diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index cdb57e6b9..c494962e4 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -48,9 +48,12 @@ jobs:
           echo "LDFLAGS_SHARED=$(cat release/LDFLAGS)" >> "$GITHUB_ENV"
       - name: Install usbip tools
         if: matrix.os == 'ubuntu-latest'
+        shell: bash
         run: |
           sudo apt-get update
-          sudo apt-get install -y linux-tools-common
+          sudo apt-get install -y linux-tools-common "linux-tools-$(uname -r)"
+          usbip version
+          usbipd --version
       - name: Test (unix)
         if: matrix.os != 'windows-latest'
         run: go test -v -exec sudo -tags "$BUILD_TAGS" -ldflags "$LDFLAGS_SHARED" ./...
diff --git a/service/usbip/client_linux.go b/service/usbip/client_linux.go
index 883bcd8b6..b57dda6d0 100644
--- a/service/usbip/client_linux.go
+++ b/service/usbip/client_linux.go
@@ -795,12 +795,7 @@ func assignMatchedBusIDs(targets []clientTarget, current []string, entries []Dev
 		if busid == "" {
 			continue
 		}
-		keysByBusID[busid] = DeviceKey{
-			BusID:     busid,
-			VendorID:  entries[i].Info.IDVendor,
-			ProductID: entries[i].Info.IDProduct,
-			Serial:    entries[i].Info.SerialString(),
-		}
+		keysByBusID[busid] = entryDeviceKey(entries[i])
 	}
 
 	nextAssigned := make([]string, len(targets))
@@ -846,12 +841,7 @@ func assignMatchedBusIDs(targets []clientTarget, current []string, entries []Dev
 
 func firstMatchingUnclaimedBusID(match option.USBIPDeviceMatch, entries []DeviceEntry, reserved map[string]struct{}) string {
 	for i := range entries {
-		key := DeviceKey{
-			BusID:     entries[i].Info.BusIDString(),
-			VendorID:  entries[i].Info.IDVendor,
-			ProductID: entries[i].Info.IDProduct,
-			Serial:    entries[i].Info.SerialString(),
-		}
+		key := entryDeviceKey(entries[i])
 		if _, claimed := reserved[key.BusID]; claimed {
 			continue
 		}
diff --git a/service/usbip/control_protocol.go b/service/usbip/control_protocol.go
index e30e0b1b8..7bbbe517b 100644
--- a/service/usbip/control_protocol.go
+++ b/service/usbip/control_protocol.go
@@ -293,7 +293,7 @@ func deviceInfoV2FromEntry(entry DeviceEntry, backend string, stableID string, s
 		StableID:           stableID,
 		Backend:            backend,
 		Path:               entry.Info.PathString(),
-		Serial:             entry.Info.SerialString(),
+		Serial:             entrySerial(entry),
 		VendorID:           entry.Info.IDVendor,
 		ProductID:          entry.Info.IDProduct,
 		BCDDevice:          entry.Info.BCDDevice,
@@ -313,7 +313,7 @@ func deviceInfoV2FromEntry(entry DeviceEntry, backend string, stableID string, s
 
 func (d DeviceInfoV2) toDeviceEntry() DeviceEntry {
 	var info DeviceInfoTruncated
-	encodePathField(&info.Path, d.Path, d.Serial)
+	encodePathField(&info.Path, d.Path)
 	copy(info.BusID[:], d.BusID)
 	info.Speed = d.Speed
 	info.IDVendor = d.VendorID
@@ -333,7 +333,7 @@ func (d DeviceInfoV2) toDeviceEntry() DeviceEntry {
 			BInterfaceProtocol: d.Interfaces[i].Protocol,
 		}
 	}
-	return DeviceEntry{Info: info, Interfaces: interfaces}
+	return DeviceEntry{Info: info, Interfaces: interfaces, Serial: d.Serial}
 }
 
 func (d DeviceInfoV2) key() DeviceKey {
diff --git a/service/usbip/darwin_integration_test.go b/service/usbip/darwin_integration_test.go
index bf4af8b03..1120e399c 100644
--- a/service/usbip/darwin_integration_test.go
+++ b/service/usbip/darwin_integration_test.go
@@ -674,7 +674,7 @@ func truncateDarwinFakeDescriptor(data []byte, length int) []byte {
 
 func darwinFakeDeviceEntry() DeviceEntry {
 	var info DeviceInfoTruncated
-	encodePathField(&info.Path, "fake-darwin-usbip", "codex-usbip-fake")
+	encodePathField(&info.Path, "fake-darwin-usbip")
 	copy(info.BusID[:], darwinFakeBusID)
 	info.BusNum = 1
 	info.DevNum = 1
@@ -686,7 +686,8 @@ func darwinFakeDeviceEntry() DeviceEntry {
 	info.BNumConfigurations = 1
 	info.BNumInterfaces = 1
 	return DeviceEntry{
-		Info: info,
+		Info:   info,
+		Serial: "codex-usbip-fake",
 		Interfaces: []DeviceInterface{{
 			BInterfaceClass:    0xff,
 			BInterfaceSubClass: 0x42,
diff --git a/service/usbip/linux_interop_test.go b/service/usbip/linux_interop_test.go
index 96c769e78..93af04301 100644
--- a/service/usbip/linux_interop_test.go
+++ b/service/usbip/linux_interop_test.go
@@ -108,12 +108,30 @@ func requireUSBIPTools(t *testing.T) testUSBIPTools {
 	if usbipErr != nil || usbipdErr != nil {
 		t.Skip("usbip and usbipd are required")
 	}
+	requireRunnableUSBIPTool(t, usbipPath, "version")
+	requireRunnableUSBIPTool(t, usbipdPath, "--version")
 	return testUSBIPTools{
 		usbip:  usbipPath,
 		usbipd: usbipdPath,
 	}
 }
 
+func requireRunnableUSBIPTool(t *testing.T, path string, args ...string) {
+	t.Helper()
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+	command := exec.CommandContext(ctx, path, args...)
+	command.Env = os.Environ()
+	output, err := command.CombinedOutput()
+	if ctx.Err() != nil {
+		t.Skipf("%s %s timed out", path, strings.Join(args, " "))
+	}
+	if err != nil {
+		t.Skipf("%s is unavailable: %v\n%s", path, err, strings.TrimSpace(string(output)))
+	}
+}
+
 func currentUDCNames() []string {
 	entries, err := os.ReadDir("/sys/class/udc")
 	if err != nil {
diff --git a/service/usbip/linux_test.go b/service/usbip/linux_test.go
index 701913cab..e9c680ef4 100644
--- a/service/usbip/linux_test.go
+++ b/service/usbip/linux_test.go
@@ -600,9 +600,9 @@ func TestAssignMatchedBusIDs(t *testing.T) {
 	first := newTestDevice("1-2", 0x1d6b, 0x0002, "first", SpeedHigh)
 	second := newTestDevice("1-3", 0x1d6b, 0x0002, "second", SpeedHigh)
 	entries := []DeviceEntry{
-		{Info: fixed.toProtocol()},
-		{Info: first.toProtocol()},
-		{Info: second.toProtocol()},
+		fixed.toDeviceEntry(),
+		first.toDeviceEntry(),
+		second.toDeviceEntry(),
 	}
 
 	require.Equal(t, []string{"1-1", "1-3", "1-2"}, assignMatchedBusIDs(
@@ -969,7 +969,7 @@ func TestServerBuildDevListEntriesFiltersUnavailableAndRefreshFailures(t *testin
 	entries := server.buildDevListEntries()
 	require.Len(t, entries, 1)
 	require.Equal(t, "1-1", entries[0].Info.BusIDString())
-	require.Equal(t, "ok", entries[0].Info.SerialString())
+	require.Equal(t, "ok", entries[0].Serial)
 }
 
 func TestServerHandleImportWithOpaqueConnRelay(t *testing.T) {
@@ -2036,7 +2036,7 @@ func TestClientSyncRemoteStateAndResetControlStateRebuildsV2Map(t *testing.T) {
 	defer cancel()
 
 	device := newTestDevice("1-1", 0x1d6b, 0x0002, "serial-1", SpeedHigh)
-	entry := DeviceEntry{Info: device.toProtocol(), Interfaces: device.Interfaces}
+	entry := device.toDeviceEntry()
 	listener, err := net.Listen("tcp", "127.0.0.1:0")
 	require.NoError(t, err)
 	defer listener.Close()
diff --git a/service/usbip/protocol.go b/service/usbip/protocol.go
index a7a4121a1..8fa9b58af 100644
--- a/service/usbip/protocol.go
+++ b/service/usbip/protocol.go
@@ -80,6 +80,7 @@ type DeviceInterface struct {
 type DeviceEntry struct {
 	Info       DeviceInfoTruncated
 	Interfaces []DeviceInterface
+	Serial     string // internal metadata carried by control V2, not OP_REP_* wire data
 }
 
 type ImportExtRequest struct {
@@ -279,12 +280,8 @@ func (d *DeviceInfoTruncated) DevID() uint32 {
 	return (d.BusNum << 16) | (d.DevNum & 0xffff)
 }
 
-func encodePathField(dst *[256]byte, path, serial string) {
+func encodePathField(dst *[256]byte, path string) {
 	copy(dst[:], path)
-	if serial == "" || len(path) >= len(dst)-1 {
-		return
-	}
-	copy(dst[len(path)+1:], "serial="+serial)
 }
 
 func cstring(b []byte) string {
@@ -308,3 +305,19 @@ func trailingCString(b []byte) string {
 	}
 	return ""
 }
+
+func entrySerial(entry DeviceEntry) string {
+	if entry.Serial != "" {
+		return entry.Serial
+	}
+	return entry.Info.SerialString()
+}
+
+func entryDeviceKey(entry DeviceEntry) DeviceKey {
+	return DeviceKey{
+		BusID:     entry.Info.BusIDString(),
+		VendorID:  entry.Info.IDVendor,
+		ProductID: entry.Info.IDProduct,
+		Serial:    entrySerial(entry),
+	}
+}
diff --git a/service/usbip/protocol_test.go b/service/usbip/protocol_test.go
index 875d8f7fd..7b3f3e119 100644
--- a/service/usbip/protocol_test.go
+++ b/service/usbip/protocol_test.go
@@ -247,7 +247,7 @@ func TestOpRepDevListRoundTrip(t *testing.T) {
 	t.Parallel()
 
 	var path [256]byte
-	encodePathField(&path, "/sys/bus/usb/devices/1-2", "serial-1")
+	encodePathField(&path, "/sys/bus/usb/devices/1-2")
 
 	entries := []DeviceEntry{{
 		Info: DeviceInfoTruncated{
@@ -293,13 +293,13 @@ func TestDeviceInfoHelpers(t *testing.T) {
 	t.Parallel()
 
 	var info DeviceInfoTruncated
-	encodePathField(&info.Path, "/sys/bus/usb/devices/1-2", "serial-1")
+	encodePathField(&info.Path, "/sys/bus/usb/devices/1-2")
 	copy(info.BusID[:], "1-2")
 	info.BusNum = 3
 	info.DevNum = 9
 
 	require.Equal(t, "/sys/bus/usb/devices/1-2", info.PathString())
-	require.Equal(t, "serial-1", info.SerialString())
+	require.Empty(t, info.SerialString())
 	require.Equal(t, "1-2", info.BusIDString())
 	require.Equal(t, uint32(0x00030009), info.DevID())
 }
@@ -308,7 +308,7 @@ func TestDeviceInfoV2RoundTrip(t *testing.T) {
 	t.Parallel()
 
 	var path [256]byte
-	encodePathField(&path, "/sys/bus/usb/devices/1-2", "serial-1")
+	encodePathField(&path, "/sys/bus/usb/devices/1-2")
 	entry := DeviceEntry{
 		Info: DeviceInfoTruncated{
 			Path:                path,
@@ -326,6 +326,7 @@ func TestDeviceInfoV2RoundTrip(t *testing.T) {
 			BNumInterfaces:      1,
 		},
 		Interfaces: []DeviceInterface{{BInterfaceClass: 0xff, BInterfaceSubClass: 1, BInterfaceProtocol: 2}},
+		Serial:     "serial-1",
 	}
 	copy(entry.Info.BusID[:], "1-2")
 
@@ -336,18 +337,22 @@ func TestDeviceInfoV2RoundTrip(t *testing.T) {
 	require.Equal(t, DeviceKey{BusID: "1-2", VendorID: 0x1d6b, ProductID: 0x0002, Serial: "serial-1"}, info.key())
 	roundTrip := info.toDeviceEntry()
 	require.Equal(t, "1-2", roundTrip.Info.BusIDString())
-	require.Equal(t, "serial-1", roundTrip.Info.SerialString())
+	require.Equal(t, "serial-1", roundTrip.Serial)
+	require.Empty(t, roundTrip.Info.SerialString())
 	require.Equal(t, uint16(0x1d6b), roundTrip.Info.IDVendor)
 	require.Equal(t, uint16(0x0002), roundTrip.Info.IDProduct)
 	require.Equal(t, entry.Interfaces, roundTrip.Interfaces)
 }
 
-func TestEncodePathFieldSkipsSerialWithoutRoom(t *testing.T) {
+func TestEncodePathFieldZeroPadsPath(t *testing.T) {
 	t.Parallel()
 
 	var info DeviceInfoTruncated
-	encodePathField(&info.Path, strings.Repeat("a", len(info.Path)-1), "serial-1")
+	encodePathField(&info.Path, "/sys/bus/usb/devices/1-2")
 
+	pathLen := len("/sys/bus/usb/devices/1-2")
+	require.Equal(t, byte(0), info.Path[pathLen])
+	require.Equal(t, make([]byte, len(info.Path)-pathLen-1), info.Path[pathLen+1:])
 	require.Empty(t, info.SerialString())
 }
 
diff --git a/service/usbip/server_linux.go b/service/usbip/server_linux.go
index 5ad8a578b..86b24e40d 100644
--- a/service/usbip/server_linux.go
+++ b/service/usbip/server_linux.go
@@ -479,10 +479,7 @@ func (s *ServerService) buildDevListEntries() []DeviceEntry {
 			s.logger.Debug("refresh ", busid, ": ", err)
 			continue
 		}
-		entries = append(entries, DeviceEntry{
-			Info:       d.toProtocol(),
-			Interfaces: d.Interfaces,
-		})
+		entries = append(entries, d.toDeviceEntry())
 	}
 	return entries
 }
@@ -773,7 +770,7 @@ func (s *ServerService) buildDeviceStateV2() []DeviceInfoV2 {
 			state = deviceStateUnavailable
 			reason = statusErr.Error()
 		}
-		entry := DeviceEntry{Info: dev.toProtocol(), Interfaces: dev.Interfaces}
+		entry := dev.toDeviceEntry()
 		devices = append(devices, deviceInfoV2FromEntry(entry, "linux-sysfs", linuxStableID(dev), state, status, reason))
 	}
 	return devices
diff --git a/service/usbip/shared_darwin.go b/service/usbip/shared_darwin.go
index 3466bacf4..4410a43d4 100644
--- a/service/usbip/shared_darwin.go
+++ b/service/usbip/shared_darwin.go
@@ -36,12 +36,7 @@ func assignMatchedBusIDs(targets []clientTarget, current []string, entries []Dev
 		if busid == "" {
 			continue
 		}
-		keysByBusID[busid] = DeviceKey{
-			BusID:     busid,
-			VendorID:  entries[i].Info.IDVendor,
-			ProductID: entries[i].Info.IDProduct,
-			Serial:    entries[i].Info.SerialString(),
-		}
+		keysByBusID[busid] = entryDeviceKey(entries[i])
 	}
 	nextAssigned := make([]string, len(targets))
 	reserved := make(map[string]struct{}, len(targets))
@@ -83,12 +78,7 @@ func assignMatchedBusIDs(targets []clientTarget, current []string, entries []Dev
 
 func firstMatchingUnclaimedBusID(match option.USBIPDeviceMatch, entries []DeviceEntry, reserved map[string]struct{}) string {
 	for i := range entries {
-		key := DeviceKey{
-			BusID:     entries[i].Info.BusIDString(),
-			VendorID:  entries[i].Info.IDVendor,
-			ProductID: entries[i].Info.IDProduct,
-			Serial:    entries[i].Info.SerialString(),
-		}
+		key := entryDeviceKey(entries[i])
 		if _, claimed := reserved[key.BusID]; claimed {
 			continue
 		}
diff --git a/service/usbip/sysfs_linux.go b/service/usbip/sysfs_linux.go
index fec381c5f..4e43749ce 100644
--- a/service/usbip/sysfs_linux.go
+++ b/service/usbip/sysfs_linux.go
@@ -57,7 +57,7 @@ func (d *sysfsDevice) key() DeviceKey {
 
 func (d *sysfsDevice) toProtocol() DeviceInfoTruncated {
 	var info DeviceInfoTruncated
-	encodePathField(&info.Path, d.Path, d.Serial)
+	encodePathField(&info.Path, d.Path)
 	copy(info.BusID[:], d.BusID)
 	info.BusNum = d.BusNum
 	info.DevNum = d.DevNum
@@ -74,6 +74,14 @@ func (d *sysfsDevice) toProtocol() DeviceInfoTruncated {
 	return info
 }
 
+func (d *sysfsDevice) toDeviceEntry() DeviceEntry {
+	return DeviceEntry{
+		Info:       d.toProtocol(),
+		Interfaces: d.Interfaces,
+		Serial:     d.Serial,
+	}
+}
+
 type vhciStatusRecord struct {
 	hub   string
 	port  int
diff --git a/service/usbip/uevent_linux.go b/service/usbip/uevent_linux.go
index 2eaeeb53e..e2d866102 100644
--- a/service/usbip/uevent_linux.go
+++ b/service/usbip/uevent_linux.go
@@ -4,7 +4,6 @@ package usbip
 
 import (
 	"bytes"
-	"os"
 
 	"golang.org/x/sys/unix"
 )
@@ -20,7 +19,6 @@ func newUEventListener() (*ueventListener, error) {
 	}
 	addr := &unix.SockaddrNetlink{
 		Family: unix.AF_NETLINK,
-		Pid:    uint32(os.Getpid()),
 		Groups: 1,
 	}
 	if err := unix.Bind(fd, addr); err != nil {
diff --git a/service/usbip/usbhost_darwin.go b/service/usbip/usbhost_darwin.go
index 518e4f6b2..c54d1c50f 100644
--- a/service/usbip/usbhost_darwin.go
+++ b/service/usbip/usbhost_darwin.go
@@ -451,9 +451,10 @@ func darwinDeviceInfoFromC(info *C.box_usbhost_device_info_t) darwinUSBHostDevic
 			BNumConfigurations:  uint8(info.num_configurations),
 			BNumInterfaces:      uint8(info.interface_count),
 		},
+		Serial: serial,
 	}
 	copy(entry.Info.BusID[:], busid)
-	encodePathField(&entry.Info.Path, path, serial)
+	encodePathField(&entry.Info.Path, path)
 	interfaceCount := int(info.interface_count)
 	if interfaceCount > C.BOX_USBHOST_MAX_INTERFACES {
 		interfaceCount = C.BOX_USBHOST_MAX_INTERFACES