[bind] Return EINVAL for under sized address

...and EAFNOSUPPORT for unexpected address family.

To comply with Linux.

Updates #6021, #6575.

PiperOrigin-RevId: 396893590

pkg/sentry/socket/netstack/netstack.go

@@ -419,6 +419,27 @@ func bytesToIPAddress(addr []byte) tcpip.Address {
 	return tcpip.Address(addr)
 }
 
+// minSockAddrLen returns the minimum length in bytes of a socket address for
+// the socket's family.
+func (s *socketOpsCommon) minSockAddrLen() int {
+	const addressFamilySize = 2
+
+	switch s.family {
+	case linux.AF_UNIX:
+		return addressFamilySize
+	case linux.AF_INET:
+		return sockAddrInetSize
+	case linux.AF_INET6:
+		return sockAddrInet6Size
+	case linux.AF_PACKET:
+		return sockAddrLinkSize
+	case linux.AF_UNSPEC:
+		return addressFamilySize
+	default:
+		panic(fmt.Sprintf("s.family unrecognized = %d", s.family))
+	}
+}
+
 func (s *socketOpsCommon) isPacketBased() bool {
 	return s.skType == linux.SOCK_DGRAM || s.skType == linux.SOCK_SEQPACKET || s.skType == linux.SOCK_RDM || s.skType == linux.SOCK_RAW
 }
@@ -545,16 +566,21 @@ func (s *socketOpsCommon) Readiness(mask waiter.EventMask) waiter.EventMask {
 	return s.Endpoint.Readiness(mask)
 }
 
-func (s *socketOpsCommon) checkFamily(family uint16, exact bool) *syserr.Error {
+// checkFamily returns true iff the specified address family may be used with
+// the socket.
+//
+// If exact is true, then the specified address family must be an exact match
+// with the socket's family.
+func (s *socketOpsCommon) checkFamily(family uint16, exact bool) bool {
 	if family == uint16(s.family) {
-		return nil
+		return true
 	}
 	if !exact && family == linux.AF_INET && s.family == linux.AF_INET6 {
 		if !s.Endpoint.SocketOptions().GetV6Only() {
-			return nil
+			return true
 		}
 	}
-	return syserr.ErrInvalidArgument
+	return false
 }
 
 // mapFamily maps the AF_INET ANY address to the IPv4-mapped IPv6 ANY if the
@@ -587,8 +613,8 @@ func (s *socketOpsCommon) Connect(t *kernel.Task, sockaddr []byte, blocking bool
 		return syserr.TranslateNetstackError(err)
 	}
 
-	if err := s.checkFamily(family, false /* exact */); err != nil {
-		return err
+	if !s.checkFamily(family, false /* exact */) {
+		return syserr.ErrInvalidArgument
 	}
 	addr = s.mapFamily(addr, family)
 
@@ -655,14 +681,18 @@ func (s *socketOpsCommon) Bind(t *kernel.Task, sockaddr []byte) *syserr.Error {
 			Addr: tcpip.Address(a.HardwareAddr[:header.EthernetAddressSize]),
 		}
 	} else {
+		if s.minSockAddrLen() > len(sockaddr) {
+			return syserr.ErrInvalidArgument
+		}
+
 		var err *syserr.Error
 		addr, family, err = socket.AddressAndFamily(sockaddr)
 		if err != nil {
 			return err
 		}
 
-		if err = s.checkFamily(family, true /* exact */); err != nil {
-			return err
+		if !s.checkFamily(family, true /* exact */) {
+			return syserr.ErrAddressFamilyNotSupported
 		}
 
 		addr = s.mapFamily(addr, family)
@@ -2872,8 +2902,8 @@ func (s *socketOpsCommon) SendMsg(t *kernel.Task, src usermem.IOSequence, to []b
 		if err != nil {
 			return 0, err
 		}
-		if err := s.checkFamily(family, false /* exact */); err != nil {
-			return 0, err
+		if !s.checkFamily(family, false /* exact */) {
+			return 0, syserr.ErrInvalidArgument
 		}
 		addrBuf = s.mapFamily(addrBuf, family)
 

test/syscalls/linux/ping_socket.cc

@@ -155,43 +155,33 @@ std::vector<std::tuple<SocketKind, BindTestCase>> ICMPTestCases() {
               .bind_to = V4AddrStr("IPv4UnknownUnicast", "192.168.1.1"),
               .want = EADDRNOTAVAIL,
           },
-          // TODO(gvisor.dev/issue/6021): Remove want_gvisor from all the test
-          // cases below once ICMP sockets return EAFNOSUPPORT when binding to
-          // IPv6 addresses.
           {
               .bind_to = V6Any(),
               .want = EAFNOSUPPORT,
-              .want_gvisor = EINVAL,
           },
           {
               .bind_to = V6Loopback(),
               .want = EAFNOSUPPORT,
-              .want_gvisor = EINVAL,
           },
           {
               .bind_to = V6Multicast(),
               .want = EAFNOSUPPORT,
-              .want_gvisor = EINVAL,
           },
           {
               .bind_to = V6MulticastInterfaceLocalAllNodes(),
               .want = EAFNOSUPPORT,
-              .want_gvisor = EINVAL,
           },
           {
               .bind_to = V6MulticastLinkLocalAllNodes(),
               .want = EAFNOSUPPORT,
-              .want_gvisor = EINVAL,
           },
           {
               .bind_to = V6MulticastLinkLocalAllRouters(),
               .want = EAFNOSUPPORT,
-              .want_gvisor = EINVAL,
           },
           {
               .bind_to = V6AddrStr("IPv6UnknownUnicast", "fc00::1"),
               .want = EAFNOSUPPORT,
-              .want_gvisor = EINVAL,
           },
       });
 }

test/syscalls/linux/udp_socket.cc

@@ -643,12 +643,12 @@ TEST_P(UdpSocketTest, DisconnectAfterBindToUnspecAndConnect) {
 
   sockaddr_storage unspec = {.ss_family = AF_UNSPEC};
   int bind_res = bind(sock_.get(), AsSockAddr(&unspec), sizeof(unspec));
-  if (IsRunningOnGvisor() && !IsRunningWithHostinet()) {
-    // TODO(https://gvisor.dev/issue/6575): Match Linux's behaviour.
-    ASSERT_THAT(bind_res, SyscallFailsWithErrno(EINVAL));
-  } else if (GetFamily() == AF_INET) {
+  if ((!IsRunningOnGvisor() || IsRunningWithHostinet()) &&
+      GetFamily() == AF_INET) {
     // Linux allows this for undocumented compatibility reasons:
     // https://github.com/torvalds/linux/commit/29c486df6a208432b370bd4be99ae1369ede28d8.
+    //
+    // TODO(https://gvisor.dev/issue/6575): Match Linux's behaviour.
     ASSERT_THAT(bind_res, SyscallSucceeds());
   } else {
     ASSERT_THAT(bind_res, SyscallFailsWithErrno(EAFNOSUPPORT));