Re: [PATCH net v2 5/6] vsock/test: Add test for UAF due to socket unbinding
From: Stefano Garzarella <sgarzare@redhat.com>
Date: 2025-01-22 11:43:12
On Tue, Jan 21, 2025 at 03:44:06PM +0100, Michal Luczaj wrote:
Fail the autobind, then trigger a transport reassign. Socket might get unbound from unbound_sockets, which then leads to a reference count underflow. Signed-off-by: Michal Luczaj <redacted> --- tools/testing/vsock/vsock_test.c | 58 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+)
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
quoted hunk ↗ jump to hunk
diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c index 28a5083bbfd600cf84a1a85cec2f272ce6912dd3..572e0fd3e5a841f846fb304a24192f63d57ec052 100644 --- a/tools/testing/vsock/vsock_test.c +++ b/tools/testing/vsock/vsock_test.c@@ -1458,6 +1458,59 @@ static void test_stream_cred_upd_on_set_rcvlowat(const struct test_opts *opts)test_stream_credit_update_test(opts, false); } +#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) +{ + int sockets[MAX_PORT_RETRIES]; + struct sockaddr_vm addr; + int fd, i, alen; + + fd = vsock_bind(VMADDR_CID_ANY, VMADDR_PORT_ANY, SOCK_STREAM); + + alen = sizeof(addr); + if (getsockname(fd, (struct sockaddr *)&addr, &alen)) { + perror("getsockname"); + exit(EXIT_FAILURE); + } + + for (i = 0; i < MAX_PORT_RETRIES; ++i) + sockets[i] = vsock_bind(VMADDR_CID_ANY, ++addr.svm_port, + SOCK_STREAM); + + close(fd); + fd = socket(AF_VSOCK, SOCK_STREAM, 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"); + exit(EXIT_FAILURE); + } + + /* Vulnerable system may crash now. */ + if (!vsock_connect_fd(fd, VMADDR_CID_HOST, VMADDR_PORT_ANY)) { + perror("Unexpected connect() #2 success"); + exit(EXIT_FAILURE); + } + + close(fd); + while (i--) + close(sockets[i]); + + control_writeln("DONE"); +} + +static void test_stream_transport_uaf_server(const struct test_opts *opts) +{ + control_expectln("DONE"); +} + static struct test_case test_cases[] = { { .name = "SOCK_STREAM connection reset",@@ -1588,6 +1641,11 @@ static struct test_case test_cases[] = {.run_client = test_seqpacket_unsent_bytes_client, .run_server = test_seqpacket_unsent_bytes_server, }, + { + .name = "SOCK_STREAM transport release use-after-free", + .run_client = test_stream_transport_uaf_client, + .run_server = test_stream_transport_uaf_server, + }, {}, }; -- 2.48.1