("a", ipc_scoping_name) == 0 && !abstract_scoping) {
+			abstract_scoping = true;
+		} else if (strcmp("s", ipc_scoping_name) == 0 &&
+			   !signal_scoping) {
+			signal_scoping = true;
+		} else {
+			fprintf(stderr, "Unknown or duplicate scope \"%s\"\n",
+				ipc_scoping_name);
+			error = true;
+			goto out_free_name;
+		}
+	}
+
+out_free_name:
+	free(env_type_scope);
+
+out_unset:
+	if (!abstract_scoping)
+		ruleset_attr->scoped &= ~LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET;
+	if (!signal_scoping)
+		ruleset_attr->scoped &= ~LANDLOCK_SCOPE_SIGNAL;
+
+	unsetenv(env_var);
+	return error;
+}
+
+/* clang-format off */
+
+#define ACCESS_FS_ROUGHLY_READ ( \
+	LANDLOCK_ACCESS_FS_EXECUTE | \
+	LANDLOCK_ACCESS_FS_READ_FILE | \
+	LANDLOCK_ACCESS_FS_READ_DIR)
+
+#define ACCESS_FS_ROUGHLY_WRITE ( \
+	LANDLOCK_ACCESS_FS_WRITE_FILE | \
+	LANDLOCK_ACCESS_FS_REMOVE_DIR | \
+	LANDLOCK_ACCESS_FS_REMOVE_FILE | \
+	LANDLOCK_ACCESS_FS_MAKE_CHAR | \
+	LANDLOCK_ACCESS_FS_MAKE_DIR | \
+	LANDLOCK_ACCESS_FS_MAKE_REG | \
+	LANDLOCK_ACCESS_FS_MAKE_SOCK | \
+	LANDLOCK_ACCESS_FS_MAKE_FIFO | \
+	LANDLOCK_ACCESS_FS_MAKE_BLOCK | \
+	LANDLOCK_ACCESS_FS_MAKE_SYM | \
+	LANDLOCK_ACCESS_FS_REFER | \
+	LANDLOCK_ACCESS_FS_TRUNCATE | \
+	LANDLOCK_ACCESS_FS_IOCTL_DEV | \
+	LANDLOCK_ACCESS_FS_RESOLVE_UNIX)
+
+/* clang-format on */
+
+/*
+ * Parses ENV_QUIET_ACCESS_NAME and sets the quiet_access_fs, quiet_access_net
+ * and quiet_scoped masks of @ruleset_attr accordingly.
+ */
+static int add_quiet_access(const char *const env_var,
+			    struct landlock_ruleset_attr *const ruleset_attr)
+{
+	char *env_quiet_access, *env_quiet_access_next, *str_access;
+
+	env_quiet_access = getenv(env_var);
+	if (!env_quiet_access)
+		return 0;
+
+	env_quiet_access = strdup(env_quiet_access);
+	env_quiet_access_next = env_quiet_access;
+	unsetenv(env_var);
+
+	while ((str_access = strsep(&env_quiet_access_next, ENV_DELIMITER))) {
+		if (strcmp(str_access, "") == 0)
+			continue;
+		else if (strcmp(str_access, "all") == 0) {
+			ruleset_attr->quiet_access_fs =
+				ruleset_attr->handled_access_fs;
+			ruleset_attr->quiet_access_net =
+				ruleset_attr->handled_access_net;
+			ruleset_attr->quiet_scoped = ruleset_attr->scoped;
+		} else if (strcmp(str_access, "read") == 0)
+			ruleset_attr->quiet_access_fs |= ACCESS_FS_ROUGHLY_READ;
+		else if (strcmp(str_access, "write") == 0)
+			ruleset_attr->quiet_access_fs |=
+				ACCESS_FS_ROUGHLY_WRITE;
+		else if (strcmp(str_access, "tcp_bind") == 0)
+			ruleset_attr->quiet_access_net |=
+				LANDLOCK_ACCESS_NET_BIND_TCP;
+		else if (strcmp(str_access, "tcp_connect") == 0)
+			ruleset_attr->quiet_access_net |=
+				LANDLOCK_ACCESS_NET_CONNECT_TCP;
+		else if (strcmp(str_access, "udp_bind") == 0)
+			ruleset_attr->quiet_access_net |=
+				LANDLOCK_ACCESS_NET_BIND_UDP;
+		else if (strcmp(str_access, "udp_connect") == 0)
+			ruleset_attr->quiet_access_net |=
+				LANDLOCK_ACCESS_NET_CONNECT_SEND_UDP;
+		else if (strcmp(str_access, "abstract_unix_socket") == 0)
+			ruleset_attr->quiet_scoped |=
+				LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET;
+		else if (strcmp(str_access, "signal") == 0)
+			ruleset_attr->quiet_scoped |= LANDLOCK_SCOPE_SIGNAL;
+		else {
+			fprintf(stderr, "Unknown quiet access \"%s\"\n",
+				str_access);
+			free(env_quiet_access);
+			return -1;
+		}
+	}
+
+	free(env_quiet_access);
+	ruleset_attr->quiet_access_fs &= ruleset_attr->handled_access_fs;
+	ruleset_attr->quiet_access_net &= ruleset_attr->handled_access_net;
+	ruleset_attr->quiet_scoped &= ruleset_attr->scoped;
+	return 0;
+}
+
+#define LANDLOCK_ABI_LAST 11
+
+#define XSTR(s) #s
+#define STR(s) XSTR(s)
+
+/* clang-format off */
+
+static const char help[] =
+	"usage: " ENV_FS_RO_NAME "=\"...\" " ENV_FS_RW_NAME "=\"...\" "
+	"[other environment variables] %1$s <cmd> [args]...\n"
+	"\n"
+	"Execute the given command in a restricted environment.\n"
+	"Multi-valued settings (lists of ports, paths, scopes) are colon-delimited.\n"
+	"\n"
+	"Mandatory settings:\n"
+	"* " ENV_FS_RO_NAME ": paths allowed to be used in a read-only way\n"
+	"* " ENV_FS_RW_NAME ": paths allowed to be used in a read-write way\n"
+	"\n"
+	"Optional settings (when not set, their associated access check "
+	"is always allowed, which is different from an empty string which "
+	"means an empty list):\n"
+	"* " ENV_TCP_BIND_NAME ": ports allowed to bind (server)\n"
+	"* " ENV_TCP_CONNECT_NAME ": ports allowed to connect (client)\n"
+	"* " ENV_UDP_BIND_NAME ": local UDP ports allowed to bind (server: "
+	"prepare to receive on port / client: set as source port)\n"
+	"* " ENV_UDP_CONNECT_SEND_NAME ": remote UDP ports allowed to connect "
+	"or send to (client: use as destination port / server: receive only from it)\n"
+	"(caution: sending requires being able to bind to a local source port)\n"
+	"* " ENV_SCOPED_NAME ": actions denied on the outside of the landlock domain\n"
+	"  - \"a\" to restrict opening abstract unix sockets\n"
+	"  - \"s\" to restrict sending signals\n"
+	"\n"
+	"A sandboxer should not log denied access requests to avoid spamming logs, "
+	"but to test audit we can set " ENV_FORCE_LOG_NAME "=1\n"
+	ENV_FS_QUIET_NAME " and " ENV_NET_QUIET_NAME ", both optional, can then be used "
+	"to make access to some denied paths or network ports not trigger audit logging.\n"
+	ENV_QUIET_ACCESS_NAME " can be used to specify which accesses should be quieted "
+	"(required when " ENV_FS_QUIET_NAME " or " ENV_NET_QUIET_NAME " is set):\n"
+	"  - \"all\" to quiet all of the accesses below\n"
+	"  - \"read\" to quiet all file/dir read accesses\n"
+	"  - \"write\" to quiet all file/dir write accesses\n"
+	"  - \"tcp_bind\" to quiet tcp bind denials\n"
+	"  - \"tcp_connect\" to quiet tcp connect denials\n"
+	"  - \"udp_bind\" to quiet udp bind denials\n"
+	"  - \"udp_connect\" to quiet udp connect / send denials\n"
+	"  - \"abstract_unix_socket\" to quiet abstract unix socket denials\n"
+	"  - \"signal\" to quiet signal denials\n"
+	"\n"
+	"Example:\n"
+	ENV_FS_RO_NAME "=\"${PATH}:/lib:/usr:/proc:/etc:/dev/urandom\" "
+	ENV_FS_RW_NAME "=\"/dev/null:/dev/full:/dev/zero:/dev/pts:/tmp\" "
+	ENV_TCP_BIND_NAME "=\"9418\" "
+	ENV_TCP_CONNECT_NAME "=\"80:443\" "
+	ENV_UDP_CONNECT_SEND_NAME "=\"53\" "
+	ENV_SCOPED_NAME "=\"a:s\" "
+	"%1$s bash -i\n"
+	"\n"
+	"This sandboxer can use Landlock features up to ABI version "
+	STR(LANDLOCK_ABI_LAST) ".\n";
+
+/* clang-format on */
+
+int main(const int argc, char *const argv[], char *const *const envp)
+{
+	const char *cmd_path;
+	char *const *cmd_argv;
+	int ruleset_fd, abi;
+	char *env_port_name, *env_force_log;
+	__u64 access_fs_ro = ACCESS_FS_ROUGHLY_READ,
+	      access_fs_rw = ACCESS_FS_ROUGHLY_READ | ACCESS_FS_ROUGHLY_WRITE;
+
+	struct landlock_ruleset_attr ruleset_attr = {
+		.handled_access_fs = access_fs_rw,
+		.handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP |
+				      LANDLOCK_ACCESS_NET_CONNECT_TCP |
+				      LANDLOCK_ACCESS_NET_BIND_UDP |
+				      LANDLOCK_ACCESS_NET_CONNECT_SEND_UDP,
+		.scoped = LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET |
+			  LANDLOCK_SCOPE_SIGNAL,
+		.quiet_access_fs = 0,
+		.quiet_access_net = 0,
+		.quiet_scoped = 0,
+	};
+	bool quiet_supported = true;
+	int supported_restrict_flags = LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON |
+				       LANDLOCK_RESTRICT_SELF_NO_NEW_PRIVS;
+	int set_restrict_flags = LANDLOCK_RESTRICT_SELF_NO_NEW_PRIVS;
+
+	if (argc < 2) {
+		fprintf(stderr, help, argv[0]);
+		return 1;
+	}
+
+	abi = landlock_create_ruleset(NULL, 0, LANDLOCK_CREATE_RULESET_VERSION);
+	if (abi < 0) {
+		const int err = errno;
+
+		perror("Failed to check Landlock compatibility");
+		switch (err) {
+		case ENOSYS:
+			fprintf(stderr,
+				"Hint: Landlock is not supported by the current kernel. "
+				"To support it, build the kernel with "
+				"CONFIG_SECURITY_LANDLOCK=y and prepend "
+				"\"landlock,\" to the content of CONFIG_LSM.\n");
+			break;
+		case EOPNOTSUPP:
+			fprintf(stderr,
+				"Hint: Landlock is currently disabled. "
+				"It can be enabled in the kernel configuration by "
+				"prepending \"landlock,\" to the content of CONFIG_LSM, "
+				"or at boot time by setting the same content to the "
+				"\"lsm\" kernel parameter.\n");
+			break;
+		}
+		return 1;
+	}
+
+	/* Best-effort security. */
+	switch (abi) {
+	case 1:
+		/*
+		 * Removes LANDLOCK_ACCESS_FS_REFER for ABI < 2
+		 *
+		 * Note: The "refer" operations (file renaming and linking
+		 * across different directories) are always forbidden when using
+		 * Landlock with ABI 1.
+		 *
+		 * If only ABI 1 is available, this sandboxer knowingly forbids
+		 * refer operations.
+		 *
+		 * If a program *needs* to do refer operations after enabling
+		 * Landlock, it can not use Landlock at ABI level 1.  To be
+		 * compatible with different kernel versions, such programs
+		 * should then fall back to not restrict themselves at all if
+		 * the running kernel only supports ABI 1.
+		 */
+		ruleset_attr.handled_access_fs &= ~LANDLOCK_ACCESS_FS_REFER;
+		__attribute__((fallthrough));
+	case 2:
+		/* Removes LANDLOCK_ACCESS_FS_TRUNCATE for ABI < 3 */
+		ruleset_attr.handled_access_fs &= ~LANDLOCK_ACCESS_FS_TRUNCATE;
+		__attribute__((fallthrough));
+	case 3:
+		/* Removes network support for ABI < 4 */
+		ruleset_attr.handled_access_net &=
+			~(LANDLOCK_ACCESS_NET_BIND_TCP |
+			  LANDLOCK_ACCESS_NET_CONNECT_TCP);
+		__attribute__((fallthrough));
+	case 4:
+		/* Removes LANDLOCK_ACCESS_FS_IOCTL_DEV for ABI < 5 */
+		ruleset_attr.handled_access_fs &= ~LANDLOCK_ACCESS_FS_IOCTL_DEV;
+
+		__attribute__((fallthrough));
+	case 5:
+		/* Removes LANDLOCK_SCOPE_* for ABI < 6 */
+		ruleset_attr.scoped &= ~(LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET |
+					 LANDLOCK_SCOPE_SIGNAL);
+		__attribute__((fallthrough));
+	case 6:
+		/* Removes LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON for ABI < 7 */
+		supported_restrict_flags &=
+			~LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON;
+		__attribute__((fallthrough));
+	case 7:
+	case 8:
+		/* Removes LANDLOCK_ACCESS_FS_RESOLVE_UNIX for ABI < 9 */
+		ruleset_attr.handled_access_fs &=
+			~LANDLOCK_ACCESS_FS_RESOLVE_UNIX;
+		__attribute__((fallthrough));
+	case 9:
+		/* Removes UDP support for ABI < 10 */
+		ruleset_attr.handled_access_net &=
+			~(LANDLOCK_ACCESS_NET_BIND_UDP |
+			  LANDLOCK_ACCESS_NET_CONNECT_SEND_UDP);
+		/* Removes quiet flags for ABI < 10 later on. */
+		quiet_supported = false;
+		__attribute__((fallthrough));
+	case 10:
+		/* Removes LANDLOCK_RESTRICT_SELF_NO_NEW_PRIVS for ABI < 11 */
+		supported_restrict_flags &=
+			~LANDLOCK_RESTRICT_SELF_NO_NEW_PRIVS;
+		set_restrict_flags &= ~LANDLOCK_RESTRICT_SELF_NO_NEW_PRIVS;
+
+		/* Must be printed for any ABI < LANDLOCK_ABI_LAST. */
+		fprintf(stderr,
+			"Hint: You should update the running kernel "
+			"to leverage Landlock features "
+			"provided by ABI version %d (instead of %d).\n",
+			LANDLOCK_ABI_LAST, abi);
+		__attribute__((fallthrough));
+	case LANDLOCK_ABI_LAST:
+		break;
+	default:
+		fprintf(stderr,
+			"Hint: You should update this sandboxer "
+			"to leverage Landlock features "
+			"provided by ABI version %d (instead of %d).\n",
+			abi, LANDLOCK_ABI_LAST);
+	}
+	access_fs_ro &= ruleset_attr.handled_access_fs;
+	access_fs_rw &= ruleset_attr.handled_access_fs;
+
+	/* Removes bind access attribute if not supported by a user. */
+	env_port_name = getenv(ENV_TCP_BIND_NAME);
+	if (!env_port_name) {
+		ruleset_attr.handled_access_net &=
+			~LANDLOCK_ACCESS_NET_BIND_TCP;
+	}
+	/* Removes connect access attribute if not supported by a user. */
+	env_port_name = getenv(ENV_TCP_CONNECT_NAME);
+	if (!env_port_name) {
+		ruleset_attr.handled_access_net &=
+			~LANDLOCK_ACCESS_NET_CONNECT_TCP;
+	}
+	/* Removes UDP bind access control if not supported by a user. */
+	env_port_name = getenv(ENV_UDP_BIND_NAME);
+	if (!env_port_name) {
+		ruleset_attr.handled_access_net &=
+			~LANDLOCK_ACCESS_NET_BIND_UDP;
+	}
+	/* Removes UDP connect/send access control if not supported by a user. */
+	env_port_name = getenv(ENV_UDP_CONNECT_SEND_NAME);
+	if (!env_port_name) {
+		ruleset_attr.handled_access_net &=
+			~LANDLOCK_ACCESS_NET_CONNECT_SEND_UDP;
+	}
+
+	if (check_ruleset_scope(ENV_SCOPED_NAME, &ruleset_attr))
+		return 1;
+
+	/* Enables optional logs. */
+	env_force_log = getenv(ENV_FORCE_LOG_NAME);
+	if (env_force_log) {
+		if (strcmp(env_force_log, "1") != 0) {
+			fprintf(stderr, "Unknown value for " ENV_FORCE_LOG_NAME
+					" (only \"1\" is handled)\n");
+			return 1;
+		}
+		if (!(supported_restrict_flags &
+		      LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON)) {
+			fprintf(stderr,
+				"Audit logs not supported by current kernel\n");
+			return 1;
+		}
+		set_restrict_flags |= LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON;
+		unsetenv(ENV_FORCE_LOG_NAME);
+	}
+
+	/* Set the quiet access masks. */
+	if (quiet_supported) {
+		if ((getenv(ENV_FS_QUIET_NAME) || getenv(ENV_NET_QUIET_NAME)) &&
+		    !getenv(ENV_QUIET_ACCESS_NAME)) {
+			fprintf(stderr,
+				"%s must be set (e.g. to \"all\") when %s or %s is used\n",
+				ENV_QUIET_ACCESS_NAME, ENV_FS_QUIET_NAME,
+				ENV_NET_QUIET_NAME);
+			return 1;
+		}
+		if (add_quiet_access(ENV_QUIET_ACCESS_NAME, &ruleset_attr))
+			return 1;
+	} else if (getenv(ENV_FS_QUIET_NAME) || getenv(ENV_NET_QUIET_NAME) ||
+		   getenv(ENV_QUIET_ACCESS_NAME)) {
+		fprintf(stderr,
+			"Quiet flags not supported by current kernel\n");
+		return 1;
+	}
+
+	ruleset_fd =
+		landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0);
+	if (ruleset_fd < 0) {
+		perror("Failed to create a ruleset");
+		return 1;
+	}
+
+	if (populate_ruleset_fs(ENV_FS_RO_NAME, ruleset_fd, access_fs_ro, 0))
+		goto err_close_ruleset;
+	if (populate_ruleset_fs(ENV_FS_RW_NAME, ruleset_fd, access_fs_rw, 0))
+		goto err_close_ruleset;
+
+	/* Don't require this env to be present. */
+	if (quiet_supported && getenv(ENV_FS_QUIET_NAME)) {
+		if (populate_ruleset_fs(ENV_FS_QUIET_NAME, ruleset_fd, 0,
+					LANDLOCK_ADD_RULE_QUIET))
+			goto err_close_ruleset;
+	}
+
+	if (populate_ruleset_net(ENV_TCP_BIND_NAME, ruleset_fd,
+				 LANDLOCK_ACCESS_NET_BIND_TCP, 0)) {
+		goto err_close_ruleset;
+	}
+	if (populate_ruleset_net(ENV_TCP_CONNECT_NAME, ruleset_fd,
+				 LANDLOCK_ACCESS_NET_CONNECT_TCP, 0)) {
+		goto err_close_ruleset;
+	}
+	if (populate_ruleset_net(ENV_UDP_BIND_NAME, ruleset_fd,
+				 LANDLOCK_ACCESS_NET_BIND_UDP, 0)) {
+		goto err_close_ruleset;
+	}
+	if (populate_ruleset_net(ENV_UDP_CONNECT_SEND_NAME, ruleset_fd,
+				 LANDLOCK_ACCESS_NET_CONNECT_SEND_UDP, 0)) {
+		goto err_close_ruleset;
+	}
+
+	if (quiet_supported) {
+		if (populate_ruleset_net(ENV_NET_QUIET_NAME, ruleset_fd, 0,
+					 LANDLOCK_ADD_RULE_QUIET)) {
+			goto err_close_ruleset;
+		}
+	}
+
+	if (!(set_restrict_flags & LANDLOCK_RESTRICT_SELF_NO_NEW_PRIVS) &&
+	    prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
+		perror("Failed to restrict privileges");
+		goto err_close_ruleset;
+	}
+	if (landlock_restrict_self(ruleset_fd, set_restrict_flags)) {
+		perror("Failed to enforce ruleset");
+		goto err_close_ruleset;
+	}
+	close(ruleset_fd);
+
+	cmd_path = argv[1];
+	cmd_argv = argv + 1;
+	fprintf(stderr, "Executing the sandboxed command...\n");
+	execvpe(cmd_path, cmd_argv, envp);
+	fprintf(stderr, "Failed to execute \"%s\": %s\n", cmd_path,
+		strerror(errno));
+	fprintf(stderr, "Hint: access to the binary, the interpreter or "
+			"shared libraries may be denied.\n");
+	return 1;
+
+err_close_ruleset:
+	close(ruleset_fd);
+	return 1;
+}