Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

5 files changed, 581 insertions, 0 deletions

diff --git a/tools/testing/selftests/safesetid/.gitignore b/tools/testing/selftests/safesetid/.gitignore
new file mode 100644
index 000000000..25d3db172
--- /dev/null
+++ b/tools/testing/selftests/safesetid/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+safesetid-test
diff --git a/tools/testing/selftests/safesetid/Makefile b/tools/testing/selftests/safesetid/Makefile
new file mode 100644
index 000000000..e815bbf2d
--- /dev/null
+++ b/tools/testing/selftests/safesetid/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0
+# Makefile for SafeSetID selftest.
+CFLAGS = -Wall -O2
+LDLIBS = -lcap
+
+TEST_PROGS := safesetid-test.sh
+TEST_GEN_FILES := safesetid-test
+
+include ../lib.mk
diff --git a/tools/testing/selftests/safesetid/config b/tools/testing/selftests/safesetid/config
new file mode 100644
index 000000000..9d44e5c2e
--- /dev/null
+++ b/tools/testing/selftests/safesetid/config
@@ -0,0 +1,2 @@
+CONFIG_SECURITY=y
+CONFIG_SECURITYFS=y
diff --git a/tools/testing/selftests/safesetid/safesetid-test.c b/tools/testing/selftests/safesetid/safesetid-test.c
new file mode 100644
index 000000000..eb9bf0aee
--- /dev/null
+++ b/tools/testing/selftests/safesetid/safesetid-test.c
@@ -0,0 +1,542 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <errno.h>
+#include <pwd.h>
+#include <grp.h>
+#include <string.h>
+#include <syscall.h>
+#include <sys/capability.h>
+#include <sys/types.h>
+#include <sys/mount.h>
+#include <sys/prctl.h>
+#include <sys/wait.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stdarg.h>
+
+/*
+ * NOTES about this test:
+ * - requries libcap-dev to be installed on test system
+ * - requires securityfs to me mounted at /sys/kernel/security, e.g.:
+ * mount -n -t securityfs -o nodev,noexec,nosuid securityfs /sys/kernel/security
+ * - needs CONFIG_SECURITYFS and CONFIG_SAFESETID to be enabled
+ */
+
+#ifndef CLONE_NEWUSER
+# define CLONE_NEWUSER 0x10000000
+#endif
+
+#define ROOT_UGID 0
+#define RESTRICTED_PARENT_UGID 1
+#define ALLOWED_CHILD1_UGID 2
+#define ALLOWED_CHILD2_UGID 3
+#define NO_POLICY_UGID 4
+
+#define UGID_POLICY_STRING "1:2\n1:3\n2:2\n3:3\n"
+
+char* add_uid_whitelist_policy_file = "/sys/kernel/security/safesetid/uid_allowlist_policy";
+char* add_gid_whitelist_policy_file = "/sys/kernel/security/safesetid/gid_allowlist_policy";
+
+static void die(char *fmt, ...)
+{
+	va_list ap;
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+	exit(EXIT_FAILURE);
+}
+
+static bool vmaybe_write_file(bool enoent_ok, char *filename, char *fmt, va_list ap)
+{
+	char buf[4096];
+	int fd;
+	ssize_t written;
+	int buf_len;
+
+	buf_len = vsnprintf(buf, sizeof(buf), fmt, ap);
+	if (buf_len < 0) {
+		printf("vsnprintf failed: %s\n",
+		    strerror(errno));
+		return false;
+	}
+	if (buf_len >= sizeof(buf)) {
+		printf("vsnprintf output truncated\n");
+		return false;
+	}
+
+	fd = open(filename, O_WRONLY);
+	if (fd < 0) {
+		if ((errno == ENOENT) && enoent_ok)
+			return true;
+		return false;
+	}
+	written = write(fd, buf, buf_len);
+	if (written != buf_len) {
+		if (written >= 0) {
+			printf("short write to %s\n", filename);
+			return false;
+		} else {
+			printf("write to %s failed: %s\n",
+				filename, strerror(errno));
+			return false;
+		}
+	}
+	if (close(fd) != 0) {
+		printf("close of %s failed: %s\n",
+			filename, strerror(errno));
+		return false;
+	}
+	return true;
+}
+
+static bool write_file(char *filename, char *fmt, ...)
+{
+	va_list ap;
+	bool ret;
+
+	va_start(ap, fmt);
+	ret = vmaybe_write_file(false, filename, fmt, ap);
+	va_end(ap);
+
+	return ret;
+}
+
+static void ensure_user_exists(uid_t uid)
+{
+	struct passwd p;
+
+	FILE *fd;
+	char name_str[10];
+
+	if (getpwuid(uid) == NULL) {
+		memset(&p,0x00,sizeof(p));
+		fd=fopen("/etc/passwd","a");
+		if (fd == NULL)
+			die("couldn't open file\n");
+		if (fseek(fd, 0, SEEK_END))
+			die("couldn't fseek\n");
+		snprintf(name_str, 10, "user %d", uid);
+		p.pw_name=name_str;
+		p.pw_uid=uid;
+		p.pw_gid=uid;
+		p.pw_gecos="Test account";
+		p.pw_dir="/dev/null";
+		p.pw_shell="/bin/false";
+		int value = putpwent(&p,fd);
+		if (value != 0)
+			die("putpwent failed\n");
+		if (fclose(fd))
+			die("fclose failed\n");
+	}
+}
+
+static void ensure_group_exists(gid_t gid)
+{
+	struct group g;
+
+	FILE *fd;
+	char name_str[10];
+
+	if (getgrgid(gid) == NULL) {
+		memset(&g,0x00,sizeof(g));
+		fd=fopen("/etc/group","a");
+		if (fd == NULL)
+			die("couldn't open group file\n");
+		if (fseek(fd, 0, SEEK_END))
+			die("couldn't fseek group file\n");
+		snprintf(name_str, 10, "group %d", gid);
+		g.gr_name=name_str;
+		g.gr_gid=gid;
+		g.gr_passwd=NULL;
+		g.gr_mem=NULL;
+		int value = putgrent(&g,fd);
+		if (value != 0)
+			die("putgrent failed\n");
+		if (fclose(fd))
+			die("fclose failed\n");
+	}
+}
+
+static void ensure_securityfs_mounted(void)
+{
+	int fd = open(add_uid_whitelist_policy_file, O_WRONLY);
+	if (fd < 0) {
+		if (errno == ENOENT) {
+			// Need to mount securityfs
+			if (mount("securityfs", "/sys/kernel/security",
+						"securityfs", 0, NULL) < 0)
+				die("mounting securityfs failed\n");
+		} else {
+			die("couldn't find securityfs for unknown reason\n");
+		}
+	} else {
+		if (close(fd) != 0) {
+			die("close of %s failed: %s\n",
+				add_uid_whitelist_policy_file, strerror(errno));
+		}
+	}
+}
+
+static void write_uid_policies()
+{
+	static char *policy_str = UGID_POLICY_STRING;
+	ssize_t written;
+	int fd;
+
+	fd = open(add_uid_whitelist_policy_file, O_WRONLY);
+	if (fd < 0)
+		die("can't open add_uid_whitelist_policy file\n");
+	written = write(fd, policy_str, strlen(policy_str));
+	if (written != strlen(policy_str)) {
+		if (written >= 0) {
+			die("short write to %s\n", add_uid_whitelist_policy_file);
+		} else {
+			die("write to %s failed: %s\n",
+				add_uid_whitelist_policy_file, strerror(errno));
+		}
+	}
+	if (close(fd) != 0) {
+		die("close of %s failed: %s\n",
+			add_uid_whitelist_policy_file, strerror(errno));
+	}
+}
+
+static void write_gid_policies()
+{
+	static char *policy_str = UGID_POLICY_STRING;
+	ssize_t written;
+	int fd;
+
+	fd = open(add_gid_whitelist_policy_file, O_WRONLY);
+	if (fd < 0)
+		die("can't open add_gid_whitelist_policy file\n");
+	written = write(fd, policy_str, strlen(policy_str));
+	if (written != strlen(policy_str)) {
+		if (written >= 0) {
+			die("short write to %s\n", add_gid_whitelist_policy_file);
+		} else {
+			die("write to %s failed: %s\n",
+				add_gid_whitelist_policy_file, strerror(errno));
+		}
+	}
+	if (close(fd) != 0) {
+		die("close of %s failed: %s\n",
+			add_gid_whitelist_policy_file, strerror(errno));
+	}
+}
+
+
+static bool test_userns(bool expect_success)
+{
+	uid_t uid;
+	char map_file_name[32];
+	size_t sz = sizeof(map_file_name);
+	pid_t cpid;
+	bool success;
+
+	uid = getuid();
+
+	int clone_flags = CLONE_NEWUSER;
+	cpid = syscall(SYS_clone, clone_flags, NULL);
+	if (cpid == -1) {
+	    printf("clone failed");
+	    return false;
+	}
+
+	if (cpid == 0) {	/* Code executed by child */
+		// Give parent 1 second to write map file
+		sleep(1);
+		exit(EXIT_SUCCESS);
+	} else {		/* Code executed by parent */
+		if(snprintf(map_file_name, sz, "/proc/%d/uid_map", cpid) < 0) {
+			printf("preparing file name string failed");
+			return false;
+		}
+		success = write_file(map_file_name, "0 %d 1", uid);
+		return success == expect_success;
+	}
+
+	printf("should not reach here");
+	return false;
+}
+
+static void test_setuid(uid_t child_uid, bool expect_success)
+{
+	pid_t cpid, w;
+	int wstatus;
+
+	cpid = fork();
+	if (cpid == -1) {
+		die("fork\n");
+	}
+
+	if (cpid == 0) {	    /* Code executed by child */
+		if (setuid(child_uid) < 0)
+			exit(EXIT_FAILURE);
+		if (getuid() == child_uid)
+			exit(EXIT_SUCCESS);
+		else
+			exit(EXIT_FAILURE);
+	} else {		 /* Code executed by parent */
+		do {
+			w = waitpid(cpid, &wstatus, WUNTRACED | WCONTINUED);
+			if (w == -1) {
+				die("waitpid\n");
+			}
+
+			if (WIFEXITED(wstatus)) {
+				if (WEXITSTATUS(wstatus) == EXIT_SUCCESS) {
+					if (expect_success) {
+						return;
+					} else {
+						die("unexpected success\n");
+					}
+				} else {
+					if (expect_success) {
+						die("unexpected failure\n");
+					} else {
+						return;
+					}
+				}
+			} else if (WIFSIGNALED(wstatus)) {
+				if (WTERMSIG(wstatus) == 9) {
+					if (expect_success)
+						die("killed unexpectedly\n");
+					else
+						return;
+				} else {
+					die("unexpected signal: %d\n", wstatus);
+				}
+			} else {
+				die("unexpected status: %d\n", wstatus);
+			}
+		} while (!WIFEXITED(wstatus) && !WIFSIGNALED(wstatus));
+	}
+
+	die("should not reach here\n");
+}
+
+static void test_setgid(gid_t child_gid, bool expect_success)
+{
+	pid_t cpid, w;
+	int wstatus;
+
+	cpid = fork();
+	if (cpid == -1) {
+		die("fork\n");
+	}
+
+	if (cpid == 0) {	    /* Code executed by child */
+		if (setgid(child_gid) < 0)
+			exit(EXIT_FAILURE);
+		if (getgid() == child_gid)
+			exit(EXIT_SUCCESS);
+		else
+			exit(EXIT_FAILURE);
+	} else {		 /* Code executed by parent */
+		do {
+			w = waitpid(cpid, &wstatus, WUNTRACED | WCONTINUED);
+			if (w == -1) {
+				die("waitpid\n");
+			}
+
+			if (WIFEXITED(wstatus)) {
+				if (WEXITSTATUS(wstatus) == EXIT_SUCCESS) {
+					if (expect_success) {
+						return;
+					} else {
+						die("unexpected success\n");
+					}
+				} else {
+					if (expect_success) {
+						die("unexpected failure\n");
+					} else {
+						return;
+					}
+				}
+			} else if (WIFSIGNALED(wstatus)) {
+				if (WTERMSIG(wstatus) == 9) {
+					if (expect_success)
+						die("killed unexpectedly\n");
+					else
+						return;
+				} else {
+					die("unexpected signal: %d\n", wstatus);
+				}
+			} else {
+				die("unexpected status: %d\n", wstatus);
+			}
+		} while (!WIFEXITED(wstatus) && !WIFSIGNALED(wstatus));
+	}
+
+	die("should not reach here\n");
+}
+
+static void test_setgroups(gid_t* child_groups, size_t len, bool expect_success)
+{
+	pid_t cpid, w;
+	int wstatus;
+	gid_t groupset[len];
+	int i, j;
+
+	cpid = fork();
+	if (cpid == -1) {
+		die("fork\n");
+	}
+
+	if (cpid == 0) {	    /* Code executed by child */
+		if (setgroups(len, child_groups) != 0)
+			exit(EXIT_FAILURE);
+		if (getgroups(len, groupset) != len)
+			exit(EXIT_FAILURE);
+		for (i = 0; i < len; i++) {
+			for (j = 0; j < len; j++) {
+				if (child_groups[i] == groupset[j])
+					break;
+				if (j == len - 1)
+					exit(EXIT_FAILURE);
+			}
+		}
+		exit(EXIT_SUCCESS);
+	} else {		 /* Code executed by parent */
+		do {
+			w = waitpid(cpid, &wstatus, WUNTRACED | WCONTINUED);
+			if (w == -1) {
+				die("waitpid\n");
+			}
+
+			if (WIFEXITED(wstatus)) {
+				if (WEXITSTATUS(wstatus) == EXIT_SUCCESS) {
+					if (expect_success) {
+						return;
+					} else {
+						die("unexpected success\n");
+					}
+				} else {
+					if (expect_success) {
+						die("unexpected failure\n");
+					} else {
+						return;
+					}
+				}
+			} else if (WIFSIGNALED(wstatus)) {
+				if (WTERMSIG(wstatus) == 9) {
+					if (expect_success)
+						die("killed unexpectedly\n");
+					else
+						return;
+				} else {
+					die("unexpected signal: %d\n", wstatus);
+				}
+			} else {
+				die("unexpected status: %d\n", wstatus);
+			}
+		} while (!WIFEXITED(wstatus) && !WIFSIGNALED(wstatus));
+	}
+
+	die("should not reach here\n");
+}
+
+
+static void ensure_users_exist(void)
+{
+	ensure_user_exists(ROOT_UGID);
+	ensure_user_exists(RESTRICTED_PARENT_UGID);
+	ensure_user_exists(ALLOWED_CHILD1_UGID);
+	ensure_user_exists(ALLOWED_CHILD2_UGID);
+	ensure_user_exists(NO_POLICY_UGID);
+}
+
+static void ensure_groups_exist(void)
+{
+	ensure_group_exists(ROOT_UGID);
+	ensure_group_exists(RESTRICTED_PARENT_UGID);
+	ensure_group_exists(ALLOWED_CHILD1_UGID);
+	ensure_group_exists(ALLOWED_CHILD2_UGID);
+	ensure_group_exists(NO_POLICY_UGID);
+}
+
+static void drop_caps(bool setid_retained)
+{
+	cap_value_t cap_values[] = {CAP_SETUID, CAP_SETGID};
+	cap_t caps;
+
+	caps = cap_get_proc();
+	if (setid_retained)
+		cap_set_flag(caps, CAP_EFFECTIVE, 2, cap_values, CAP_SET);
+	else
+		cap_clear(caps);
+	cap_set_proc(caps);
+	cap_free(caps);
+}
+
+int main(int argc, char **argv)
+{
+	ensure_groups_exist();
+	ensure_users_exist();
+	ensure_securityfs_mounted();
+	write_uid_policies();
+	write_gid_policies();
+
+	if (prctl(PR_SET_KEEPCAPS, 1L))
+		die("Error with set keepcaps\n");
+
+	// First test to make sure we can write userns mappings from a non-root
+	// user that doesn't have any restrictions (as long as it has
+	// CAP_SETUID);
+	if (setgid(NO_POLICY_UGID) < 0)
+		die("Error with set gid(%d)\n", NO_POLICY_UGID);
+	if (setuid(NO_POLICY_UGID) < 0)
+		die("Error with set uid(%d)\n", NO_POLICY_UGID);
+	// Take away all but setid caps
+	drop_caps(true);
+	// Need PR_SET_DUMPABLE flag set so we can write /proc/[pid]/uid_map
+	// from non-root parent process.
+	if (prctl(PR_SET_DUMPABLE, 1, 0, 0, 0))
+		die("Error with set dumpable\n");
+	if (!test_userns(true)) {
+		die("test_userns failed when it should work\n");
+	}
+
+	// Now switch to a user/group with restrictions
+	if (setgid(RESTRICTED_PARENT_UGID) < 0)
+		die("Error with set gid(%d)\n", RESTRICTED_PARENT_UGID);
+	if (setuid(RESTRICTED_PARENT_UGID) < 0)
+		die("Error with set uid(%d)\n", RESTRICTED_PARENT_UGID);
+
+	test_setuid(ROOT_UGID, false);
+	test_setuid(ALLOWED_CHILD1_UGID, true);
+	test_setuid(ALLOWED_CHILD2_UGID, true);
+	test_setuid(NO_POLICY_UGID, false);
+
+	test_setgid(ROOT_UGID, false);
+	test_setgid(ALLOWED_CHILD1_UGID, true);
+	test_setgid(ALLOWED_CHILD2_UGID, true);
+	test_setgid(NO_POLICY_UGID, false);
+
+	gid_t allowed_supp_groups[2] = {ALLOWED_CHILD1_UGID, ALLOWED_CHILD2_UGID};
+	gid_t disallowed_supp_groups[2] = {ROOT_UGID, NO_POLICY_UGID};
+	test_setgroups(allowed_supp_groups, 2, true);
+	test_setgroups(disallowed_supp_groups, 2, false);
+
+	if (!test_userns(false)) {
+		die("test_userns worked when it should fail\n");
+	}
+
+	// Now take away all caps
+	drop_caps(false);
+	test_setuid(2, false);
+	test_setuid(3, false);
+	test_setuid(4, false);
+	test_setgid(2, false);
+	test_setgid(3, false);
+	test_setgid(4, false);
+
+	// NOTE: this test doesn't clean up users that were created in
+	// /etc/passwd or flush policies that were added to the LSM.
+	printf("test successful!\n");
+	return EXIT_SUCCESS;
+}
diff --git a/tools/testing/selftests/safesetid/safesetid-test.sh b/tools/testing/selftests/safesetid/safesetid-test.sh
new file mode 100755
index 000000000..e4fdce675
--- /dev/null
+++ b/tools/testing/selftests/safesetid/safesetid-test.sh
@@ -0,0 +1,26 @@
+#!/bin/bash
+
+TCID="safesetid-test.sh"
+errcode=0
+
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+
+check_root()
+{
+	uid=$(id -u)
+	if [ $uid -ne 0 ]; then
+		echo $TCID: must be run as root >&2
+		exit $ksft_skip
+	fi
+}
+
+main_function()
+{
+  check_root
+  ./safesetid-test
+}
+
+main_function
+echo "$TCID: done"
+exit $errcode