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().
  ...

3 files changed, 504 insertions, 0 deletions

diff --git a/tools/testing/selftests/uevent/Makefile b/tools/testing/selftests/uevent/Makefile
new file mode 100644
index 000000000..f7baa9aa2
--- /dev/null
+++ b/tools/testing/selftests/uevent/Makefile
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0
+all:
+
+include ../lib.mk
+
+.PHONY: all clean
+
+BINARIES := uevent_filtering
+CFLAGS += -Wl,-no-as-needed -Wall
+
+uevent_filtering: uevent_filtering.c ../kselftest.h ../kselftest_harness.h
+	$(CC) $(CFLAGS) $< -o $@
+
+TEST_PROGS += $(BINARIES)
+EXTRA_CLEAN := $(BINARIES)
+
+all: $(BINARIES)
diff --git a/tools/testing/selftests/uevent/config b/tools/testing/selftests/uevent/config
new file mode 100644
index 000000000..1038f4515
--- /dev/null
+++ b/tools/testing/selftests/uevent/config
@@ -0,0 +1,2 @@
+CONFIG_USER_NS=y
+CONFIG_NET=y
diff --git a/tools/testing/selftests/uevent/uevent_filtering.c b/tools/testing/selftests/uevent/uevent_filtering.c
new file mode 100644
index 000000000..5cebfb356
--- /dev/null
+++ b/tools/testing/selftests/uevent/uevent_filtering.c
@@ -0,0 +1,485 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/netlink.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/prctl.h>
+#include <sys/socket.h>
+#include <sched.h>
+#include <sys/eventfd.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "../kselftest_harness.h"
+
+#define __DEV_FULL "/sys/devices/virtual/mem/full/uevent"
+#define __UEVENT_BUFFER_SIZE (2048 * 2)
+#define __UEVENT_HEADER "add@/devices/virtual/mem/full"
+#define __UEVENT_HEADER_LEN sizeof("add@/devices/virtual/mem/full")
+#define __UEVENT_LISTEN_ALL -1
+
+ssize_t read_nointr(int fd, void *buf, size_t count)
+{
+	ssize_t ret;
+
+again:
+	ret = read(fd, buf, count);
+	if (ret < 0 && errno == EINTR)
+		goto again;
+
+	return ret;
+}
+
+ssize_t write_nointr(int fd, const void *buf, size_t count)
+{
+	ssize_t ret;
+
+again:
+	ret = write(fd, buf, count);
+	if (ret < 0 && errno == EINTR)
+		goto again;
+
+	return ret;
+}
+
+int wait_for_pid(pid_t pid)
+{
+	int status, ret;
+
+again:
+	ret = waitpid(pid, &status, 0);
+	if (ret == -1) {
+		if (errno == EINTR)
+			goto again;
+
+		return -1;
+	}
+
+	if (ret != pid)
+		goto again;
+
+	if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
+		return -1;
+
+	return 0;
+}
+
+static int uevent_listener(unsigned long post_flags, bool expect_uevent,
+			   int sync_fd)
+{
+	int sk_fd, ret;
+	socklen_t sk_addr_len;
+	int fret = -1, rcv_buf_sz = __UEVENT_BUFFER_SIZE;
+	uint64_t sync_add = 1;
+	struct sockaddr_nl sk_addr = { 0 }, rcv_addr = { 0 };
+	char buf[__UEVENT_BUFFER_SIZE] = { 0 };
+	struct iovec iov = { buf, __UEVENT_BUFFER_SIZE };
+	char control[CMSG_SPACE(sizeof(struct ucred))];
+	struct msghdr hdr = {
+		&rcv_addr, sizeof(rcv_addr), &iov, 1,
+		control,   sizeof(control),  0,
+	};
+
+	sk_fd = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC,
+		       NETLINK_KOBJECT_UEVENT);
+	if (sk_fd < 0) {
+		fprintf(stderr, "%s - Failed to open uevent socket\n", strerror(errno));
+		return -1;
+	}
+
+	ret = setsockopt(sk_fd, SOL_SOCKET, SO_RCVBUF, &rcv_buf_sz,
+			 sizeof(rcv_buf_sz));
+	if (ret < 0) {
+		fprintf(stderr, "%s - Failed to set socket options\n", strerror(errno));
+		goto on_error;
+	}
+
+	sk_addr.nl_family = AF_NETLINK;
+	sk_addr.nl_groups = __UEVENT_LISTEN_ALL;
+
+	sk_addr_len = sizeof(sk_addr);
+	ret = bind(sk_fd, (struct sockaddr *)&sk_addr, sk_addr_len);
+	if (ret < 0) {
+		fprintf(stderr, "%s - Failed to bind socket\n", strerror(errno));
+		goto on_error;
+	}
+
+	ret = getsockname(sk_fd, (struct sockaddr *)&sk_addr, &sk_addr_len);
+	if (ret < 0) {
+		fprintf(stderr, "%s - Failed to retrieve socket name\n", strerror(errno));
+		goto on_error;
+	}
+
+	if ((size_t)sk_addr_len != sizeof(sk_addr)) {
+		fprintf(stderr, "Invalid socket address size\n");
+		goto on_error;
+	}
+
+	if (post_flags & CLONE_NEWUSER) {
+		ret = unshare(CLONE_NEWUSER);
+		if (ret < 0) {
+			fprintf(stderr,
+				"%s - Failed to unshare user namespace\n",
+				strerror(errno));
+			goto on_error;
+		}
+	}
+
+	if (post_flags & CLONE_NEWNET) {
+		ret = unshare(CLONE_NEWNET);
+		if (ret < 0) {
+			fprintf(stderr,
+				"%s - Failed to unshare network namespace\n",
+				strerror(errno));
+			goto on_error;
+		}
+	}
+
+	ret = write_nointr(sync_fd, &sync_add, sizeof(sync_add));
+	close(sync_fd);
+	if (ret != sizeof(sync_add)) {
+		fprintf(stderr, "Failed to synchronize with parent process\n");
+		goto on_error;
+	}
+
+	fret = 0;
+	for (;;) {
+		ssize_t r;
+
+		r = recvmsg(sk_fd, &hdr, 0);
+		if (r <= 0) {
+			fprintf(stderr, "%s - Failed to receive uevent\n", strerror(errno));
+			ret = -1;
+			break;
+		}
+
+		/* ignore libudev messages */
+		if (memcmp(buf, "libudev", 8) == 0)
+			continue;
+
+		/* ignore uevents we didn't trigger */
+		if (memcmp(buf, __UEVENT_HEADER, __UEVENT_HEADER_LEN) != 0)
+			continue;
+
+		if (!expect_uevent) {
+			fprintf(stderr, "Received unexpected uevent:\n");
+			ret = -1;
+		}
+
+		if (TH_LOG_ENABLED) {
+			/* If logging is enabled dump the received uevent. */
+			(void)write_nointr(STDERR_FILENO, buf, r);
+			(void)write_nointr(STDERR_FILENO, "\n", 1);
+		}
+
+		break;
+	}
+
+on_error:
+	close(sk_fd);
+
+	return fret;
+}
+
+int trigger_uevent(unsigned int times)
+{
+	int fd, ret;
+	unsigned int i;
+
+	fd = open(__DEV_FULL, O_RDWR | O_CLOEXEC);
+	if (fd < 0) {
+		if (errno != ENOENT)
+			return -EINVAL;
+
+		return -1;
+	}
+
+	for (i = 0; i < times; i++) {
+		ret = write_nointr(fd, "add\n", sizeof("add\n") - 1);
+		if (ret < 0) {
+			fprintf(stderr, "Failed to trigger uevent\n");
+			break;
+		}
+	}
+	close(fd);
+
+	return ret;
+}
+
+int set_death_signal(void)
+{
+	int ret;
+	pid_t ppid;
+
+	ret = prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
+
+	/* Check whether we have been orphaned. */
+	ppid = getppid();
+	if (ppid == 1) {
+		pid_t self;
+
+		self = getpid();
+		ret = kill(self, SIGKILL);
+	}
+
+	if (ret < 0)
+		return -1;
+
+	return 0;
+}
+
+static int do_test(unsigned long pre_flags, unsigned long post_flags,
+		   bool expect_uevent, int sync_fd)
+{
+	int ret;
+	uint64_t wait_val;
+	pid_t pid;
+	sigset_t mask;
+	sigset_t orig_mask;
+	struct timespec timeout;
+
+	sigemptyset(&mask);
+	sigaddset(&mask, SIGCHLD);
+
+	ret = sigprocmask(SIG_BLOCK, &mask, &orig_mask);
+	if (ret < 0) {
+		fprintf(stderr, "%s- Failed to block SIGCHLD\n", strerror(errno));
+		return -1;
+	}
+
+	pid = fork();
+	if (pid < 0) {
+		fprintf(stderr, "%s - Failed to fork() new process\n", strerror(errno));
+		return -1;
+	}
+
+	if (pid == 0) {
+		/* Make sure that we go away when our parent dies. */
+		ret = set_death_signal();
+		if (ret < 0) {
+			fprintf(stderr, "Failed to set PR_SET_PDEATHSIG to SIGKILL\n");
+			_exit(EXIT_FAILURE);
+		}
+
+		if (pre_flags & CLONE_NEWUSER) {
+			ret = unshare(CLONE_NEWUSER);
+			if (ret < 0) {
+				fprintf(stderr,
+					"%s - Failed to unshare user namespace\n",
+					strerror(errno));
+				_exit(EXIT_FAILURE);
+			}
+		}
+
+		if (pre_flags & CLONE_NEWNET) {
+			ret = unshare(CLONE_NEWNET);
+			if (ret < 0) {
+				fprintf(stderr,
+					"%s - Failed to unshare network namespace\n",
+					strerror(errno));
+				_exit(EXIT_FAILURE);
+			}
+		}
+
+		if (uevent_listener(post_flags, expect_uevent, sync_fd) < 0)
+			_exit(EXIT_FAILURE);
+
+		_exit(EXIT_SUCCESS);
+	}
+
+	ret = read_nointr(sync_fd, &wait_val, sizeof(wait_val));
+	if (ret != sizeof(wait_val)) {
+		fprintf(stderr, "Failed to synchronize with child process\n");
+		_exit(EXIT_FAILURE);
+	}
+
+	/* Trigger 10 uevents to account for the case where the kernel might
+	 * drop some.
+	 */
+	ret = trigger_uevent(10);
+	if (ret < 0)
+		fprintf(stderr, "Failed triggering uevents\n");
+
+	/* Wait for 2 seconds before considering this failed. This should be
+	 * plenty of time for the kernel to deliver the uevent even under heavy
+	 * load.
+	 */
+	timeout.tv_sec = 2;
+	timeout.tv_nsec = 0;
+
+again:
+	ret = sigtimedwait(&mask, NULL, &timeout);
+	if (ret < 0) {
+		if (errno == EINTR)
+			goto again;
+
+		if (!expect_uevent)
+			ret = kill(pid, SIGTERM); /* success */
+		else
+			ret = kill(pid, SIGUSR1); /* error */
+		if (ret < 0)
+			return -1;
+	}
+
+	ret = wait_for_pid(pid);
+	if (ret < 0)
+		return -1;
+
+	return ret;
+}
+
+static void signal_handler(int sig)
+{
+	if (sig == SIGTERM)
+		_exit(EXIT_SUCCESS);
+
+	_exit(EXIT_FAILURE);
+}
+
+TEST(uevent_filtering)
+{
+	int ret, sync_fd;
+	struct sigaction act;
+
+	if (geteuid()) {
+		TH_LOG("Uevent filtering tests require root privileges. Skipping test");
+		_exit(KSFT_SKIP);
+	}
+
+	ret = access(__DEV_FULL, F_OK);
+	EXPECT_EQ(0, ret) {
+		if (errno == ENOENT) {
+			TH_LOG(__DEV_FULL " does not exist. Skipping test");
+			_exit(KSFT_SKIP);
+		}
+
+		_exit(KSFT_FAIL);
+	}
+
+	act.sa_handler = signal_handler;
+	act.sa_flags = 0;
+	sigemptyset(&act.sa_mask);
+
+	ret = sigaction(SIGTERM, &act, NULL);
+	ASSERT_EQ(0, ret);
+
+	sync_fd = eventfd(0, EFD_CLOEXEC);
+	ASSERT_GE(sync_fd, 0);
+
+	/*
+	 * Setup:
+	 * - Open uevent listening socket in initial network namespace owned by
+	 *   initial user namespace.
+	 * - Trigger uevent in initial network namespace owned by initial user
+	 *   namespace.
+	 * Expected Result:
+	 * - uevent listening socket receives uevent
+	 */
+	ret = do_test(0, 0, true, sync_fd);
+	ASSERT_EQ(0, ret) {
+		goto do_cleanup;
+	}
+
+	/*
+	 * Setup:
+	 * - Open uevent listening socket in non-initial network namespace
+	 *   owned by initial user namespace.
+	 * - Trigger uevent in initial network namespace owned by initial user
+	 *   namespace.
+	 * Expected Result:
+	 * - uevent listening socket receives uevent
+	 */
+	ret = do_test(CLONE_NEWNET, 0, true, sync_fd);
+	ASSERT_EQ(0, ret) {
+		goto do_cleanup;
+	}
+
+	/*
+	 * Setup:
+	 * - unshare user namespace
+	 * - Open uevent listening socket in initial network namespace
+	 *   owned by initial user namespace.
+	 * - Trigger uevent in initial network namespace owned by initial user
+	 *   namespace.
+	 * Expected Result:
+	 * - uevent listening socket receives uevent
+	 */
+	ret = do_test(CLONE_NEWUSER, 0, true, sync_fd);
+	ASSERT_EQ(0, ret) {
+		goto do_cleanup;
+	}
+
+	/*
+	 * Setup:
+	 * - Open uevent listening socket in non-initial network namespace
+	 *   owned by non-initial user namespace.
+	 * - Trigger uevent in initial network namespace owned by initial user
+	 *   namespace.
+	 * Expected Result:
+	 * - uevent listening socket receives no uevent
+	 */
+	ret = do_test(CLONE_NEWUSER | CLONE_NEWNET, 0, false, sync_fd);
+	ASSERT_EQ(0, ret) {
+		goto do_cleanup;
+	}
+
+	/*
+	 * Setup:
+	 * - Open uevent listening socket in initial network namespace
+	 *   owned by initial user namespace.
+	 * - unshare network namespace
+	 * - Trigger uevent in initial network namespace owned by initial user
+	 *   namespace.
+	 * Expected Result:
+	 * - uevent listening socket receives uevent
+	 */
+	ret = do_test(0, CLONE_NEWNET, true, sync_fd);
+	ASSERT_EQ(0, ret) {
+		goto do_cleanup;
+	}
+
+	/*
+	 * Setup:
+	 * - Open uevent listening socket in initial network namespace
+	 *   owned by initial user namespace.
+	 * - unshare user namespace
+	 * - Trigger uevent in initial network namespace owned by initial user
+	 *   namespace.
+	 * Expected Result:
+	 * - uevent listening socket receives uevent
+	 */
+	ret = do_test(0, CLONE_NEWUSER, true, sync_fd);
+	ASSERT_EQ(0, ret) {
+		goto do_cleanup;
+	}
+
+	/*
+	 * Setup:
+	 * - Open uevent listening socket in initial network namespace
+	 *   owned by initial user namespace.
+	 * - unshare user namespace
+	 * - unshare network namespace
+	 * - Trigger uevent in initial network namespace owned by initial user
+	 *   namespace.
+	 * Expected Result:
+	 * - uevent listening socket receives uevent
+	 */
+	ret = do_test(0, CLONE_NEWUSER | CLONE_NEWNET, true, sync_fd);
+	ASSERT_EQ(0, ret) {
+		goto do_cleanup;
+	}
+
+do_cleanup:
+	close(sync_fd);
+}
+
+TEST_HARNESS_MAIN