diff options
| -rw-r--r-- | tools/testing/vsock/util.c | 80 | ||||
| -rw-r--r-- | tools/testing/vsock/util.h | 30 | ||||
| -rw-r--r-- | tools/testing/vsock/vsock_test.c | 93 |
3 files changed, 181 insertions, 22 deletions
diff --git a/tools/testing/vsock/util.c b/tools/testing/vsock/util.c index 0c7e9cbcbc85..803f1e075b62 100644 --- a/tools/testing/vsock/util.c +++ b/tools/testing/vsock/util.c @@ -7,6 +7,7 @@ * Author: Stefan Hajnoczi <stefanha@redhat.com> */ +#include <ctype.h> #include <errno.h> #include <stdio.h> #include <stdint.h> @@ -23,6 +24,9 @@ #include "control.h" #include "util.h" +#define KALLSYMS_PATH "/proc/kallsyms" +#define KALLSYMS_LINE_LEN 512 + /* Install signal handlers */ void init_signals(void) { @@ -121,15 +125,17 @@ bool vsock_wait_sent(int fd) return !ret; } -/* Create socket <type>, bind to <cid, port> and return the file descriptor. */ -int vsock_bind(unsigned int cid, unsigned int port, int type) +/* Create socket <type>, bind to <cid, port>. + * Return the file descriptor, or -1 on error. + */ +int vsock_bind_try(unsigned int cid, unsigned int port, int type) { struct sockaddr_vm sa = { .svm_family = AF_VSOCK, .svm_cid = cid, .svm_port = port, }; - int fd; + int fd, saved_errno; fd = socket(AF_VSOCK, type, 0); if (fd < 0) { @@ -138,6 +144,22 @@ int vsock_bind(unsigned int cid, unsigned int port, int type) } if (bind(fd, (struct sockaddr *)&sa, sizeof(sa))) { + saved_errno = errno; + close(fd); + errno = saved_errno; + fd = -1; + } + + return fd; +} + +/* Create socket <type>, bind to <cid, port> and return the file descriptor. */ +int vsock_bind(unsigned int cid, unsigned int port, int type) +{ + int fd; + + fd = vsock_bind_try(cid, port, type); + if (fd < 0) { perror("bind"); exit(EXIT_FAILURE); } @@ -836,3 +858,55 @@ void enable_so_linger(int fd, int timeout) exit(EXIT_FAILURE); } } + +static int __get_transports(void) +{ + char buf[KALLSYMS_LINE_LEN]; + const char *ksym; + int ret = 0; + FILE *f; + + f = fopen(KALLSYMS_PATH, "r"); + if (!f) { + perror("Can't open " KALLSYMS_PATH); + exit(EXIT_FAILURE); + } + + while (fgets(buf, sizeof(buf), f)) { + char *match; + int i; + + assert(buf[strlen(buf) - 1] == '\n'); + + for (i = 0; i < TRANSPORT_NUM; ++i) { + if (ret & BIT(i)) + continue; + + /* Match should be followed by '\t' or '\n'. + * See kallsyms.c:s_show(). + */ + ksym = transport_ksyms[i]; + match = strstr(buf, ksym); + if (match && isspace(match[strlen(ksym)])) { + ret |= BIT(i); + break; + } + } + } + + fclose(f); + return ret; +} + +/* Return integer with TRANSPORT_* bit set for every (known) registered vsock + * transport. + */ +int get_transports(void) +{ + static int tr = -1; + + if (tr == -1) + tr = __get_transports(); + + return tr; +} diff --git a/tools/testing/vsock/util.h b/tools/testing/vsock/util.h index 5e2db67072d5..71895192cc02 100644 --- a/tools/testing/vsock/util.h +++ b/tools/testing/vsock/util.h @@ -3,8 +3,36 @@ #define UTIL_H #include <sys/socket.h> +#include <linux/bitops.h> +#include <linux/kernel.h> #include <linux/vm_sockets.h> +/* All known vsock transports, see callers of vsock_core_register() */ +#define KNOWN_TRANSPORTS(x) \ + x(LOOPBACK, "loopback") \ + x(VIRTIO, "virtio") \ + x(VHOST, "vhost") \ + x(VMCI, "vmci") \ + x(HYPERV, "hvs") + +enum transport { + TRANSPORT_COUNTER_BASE = __COUNTER__ + 1, + #define x(name, symbol) \ + TRANSPORT_##name = BIT(__COUNTER__ - TRANSPORT_COUNTER_BASE), + KNOWN_TRANSPORTS(x) + TRANSPORT_NUM = __COUNTER__ - TRANSPORT_COUNTER_BASE, + #undef x +}; + +static const char * const transport_ksyms[] = { + #define x(name, symbol) "d " symbol "_transport", + KNOWN_TRANSPORTS(x) + #undef x +}; + +static_assert(ARRAY_SIZE(transport_ksyms) == TRANSPORT_NUM); +static_assert(BITS_PER_TYPE(int) >= TRANSPORT_NUM); + /* Tests can either run as the client or the server */ enum test_mode { TEST_MODE_UNSET, @@ -44,6 +72,7 @@ int vsock_connect(unsigned int cid, unsigned int port, int type); int vsock_accept(unsigned int cid, unsigned int port, struct sockaddr_vm *clientaddrp, int type); int vsock_stream_connect(unsigned int cid, unsigned int port); +int vsock_bind_try(unsigned int cid, unsigned int port, int type); int vsock_bind(unsigned int cid, unsigned int port, int type); int vsock_bind_connect(unsigned int cid, unsigned int port, unsigned int bind_port, int type); @@ -81,4 +110,5 @@ void setsockopt_timeval_check(int fd, int level, int optname, struct timeval val, char const *errmsg); void enable_so_zerocopy_check(int fd); void enable_so_linger(int fd, int timeout); +int get_transports(void); #endif /* UTIL_H */ diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c index f669baaa0dca..eb6f54378667 100644 --- a/tools/testing/vsock/vsock_test.c +++ b/tools/testing/vsock/vsock_test.c @@ -1718,16 +1718,27 @@ static void test_stream_msgzcopy_leak_zcskb_server(const struct test_opts *opts) #define MAX_PORT_RETRIES 24 /* net/vmw_vsock/af_vsock.c */ -/* Test attempts to trigger a transport release for an unbound socket. This can - * lead to a reference count mishandling. - */ -static void test_stream_transport_uaf_client(const struct test_opts *opts) +static bool test_stream_transport_uaf(int cid) { int sockets[MAX_PORT_RETRIES]; struct sockaddr_vm addr; - int fd, i, alen; + socklen_t alen; + int fd, i, c; + bool ret; + + /* Probe for a transport by attempting a local CID bind. Unavailable + * transport (or more specifically: an unsupported transport/CID + * combination) results in EADDRNOTAVAIL, other errnos are fatal. + */ + fd = vsock_bind_try(cid, VMADDR_PORT_ANY, SOCK_STREAM); + if (fd < 0) { + if (errno != EADDRNOTAVAIL) { + perror("Unexpected bind() errno"); + exit(EXIT_FAILURE); + } - fd = vsock_bind(VMADDR_CID_ANY, VMADDR_PORT_ANY, SOCK_STREAM); + return false; + } alen = sizeof(addr); if (getsockname(fd, (struct sockaddr *)&addr, &alen)) { @@ -1735,38 +1746,83 @@ static void test_stream_transport_uaf_client(const struct test_opts *opts) exit(EXIT_FAILURE); } + /* Drain the autobind pool; see __vsock_bind_connectible(). */ for (i = 0; i < MAX_PORT_RETRIES; ++i) - sockets[i] = vsock_bind(VMADDR_CID_ANY, ++addr.svm_port, - SOCK_STREAM); + sockets[i] = vsock_bind(cid, ++addr.svm_port, SOCK_STREAM); close(fd); - fd = socket(AF_VSOCK, SOCK_STREAM, 0); + + /* Setting SOCK_NONBLOCK makes connect() return soon after + * (re-)assigning the transport. We are not connecting to anything + * anyway, so there is no point entering the main loop in + * vsock_connect(); waiting for timeout, checking for signals, etc. + */ + fd = socket(AF_VSOCK, SOCK_STREAM | SOCK_NONBLOCK, 0); if (fd < 0) { perror("socket"); exit(EXIT_FAILURE); } - if (!vsock_connect_fd(fd, addr.svm_cid, addr.svm_port)) { - perror("Unexpected connect() #1 success"); + /* Assign transport, while failing to autobind. Autobind pool was + * drained, so EADDRNOTAVAIL coming from __vsock_bind_connectible() is + * expected. + * + * One exception is ENODEV which is thrown by vsock_assign_transport(), + * i.e. before vsock_auto_bind(), when the only transport loaded is + * vhost. + */ + if (!connect(fd, (struct sockaddr *)&addr, alen)) { + fprintf(stderr, "Unexpected connect() success\n"); exit(EXIT_FAILURE); } - - /* Vulnerable system may crash now. */ - if (!vsock_connect_fd(fd, VMADDR_CID_HOST, VMADDR_PORT_ANY)) { - perror("Unexpected connect() #2 success"); + if (errno == ENODEV && cid == VMADDR_CID_HOST) { + ret = false; + goto cleanup; + } + if (errno != EADDRNOTAVAIL) { + perror("Unexpected connect() errno"); exit(EXIT_FAILURE); } + /* Reassign transport, triggering old transport release and + * (potentially) unbinding of an unbound socket. + * + * Vulnerable system may crash now. + */ + for (c = VMADDR_CID_HYPERVISOR; c <= VMADDR_CID_HOST + 1; ++c) { + if (c != cid) { + addr.svm_cid = c; + (void)connect(fd, (struct sockaddr *)&addr, alen); + } + } + + ret = true; +cleanup: close(fd); while (i--) close(sockets[i]); - control_writeln("DONE"); + return ret; } -static void test_stream_transport_uaf_server(const struct test_opts *opts) +/* Test attempts to trigger a transport release for an unbound socket. This can + * lead to a reference count mishandling. + */ +static void test_stream_transport_uaf_client(const struct test_opts *opts) { - control_expectln("DONE"); + bool tested = false; + int cid, tr; + + for (cid = VMADDR_CID_HYPERVISOR; cid <= VMADDR_CID_HOST + 1; ++cid) + tested |= test_stream_transport_uaf(cid); + + tr = get_transports(); + if (!tr) + fprintf(stderr, "No transports detected\n"); + else if (tr == TRANSPORT_VIRTIO) + fprintf(stderr, "Setup unsupported: sole virtio transport\n"); + else if (!tested) + fprintf(stderr, "No transports tested\n"); } static void test_stream_connect_retry_client(const struct test_opts *opts) @@ -2034,7 +2090,6 @@ static struct test_case test_cases[] = { { .name = "SOCK_STREAM transport release use-after-free", .run_client = test_stream_transport_uaf_client, - .run_server = test_stream_transport_uaf_server, }, { .name = "SOCK_STREAM retry failed connect()", |