From febf1c49be1bd80d7c95653fc0caa87d250b2c72 Mon Sep 17 00:00:00 2001 From: Laszlo Ersek Date: Wed, 3 Jul 2013 15:14:08 +0200 Subject: [PATCH 1/3] qga/service-win32.c: diagnostic output should go to stderr Acked-by: Michael Roth Reviewed-by: Eric Blake Signed-off-by: Laszlo Ersek Signed-off-by: Michael Roth --- qga/service-win32.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/qga/service-win32.c b/qga/service-win32.c index 02926abb28..6de8be46be 100644 --- a/qga/service-win32.c +++ b/qga/service-win32.c @@ -29,7 +29,7 @@ static int printf_win_error(const char *text) MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (char *)&message, 0, NULL); - n = printf("%s. (Error: %d) %s", text, (int)err, message); + n = fprintf(stderr, "%s. (Error: %d) %s", text, (int)err, message); LocalFree(message); return n; @@ -78,7 +78,7 @@ int ga_install_service(const char *path, const char *logfile, SERVICE_DESCRIPTION desc = { (char *)QGA_SERVICE_DESCRIPTION }; ChangeServiceConfig2(service, SERVICE_CONFIG_DESCRIPTION, &desc); - printf("Service was installed successfully.\n"); + fprintf(stderr, "Service was installed successfully.\n"); } else { printf_win_error("Failed to install service"); } @@ -111,7 +111,7 @@ int ga_uninstall_service(void) if (DeleteService(service) == FALSE) { printf_win_error("Failed to delete service"); } else { - printf("Service was deleted successfully.\n"); + fprintf(stderr, "Service was deleted successfully.\n"); } CloseServiceHandle(service); From 108365fdb0042454413d2610ffe7194003ba4ae9 Mon Sep 17 00:00:00 2001 From: Laszlo Ersek Date: Wed, 3 Jul 2013 15:14:09 +0200 Subject: [PATCH 2/3] ga_install_service(): nest error paths more idiomatically Acked-by: Michael Roth Reviewed-by: Eric Blake Signed-off-by: Laszlo Ersek Signed-off-by: Michael Roth --- qga/service-win32.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/qga/service-win32.c b/qga/service-win32.c index 6de8be46be..1cf81fc96d 100644 --- a/qga/service-win32.c +++ b/qga/service-win32.c @@ -38,10 +38,12 @@ static int printf_win_error(const char *text) int ga_install_service(const char *path, const char *logfile, const char *state_dir) { + int ret = EXIT_FAILURE; SC_HANDLE manager; SC_HANDLE service; TCHAR module_fname[MAX_PATH]; GString *cmdline; + SERVICE_DESCRIPTION desc = { (char *)QGA_SERVICE_DESCRIPTION }; if (GetModuleFileName(NULL, module_fname, MAX_PATH) == 0) { printf_win_error("No full path to service's executable"); @@ -66,28 +68,28 @@ int ga_install_service(const char *path, const char *logfile, manager = OpenSCManager(NULL, NULL, SC_MANAGER_ALL_ACCESS); if (manager == NULL) { printf_win_error("No handle to service control manager"); - g_string_free(cmdline, TRUE); - return EXIT_FAILURE; + goto out_strings; } service = CreateService(manager, QGA_SERVICE_NAME, QGA_SERVICE_DISPLAY_NAME, SERVICE_ALL_ACCESS, SERVICE_WIN32_OWN_PROCESS, SERVICE_AUTO_START, SERVICE_ERROR_NORMAL, cmdline->str, NULL, NULL, NULL, NULL, NULL); - - if (service) { - SERVICE_DESCRIPTION desc = { (char *)QGA_SERVICE_DESCRIPTION }; - ChangeServiceConfig2(service, SERVICE_CONFIG_DESCRIPTION, &desc); - - fprintf(stderr, "Service was installed successfully.\n"); - } else { + if (service == NULL) { printf_win_error("Failed to install service"); + goto out_manager; } + ChangeServiceConfig2(service, SERVICE_CONFIG_DESCRIPTION, &desc); + fprintf(stderr, "Service was installed successfully.\n"); + ret = EXIT_SUCCESS; CloseServiceHandle(service); + +out_manager: CloseServiceHandle(manager); +out_strings: g_string_free(cmdline, TRUE); - return (service == NULL); + return ret; } int ga_uninstall_service(void) From 340d51df5592c5c11fc3885f7bdedbe581b87366 Mon Sep 17 00:00:00 2001 From: Laszlo Ersek Date: Wed, 3 Jul 2013 15:14:10 +0200 Subject: [PATCH 3/3] qga: escape cmdline args when registering win32 service (CVE-2013-2231) Reported-by: Lev Veyde Reviewed-by: Eric Blake Signed-off-by: Laszlo Ersek Signed-off-by: Michael Roth --- qga/service-win32.c | 79 ++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 74 insertions(+), 5 deletions(-) diff --git a/qga/service-win32.c b/qga/service-win32.c index 1cf81fc96d..aef41f04f1 100644 --- a/qga/service-win32.c +++ b/qga/service-win32.c @@ -35,6 +35,68 @@ static int printf_win_error(const char *text) return n; } +/* Windows command line escaping. Based on + * and + * . + * + * The caller is responsible for initializing @buffer; prior contents are lost. + */ +static const char *win_escape_arg(const char *to_escape, GString *buffer) +{ + size_t backslash_count; + const char *c; + + /* open with a double quote */ + g_string_assign(buffer, "\""); + + backslash_count = 0; + for (c = to_escape; *c != '\0'; ++c) { + switch (*c) { + case '\\': + /* The meaning depends on the first non-backslash character coming + * up. + */ + ++backslash_count; + break; + + case '"': + /* We must escape each pending backslash, then escape the double + * quote. This creates a case of "odd number of backslashes [...] + * followed by a double quotation mark". + */ + while (backslash_count) { + --backslash_count; + g_string_append(buffer, "\\\\"); + } + g_string_append(buffer, "\\\""); + break; + + default: + /* Any pending backslashes are without special meaning, flush them. + * "Backslashes are interpreted literally, unless they immediately + * precede a double quotation mark." + */ + while (backslash_count) { + --backslash_count; + g_string_append_c(buffer, '\\'); + } + g_string_append_c(buffer, *c); + } + } + + /* We're about to close with a double quote in string delimiter role. + * Double all pending backslashes, creating a case of "even number of + * backslashes [...] followed by a double quotation mark". + */ + while (backslash_count) { + --backslash_count; + g_string_append(buffer, "\\\\"); + } + g_string_append_c(buffer, '"'); + + return buffer->str; +} + int ga_install_service(const char *path, const char *logfile, const char *state_dir) { @@ -42,6 +104,7 @@ int ga_install_service(const char *path, const char *logfile, SC_HANDLE manager; SC_HANDLE service; TCHAR module_fname[MAX_PATH]; + GString *esc; GString *cmdline; SERVICE_DESCRIPTION desc = { (char *)QGA_SERVICE_DESCRIPTION }; @@ -50,17 +113,22 @@ int ga_install_service(const char *path, const char *logfile, return EXIT_FAILURE; } - cmdline = g_string_new(module_fname); - g_string_append(cmdline, " -d"); + esc = g_string_new(""); + cmdline = g_string_new(""); + + g_string_append_printf(cmdline, "%s -d", + win_escape_arg(module_fname, esc)); if (path) { - g_string_append_printf(cmdline, " -p %s", path); + g_string_append_printf(cmdline, " -p %s", win_escape_arg(path, esc)); } if (logfile) { - g_string_append_printf(cmdline, " -l %s -v", logfile); + g_string_append_printf(cmdline, " -l %s -v", + win_escape_arg(logfile, esc)); } if (state_dir) { - g_string_append_printf(cmdline, " -t %s", state_dir); + g_string_append_printf(cmdline, " -t %s", + win_escape_arg(state_dir, esc)); } g_debug("service's cmdline: %s", cmdline->str); @@ -89,6 +157,7 @@ out_manager: out_strings: g_string_free(cmdline, TRUE); + g_string_free(esc, TRUE); return ret; }