From a10389e783aab5f530641394ef44c8a1dede9372 Mon Sep 17 00:00:00 2001 From: Andrei Vagin Date: Wed, 8 Apr 2020 23:02:09 -0700 Subject: [PATCH] splice: cap splice calls to MAX_RW_COUNT The Linux does the same. Reported-by: syzbot+e81716e8956e92e9d56b@syzkaller.appspotmail.com PiperOrigin-RevId: 305625439 --- pkg/sentry/syscalls/linux/sys_splice.go | 4 + test/syscalls/linux/BUILD | 2 + test/syscalls/linux/sendfile_socket.cc | 105 +++++++++++------------- 3 files changed, 53 insertions(+), 58 deletions(-) diff --git a/pkg/sentry/syscalls/linux/sys_splice.go b/pkg/sentry/syscalls/linux/sys_splice.go index fd642834b..fbc6cf15f 100644 --- a/pkg/sentry/syscalls/linux/sys_splice.go +++ b/pkg/sentry/syscalls/linux/sys_splice.go @@ -29,6 +29,10 @@ func doSplice(t *kernel.Task, outFile, inFile *fs.File, opts fs.SpliceOpts, nonB return 0, syserror.EINVAL } + if opts.Length > int64(kernel.MAX_RW_COUNT) { + opts.Length = int64(kernel.MAX_RW_COUNT) + } + var ( total int64 n int64 diff --git a/test/syscalls/linux/BUILD b/test/syscalls/linux/BUILD index d0c431234..ae3017608 100644 --- a/test/syscalls/linux/BUILD +++ b/test/syscalls/linux/BUILD @@ -2026,6 +2026,8 @@ cc_binary( "//test/util:file_descriptor", "@com_google_absl//absl/strings", gtest, + ":ip_socket_test_util", + ":unix_domain_socket_test_util", "//test/util:temp_path", "//test/util:test_main", "//test/util:test_util", diff --git a/test/syscalls/linux/sendfile_socket.cc b/test/syscalls/linux/sendfile_socket.cc index e94672679..c101fe9d2 100644 --- a/test/syscalls/linux/sendfile_socket.cc +++ b/test/syscalls/linux/sendfile_socket.cc @@ -23,6 +23,7 @@ #include "gtest/gtest.h" #include "absl/strings/string_view.h" +#include "test/syscalls/linux/ip_socket_test_util.h" #include "test/syscalls/linux/socket_test_util.h" #include "test/util/file_descriptor.h" #include "test/util/temp_path.h" @@ -35,61 +36,39 @@ namespace { class SendFileTest : public ::testing::TestWithParam { protected: - PosixErrorOr> Sockets() { + PosixErrorOr> Sockets(int type) { // Bind a server socket. int family = GetParam(); - struct sockaddr server_addr = {}; switch (family) { case AF_INET: { - struct sockaddr_in* server_addr_in = - reinterpret_cast(&server_addr); - server_addr_in->sin_family = family; - server_addr_in->sin_addr.s_addr = INADDR_ANY; - break; + if (type == SOCK_STREAM) { + return SocketPairKind{ + "TCP", AF_INET, type, 0, + TCPAcceptBindSocketPairCreator(AF_INET, type, 0, false)} + .Create(); + } else { + return SocketPairKind{ + "UDP", AF_INET, type, 0, + UDPBidirectionalBindSocketPairCreator(AF_INET, type, 0, false)} + .Create(); + } } case AF_UNIX: { - struct sockaddr_un* server_addr_un = - reinterpret_cast(&server_addr); - server_addr_un->sun_family = family; - server_addr_un->sun_path[0] = '\0'; - break; + if (type == SOCK_STREAM) { + return SocketPairKind{ + "UNIX", AF_UNIX, type, 0, + FilesystemAcceptBindSocketPairCreator(AF_UNIX, type, 0)} + .Create(); + } else { + return SocketPairKind{ + "UNIX", AF_UNIX, type, 0, + FilesystemBidirectionalBindSocketPairCreator(AF_UNIX, type, 0)} + .Create(); + } } default: return PosixError(EINVAL); } - int server = socket(family, SOCK_STREAM, 0); - if (bind(server, &server_addr, sizeof(server_addr)) < 0) { - return PosixError(errno); - } - if (listen(server, 1) < 0) { - close(server); - return PosixError(errno); - } - - // Fetch the address; both are anonymous. - socklen_t length = sizeof(server_addr); - if (getsockname(server, &server_addr, &length) < 0) { - close(server); - return PosixError(errno); - } - - // Connect the client. - int client = socket(family, SOCK_STREAM, 0); - if (connect(client, &server_addr, length) < 0) { - close(server); - close(client); - return PosixError(errno); - } - - // Accept on the server. - int server_client = accept(server, nullptr, 0); - if (server_client < 0) { - close(server); - close(client); - return PosixError(errno); - } - close(server); - return std::make_tuple(client, server_client); } }; @@ -106,9 +85,7 @@ TEST_P(SendFileTest, SendMultiple) { const TempPath out_file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile()); // Create sockets. - std::tuple fds = ASSERT_NO_ERRNO_AND_VALUE(Sockets()); - const FileDescriptor server(std::get<0>(fds)); - FileDescriptor client(std::get<1>(fds)); // non-const, reset is used. + auto socks = ASSERT_NO_ERRNO_AND_VALUE(Sockets(SOCK_STREAM)); // Thread that reads data from socket and dumps to a file. ScopedThread th([&] { @@ -118,7 +95,7 @@ TEST_P(SendFileTest, SendMultiple) { // Read until socket is closed. char buf[10240]; for (int cnt = 0;; cnt++) { - int r = RetryEINTR(read)(server.get(), buf, sizeof(buf)); + int r = RetryEINTR(read)(socks->first_fd(), buf, sizeof(buf)); // We cannot afford to save on every read() call. if (cnt % 1000 == 0) { ASSERT_THAT(r, SyscallSucceeds()); @@ -152,7 +129,7 @@ TEST_P(SendFileTest, SendMultiple) { << ", remain=" << remain << std::endl; // Send data and verify that sendfile returns the correct value. - int res = sendfile(client.get(), inf.get(), nullptr, remain); + int res = sendfile(socks->second_fd(), inf.get(), nullptr, remain); // We cannot afford to save on every sendfile() call. if (cnt % 120 == 0) { MaybeSave(); @@ -169,7 +146,7 @@ TEST_P(SendFileTest, SendMultiple) { } // Close socket to stop thread. - client.reset(); + close(socks->release_second_fd()); th.Join(); // Verify that the output file has the correct data. @@ -183,9 +160,7 @@ TEST_P(SendFileTest, SendMultiple) { TEST_P(SendFileTest, Shutdown) { // Create a socket. - std::tuple fds = ASSERT_NO_ERRNO_AND_VALUE(Sockets()); - const FileDescriptor client(std::get<0>(fds)); - FileDescriptor server(std::get<1>(fds)); // non-const, reset below. + auto socks = ASSERT_NO_ERRNO_AND_VALUE(Sockets(SOCK_STREAM)); // If this is a TCP socket, then turn off linger. if (GetParam() == AF_INET) { @@ -193,7 +168,7 @@ TEST_P(SendFileTest, Shutdown) { sl.l_onoff = 1; sl.l_linger = 0; ASSERT_THAT( - setsockopt(server.get(), SOL_SOCKET, SO_LINGER, &sl, sizeof(sl)), + setsockopt(socks->first_fd(), SOL_SOCKET, SO_LINGER, &sl, sizeof(sl)), SyscallSucceeds()); } @@ -212,12 +187,12 @@ TEST_P(SendFileTest, Shutdown) { ScopedThread t([&]() { size_t done = 0; while (done < data.size()) { - int n = RetryEINTR(read)(server.get(), data.data(), data.size()); + int n = RetryEINTR(read)(socks->first_fd(), data.data(), data.size()); ASSERT_THAT(n, SyscallSucceeds()); done += n; } // Close the server side socket. - server.reset(); + close(socks->release_first_fd()); }); // Continuously stream from the file to the socket. Note we do not assert @@ -225,7 +200,7 @@ TEST_P(SendFileTest, Shutdown) { // data is written. Eventually, we should get a connection reset error. while (1) { off_t offset = 0; // Always read from the start. - int n = sendfile(client.get(), inf.get(), &offset, data.size()); + int n = sendfile(socks->second_fd(), inf.get(), &offset, data.size()); EXPECT_THAT(n, AnyOf(SyscallFailsWithErrno(ECONNRESET), SyscallFailsWithErrno(EPIPE), SyscallSucceeds())); if (n <= 0) { @@ -234,6 +209,20 @@ TEST_P(SendFileTest, Shutdown) { } } +TEST_P(SendFileTest, SendpageFromEmptyFileToUDP) { + auto socks = ASSERT_NO_ERRNO_AND_VALUE(Sockets(SOCK_DGRAM)); + + TempPath file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile()); + const FileDescriptor fd = + ASSERT_NO_ERRNO_AND_VALUE(Open(file.path(), O_RDWR)); + + // The value to the count argument has to be so that it is impossible to + // allocate a buffer of this size. In Linux, sendfile transfer at most + // 0x7ffff000 (MAX_RW_COUNT) bytes. + EXPECT_THAT(sendfile(socks->first_fd(), fd.get(), 0x0, 0x8000000000004), + SyscallSucceedsWithValue(0)); +} + INSTANTIATE_TEST_SUITE_P(AddressFamily, SendFileTest, ::testing::Values(AF_UNIX, AF_INET));