From f4b30e0b1d488e7ffd8ea28d1365b9ba8e551edb Mon Sep 17 00:00:00 2001 From: Matthieu Buffet Date: Wed, 1 Jul 2026 23:46:28 +0200 Subject: selftests/landlock: Add test for TCP fast open MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Enforce that TCP Fast Open is controlled by LANDLOCK_ACCESS_NET_CONNECT_TCP. Semantics of connect() and sendmsg(MSG_FASTOPEN) should be identical from Landlock's perspective. Also enforce error code consistency, since UDP sockets ignore the MSG_FASTOPEN flag while Unix sockets reject it. Signed-off-by: Matthieu Buffet Link: https://patch.msgid.link/20260701214628.33319-2-matthieu@buffet.re Cc: stable@vger.kernel.org [mic: Fix formatting] Signed-off-by: Mickaël Salaün --- tools/testing/selftests/landlock/net_test.c | 97 +++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) (limited to 'tools/testing') diff --git a/tools/testing/selftests/landlock/net_test.c b/tools/testing/selftests/landlock/net_test.c index 2ed1f76b7a8b..be2eb88092fb 100644 --- a/tools/testing/selftests/landlock/net_test.c +++ b/tools/testing/selftests/landlock/net_test.c @@ -1281,6 +1281,103 @@ TEST_F(protocol, connect_unspec) EXPECT_EQ(0, close(bind_fd)); } +TEST_F(protocol, tcp_fastopen) +{ + const bool restricted = variant->sandbox == TCP_SANDBOX && + variant->prot.type == SOCK_STREAM && + (variant->prot.protocol == IPPROTO_TCP || + variant->prot.protocol == IPPROTO_IP) && + (variant->prot.domain == AF_INET || + variant->prot.domain == AF_INET6); + const struct landlock_ruleset_attr ruleset_attr = { + .handled_access_net = LANDLOCK_ACCESS_NET_CONNECT_TCP, + }; + int bind_fd, client_fd, status; + char buf; + pid_t child; + + bind_fd = socket_variant(&self->srv0); + ASSERT_LE(0, bind_fd); + EXPECT_EQ(0, bind_variant(bind_fd, &self->srv0)); + if (self->srv0.protocol.type == SOCK_STREAM) + EXPECT_EQ(0, listen(bind_fd, backlog)); + + child = fork(); + ASSERT_LE(0, child); + if (child == 0) { + int connect_fd, ret; + + /* Closes listening socket for the child. */ + EXPECT_EQ(0, close(bind_fd)); + + connect_fd = socket_variant(&self->srv0); + ASSERT_LE(0, connect_fd); + + if (variant->sandbox == TCP_SANDBOX) { + const int ruleset_fd = landlock_create_ruleset( + &ruleset_attr, sizeof(ruleset_attr), 0); + ASSERT_LE(0, ruleset_fd); + + enforce_ruleset(_metadata, ruleset_fd); + EXPECT_EQ(0, close(ruleset_fd)); + } + + /* Fast Open with no address. */ + ret = sendto_variant(connect_fd, NULL, NULL, 0, MSG_FASTOPEN); + if (self->srv0.protocol.domain == AF_UNIX) { + EXPECT_EQ(-ENOTCONN, ret); + } else if (self->srv0.protocol.type == SOCK_DGRAM) { + EXPECT_EQ(-EDESTADDRREQ, ret); + } else { + EXPECT_EQ(-EINVAL, ret); + } + + /* Fast Open to a denied address. */ + ret = sendto_variant(connect_fd, &self->srv0, "A", 1, + MSG_FASTOPEN); + if (restricted) { + EXPECT_EQ(-EACCES, ret); + } else if (self->srv0.protocol.domain == AF_UNIX && + self->srv0.protocol.type == SOCK_STREAM) { + EXPECT_EQ(-EOPNOTSUPP, ret); + } else { + EXPECT_EQ(0, ret); + } + + EXPECT_EQ(0, close(connect_fd)); + _exit(_metadata->exit_code); + return; + } + + client_fd = bind_fd; + if (!restricted && self->srv0.protocol.type == SOCK_STREAM && + self->srv0.protocol.domain != AF_UNIX) { + client_fd = accept(bind_fd, NULL, 0); + ASSERT_LE(0, client_fd); + } + + if (restricted) { + EXPECT_EQ(-1, read(client_fd, &buf, 1)); + EXPECT_EQ(ENOTCONN, errno); + } else if (self->srv0.protocol.domain == AF_UNIX && + self->srv0.protocol.type == SOCK_STREAM) { + EXPECT_EQ(-1, read(client_fd, &buf, 1)); + EXPECT_EQ(EINVAL, errno); + } else { + EXPECT_EQ(1, read(client_fd, &buf, 1)); + EXPECT_EQ('A', buf); + } + + EXPECT_EQ(child, waitpid(child, &status, 0)); + EXPECT_EQ(1, WIFEXITED(status)); + EXPECT_EQ(EXIT_SUCCESS, WEXITSTATUS(status)); + + if (client_fd != bind_fd) + EXPECT_LE(0, close(client_fd)); + + EXPECT_EQ(0, close(bind_fd)); +} + TEST_F(protocol, sendmsg_stream) { int srv0_fd, tmp_fd, client_fd, res; -- cgit v1.2.3 From d793186aa3bb833c878ae6826c87e62c843afaa3 Mon Sep 17 00:00:00 2001 From: Thomas Huth Date: Thu, 9 Jul 2026 18:43:40 +0200 Subject: selftests/landlock: Fix screwed up pointers in the scoped_signal_test MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The scoped_signal_test uses pthread_join(..., (void **)&ret)) in a couple of places, i.e. the return value of the thread is stored in the shape of a "void *" into the memory location of &ret. Pointers are 64-bit on modern computers, but the ret variable is declared as a simple "enum thread_return" which is only 32 bits. So the pthread_join() will overflow the ret variable by 4 byte. The problem is very visible on big endian systems like s390x where the test is failing: The least significant byte that carries the return code of the thread is not written into the ret variable here, but somewhere else in the stack frame, so the comparison for the right return code is failing here. Fix it by getting rid of the enum and defining the THREAD_* constants and "ret" variables as proper "void *" pointers. This way we can also get rid of some ugly (void *) castings in a couple of spots. Signed-off-by: Thomas Huth Link: https://patch.msgid.link/20260709164340.339656-1-thuth@redhat.com Cc: stable@vger.kernel.org Fixes: c8994965013e ("selftests/landlock: Test signal scoping for threads") [mic: Add clang-format markups] Signed-off-by: Mickaël Salaün --- .../selftests/landlock/scoped_signal_test.c | 46 +++++++++++----------- 1 file changed, 23 insertions(+), 23 deletions(-) (limited to 'tools/testing') diff --git a/tools/testing/selftests/landlock/scoped_signal_test.c b/tools/testing/selftests/landlock/scoped_signal_test.c index f24f2c28f62e..3f0cd42a2afe 100644 --- a/tools/testing/selftests/landlock/scoped_signal_test.c +++ b/tools/testing/selftests/landlock/scoped_signal_test.c @@ -249,12 +249,12 @@ TEST_F(scoped_domains, check_access_signal) _metadata->exit_code = KSFT_FAIL; } -enum thread_return { - THREAD_INVALID = 0, - THREAD_SUCCESS = 1, - THREAD_ERROR = 2, - THREAD_TEST_FAILED = 3, -}; +/* clang-format off */ +#define THREAD_INVALID ((void *)0) +#define THREAD_SUCCESS ((void *)1) +#define THREAD_ERROR ((void *)2) +#define THREAD_TEST_FAILED ((void *)3) +/* clang-format on */ static void *thread_sync(void *arg) { @@ -262,15 +262,15 @@ static void *thread_sync(void *arg) char buf; if (read(pipe_read, &buf, 1) != 1) - return (void *)THREAD_ERROR; + return THREAD_ERROR; - return (void *)THREAD_SUCCESS; + return THREAD_SUCCESS; } TEST(signal_scoping_thread_before) { pthread_t no_sandbox_thread; - enum thread_return ret = THREAD_INVALID; + void *ret = THREAD_INVALID; int thread_pipe[2]; drop_caps(_metadata); @@ -285,7 +285,7 @@ TEST(signal_scoping_thread_before) EXPECT_EQ(0, pthread_kill(no_sandbox_thread, 0)); EXPECT_EQ(1, write(thread_pipe[1], ".", 1)); - EXPECT_EQ(0, pthread_join(no_sandbox_thread, (void **)&ret)); + EXPECT_EQ(0, pthread_join(no_sandbox_thread, &ret)); EXPECT_EQ(THREAD_SUCCESS, ret); EXPECT_EQ(0, close(thread_pipe[0])); @@ -295,7 +295,7 @@ TEST(signal_scoping_thread_before) TEST(signal_scoping_thread_after) { pthread_t scoped_thread; - enum thread_return ret = THREAD_INVALID; + void *ret = THREAD_INVALID; int thread_pipe[2]; drop_caps(_metadata); @@ -310,7 +310,7 @@ TEST(signal_scoping_thread_after) EXPECT_EQ(0, pthread_kill(scoped_thread, 0)); EXPECT_EQ(1, write(thread_pipe[1], ".", 1)); - EXPECT_EQ(0, pthread_join(scoped_thread, (void **)&ret)); + EXPECT_EQ(0, pthread_join(scoped_thread, &ret)); EXPECT_EQ(THREAD_SUCCESS, ret); EXPECT_EQ(0, close(thread_pipe[0])); @@ -327,20 +327,20 @@ void *thread_setuid(void *ptr) char buf; if (read(arg->pipe_read, &buf, 1) != 1) - return (void *)THREAD_ERROR; + return THREAD_ERROR; /* libc's setuid() should update all thread's credentials. */ if (getuid() != arg->new_uid) - return (void *)THREAD_TEST_FAILED; + return THREAD_TEST_FAILED; - return (void *)THREAD_SUCCESS; + return THREAD_SUCCESS; } TEST(signal_scoping_thread_setuid) { struct thread_setuid_args arg; pthread_t no_sandbox_thread; - enum thread_return ret = THREAD_INVALID; + void *ret = THREAD_INVALID; int pipe_parent[2]; int prev_uid; @@ -367,7 +367,7 @@ TEST(signal_scoping_thread_setuid) EXPECT_EQ(arg.new_uid, getuid()); EXPECT_EQ(1, write(pipe_parent[1], ".", 1)); - EXPECT_EQ(0, pthread_join(no_sandbox_thread, (void **)&ret)); + EXPECT_EQ(0, pthread_join(no_sandbox_thread, &ret)); EXPECT_EQ(THREAD_SUCCESS, ret); clear_cap(_metadata, CAP_SETUID); @@ -667,20 +667,20 @@ static void *thread_setown_scoped(void *arg) ruleset_fd = landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0); if (ruleset_fd < 0) - return (void *)THREAD_ERROR; + return THREAD_ERROR; if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) || landlock_restrict_self(ruleset_fd, 0)) { close(ruleset_fd); - return (void *)THREAD_ERROR; + return THREAD_ERROR; } close(ruleset_fd); /* Makes this process group own the SIGIO source. */ if (fcntl(fd, F_SETSIG, SIGURG) || fcntl(fd, F_SETOWN, -getpgrp()) || fcntl(fd, F_SETFL, O_ASYNC)) - return (void *)THREAD_ERROR; + return THREAD_ERROR; - return (void *)THREAD_SUCCESS; + return THREAD_SUCCESS; } /* @@ -702,7 +702,7 @@ TEST(sigio_to_pgid_self) { int trigger[2]; pthread_t thread; - enum thread_return ret = THREAD_INVALID; + void *ret = THREAD_INVALID; int i; drop_caps(_metadata); @@ -722,7 +722,7 @@ TEST(sigio_to_pgid_self) */ ASSERT_EQ(0, pthread_create(&thread, NULL, thread_setown_scoped, &trigger[0])); - ASSERT_EQ(0, pthread_join(thread, (void **)&ret)); + ASSERT_EQ(0, pthread_join(thread, &ret)); ASSERT_EQ(THREAD_SUCCESS, ret); /* Fans SIGURG out to the process group. */ -- cgit v1.2.3 From 5ab1dc6d110db6bee167a32fd94c53ea0e7ad6d2 Mon Sep 17 00:00:00 2001 From: Thomas Huth Date: Fri, 10 Jul 2026 10:16:42 +0200 Subject: selftests/landlock: Skip scoped_signal subtest with MSG_OOB if not available MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit MSG_OOB might be disabled in the kernel for unix sockets (by not selecting CONFIG_AF_UNIX_OOB), and in this case the related tests of the scoped_signal_test are currently failing. Add a runtime probe using socketpair() to detect MSG_OOB support and skip the test gracefully if it is unavailable. Signed-off-by: Thomas Huth Link: https://patch.msgid.link/20260710081642.405916-1-thuth@redhat.com Cc: stable@vger.kernel.org Fixes: f34e9ce5f479 ("selftests/landlock: Test signal created by out-of-bound message") Signed-off-by: Mickaël Salaün --- .../testing/selftests/landlock/scoped_signal_test.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'tools/testing') diff --git a/tools/testing/selftests/landlock/scoped_signal_test.c b/tools/testing/selftests/landlock/scoped_signal_test.c index 3f0cd42a2afe..2d37d0c06c06 100644 --- a/tools/testing/selftests/landlock/scoped_signal_test.c +++ b/tools/testing/selftests/landlock/scoped_signal_test.c @@ -400,6 +400,24 @@ static int setup_signal_handler(int signal) return sigaction(SIGURG, &sa, NULL); } +/* + * MSG_OOB might be disabled in the kernel via the CONFIG_AF_UNIX_OOB + * switch, so this function can be used for probing for its availability. + */ +static bool has_af_unix_oob(void) +{ + bool available = false; + int sp[2]; + + if (socketpair(AF_UNIX, SOCK_STREAM, 0, sp) == 0) { + available = (send(sp[0], ".", 1, MSG_OOB) == 1); + close(sp[0]); + close(sp[1]); + } + + return available; +} + /* clang-format off */ FIXTURE(fown) {}; /* clang-format on */ @@ -462,6 +480,9 @@ TEST_F(fown, sigurg_socket) int pipe_parent[2], pipe_child[2]; pid_t child; + if (!has_af_unix_oob()) + SKIP(return, "CONFIG_AF_UNIX_OOB / MSG_OOB not available"); + memset(&server_address, 0, sizeof(server_address)); set_unix_address(&server_address, 0); -- cgit v1.2.3