1 files changed, 243 insertions, 38 deletions

diff --git a/compat/mingw.c b/compat/mingw.c
index bd24d913f9..402c1ad91c 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -114,6 +114,7 @@ int err_win_to_posix(DWORD winerr)
 	case ERROR_SHARING_BUFFER_EXCEEDED: error = ENFILE; break;
 	case ERROR_SHARING_VIOLATION: error = EACCES; break;
 	case ERROR_STACK_OVERFLOW: error = ENOMEM; break;
+	case ERROR_SUCCESS: BUG("err_win_to_posix() called without an error!");
 	case ERROR_SWAPERROR: error = ENOENT; break;
 	case ERROR_TOO_MANY_MODULES: error = EMFILE; break;
 	case ERROR_TOO_MANY_OPEN_FILES: error = EMFILE; break;
@@ -212,6 +213,7 @@ enum hide_dotfiles_type {
 	HIDE_DOTFILES_DOTGITONLY
 };
 
+static int core_restrict_inherited_handles = -1;
 static enum hide_dotfiles_type hide_dotfiles = HIDE_DOTFILES_DOTGITONLY;
 static char *unset_environment_variables;
 
@@ -231,6 +233,15 @@ int mingw_core_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
+	if (!strcmp(var, "core.restrictinheritedhandles")) {
+		if (value && !strcasecmp(value, "auto"))
+			core_restrict_inherited_handles = -1;
+		else
+			core_restrict_inherited_handles =
+				git_config_bool(var, value);
+		return 0;
+	}
+
 	return 0;
 }
 
@@ -393,7 +404,7 @@ int mingw_mkdir(const char *path, int mode)
 	int ret;
 	wchar_t wpath[MAX_PATH];
 
-	if (!is_valid_win32_path(path)) {
+	if (!is_valid_win32_path(path, 0)) {
 		errno = EINVAL;
 		return -1;
 	}
@@ -479,21 +490,21 @@ int mingw_open (const char *filename, int oflags, ...)
 	mode = va_arg(args, int);
 	va_end(args);
 
-	if (!is_valid_win32_path(filename)) {
+	if (!is_valid_win32_path(filename, !create)) {
 		errno = create ? EINVAL : ENOENT;
 		return -1;
 	}
 
-	if (filename && !strcmp(filename, "/dev/null"))
-		filename = "nul";
-
 	if ((oflags & O_APPEND) && !is_local_named_pipe_path(filename))
 		open_fn = mingw_open_append;
 	else
 		open_fn = _wopen;
 
-	if (xutftowcs_path(wfilename, filename) < 0)
+	if (filename && !strcmp(filename, "/dev/null"))
+		wcscpy(wfilename, L"nul");
+	else if (xutftowcs_path(wfilename, filename) < 0)
 		return -1;
+
 	fd = open_fn(wfilename, oflags, mode);
 
 	if (fd < 0 && (oflags & O_ACCMODE) != O_RDONLY && errno == EACCES) {
@@ -550,16 +561,18 @@ FILE *mingw_fopen (const char *filename, const char *otype)
 	int hide = needs_hiding(filename);
 	FILE *file;
 	wchar_t wfilename[MAX_PATH], wotype[4];
-	if (!is_valid_win32_path(filename)) {
+	if (filename && !strcmp(filename, "/dev/null"))
+		wcscpy(wfilename, L"nul");
+	else if (!is_valid_win32_path(filename, 1)) {
 		int create = otype && strchr(otype, 'w');
 		errno = create ? EINVAL : ENOENT;
 		return NULL;
-	}
-	if (filename && !strcmp(filename, "/dev/null"))
-		filename = "nul";
-	if (xutftowcs_path(wfilename, filename) < 0 ||
-		xutftowcs(wotype, otype, ARRAY_SIZE(wotype)) < 0)
+	} else if (xutftowcs_path(wfilename, filename) < 0)
 		return NULL;
+
+	if (xutftowcs(wotype, otype, ARRAY_SIZE(wotype)) < 0)
+		return NULL;
+
 	if (hide && !access(filename, F_OK) && set_hidden_flag(wfilename, 0)) {
 		error("could not unhide %s", filename);
 		return NULL;
@@ -577,16 +590,18 @@ FILE *mingw_freopen (const char *filename, const char *otype, FILE *stream)
 	int hide = needs_hiding(filename);
 	FILE *file;
 	wchar_t wfilename[MAX_PATH], wotype[4];
-	if (!is_valid_win32_path(filename)) {
+	if (filename && !strcmp(filename, "/dev/null"))
+		wcscpy(wfilename, L"nul");
+	else if (!is_valid_win32_path(filename, 1)) {
 		int create = otype && strchr(otype, 'w');
 		errno = create ? EINVAL : ENOENT;
 		return NULL;
-	}
-	if (filename && !strcmp(filename, "/dev/null"))
-		filename = "nul";
-	if (xutftowcs_path(wfilename, filename) < 0 ||
-		xutftowcs(wotype, otype, ARRAY_SIZE(wotype)) < 0)
+	} else if (xutftowcs_path(wfilename, filename) < 0)
+		return NULL;
+
+	if (xutftowcs(wotype, otype, ARRAY_SIZE(wotype)) < 0)
 		return NULL;
+
 	if (hide && !access(filename, F_OK) && set_hidden_flag(wfilename, 0)) {
 		error("could not unhide %s", filename);
 		return NULL;
@@ -1007,16 +1022,16 @@ int pipe(int filedes[2])
 
 struct tm *gmtime_r(const time_t *timep, struct tm *result)
 {
-	/* gmtime() in MSVCRT.DLL is thread-safe, but not reentrant */
-	memcpy(result, gmtime(timep), sizeof(struct tm));
-	return result;
+	if (gmtime_s(result, timep) == 0)
+		return result;
+	return NULL;
 }
 
 struct tm *localtime_r(const time_t *timep, struct tm *result)
 {
-	/* localtime() in MSVCRT.DLL is thread-safe, but not reentrant */
-	memcpy(result, localtime(timep), sizeof(struct tm));
-	return result;
+	if (localtime_s(result, timep) == 0)
+		return result;
+	return NULL;
 }
 
 char *mingw_getcwd(char *pointer, int len)
@@ -1436,8 +1451,13 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **deltaen
 			      const char *dir,
 			      int prepend_cmd, int fhin, int fhout, int fherr)
 {
-	STARTUPINFOW si;
+	static int restrict_handle_inheritance = -1;
+	STARTUPINFOEXW si;
 	PROCESS_INFORMATION pi;
+	LPPROC_THREAD_ATTRIBUTE_LIST attr_list = NULL;
+	HANDLE stdhandles[3];
+	DWORD stdhandles_count = 0;
+	SIZE_T size;
 	struct strbuf args;
 	wchar_t wcmd[MAX_PATH], wdir[MAX_PATH], *wargs, *wenvblk = NULL;
 	unsigned flags = CREATE_UNICODE_ENVIRONMENT;
@@ -1447,6 +1467,19 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **deltaen
 		is_msys2_sh(cmd ? cmd : *argv) ?
 		quote_arg_msys2 : quote_arg_msvc;
 
+	/* Make sure to override previous errors, if any */
+	errno = 0;
+
+	if (restrict_handle_inheritance < 0)
+		restrict_handle_inheritance = core_restrict_inherited_handles;
+	/*
+	 * The following code to restrict which handles are inherited seems
+	 * to work properly only on Windows 7 and later, so let's disable it
+	 * on Windows Vista and 2008.
+	 */
+	if (restrict_handle_inheritance < 0)
+		restrict_handle_inheritance = GetVersion() >> 16 >= 7601;
+
 	do_unset_environment_variables();
 
 	/* Determine whether or not we are associated to a console */
@@ -1474,11 +1507,23 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **deltaen
 		CloseHandle(cons);
 	}
 	memset(&si, 0, sizeof(si));
-	si.cb = sizeof(si);
-	si.dwFlags = STARTF_USESTDHANDLES;
-	si.hStdInput = winansi_get_osfhandle(fhin);
-	si.hStdOutput = winansi_get_osfhandle(fhout);
-	si.hStdError = winansi_get_osfhandle(fherr);
+	si.StartupInfo.cb = sizeof(si);
+	si.StartupInfo.hStdInput = winansi_get_osfhandle(fhin);
+	si.StartupInfo.hStdOutput = winansi_get_osfhandle(fhout);
+	si.StartupInfo.hStdError = winansi_get_osfhandle(fherr);
+
+	/* The list of handles cannot contain duplicates */
+	if (si.StartupInfo.hStdInput != INVALID_HANDLE_VALUE)
+		stdhandles[stdhandles_count++] = si.StartupInfo.hStdInput;
+	if (si.StartupInfo.hStdOutput != INVALID_HANDLE_VALUE &&
+	    si.StartupInfo.hStdOutput != si.StartupInfo.hStdInput)
+		stdhandles[stdhandles_count++] = si.StartupInfo.hStdOutput;
+	if (si.StartupInfo.hStdError != INVALID_HANDLE_VALUE &&
+	    si.StartupInfo.hStdError != si.StartupInfo.hStdInput &&
+	    si.StartupInfo.hStdError != si.StartupInfo.hStdOutput)
+		stdhandles[stdhandles_count++] = si.StartupInfo.hStdError;
+	if (stdhandles_count)
+		si.StartupInfo.dwFlags |= STARTF_USESTDHANDLES;
 
 	if (*argv && !strcmp(cmd, *argv))
 		wcmd[0] = L'\0';
@@ -1511,16 +1556,98 @@ static pid_t mingw_spawnve_fd(const char *cmd, const char **argv, char **deltaen
 	wenvblk = make_environment_block(deltaenv);
 
 	memset(&pi, 0, sizeof(pi));
-	ret = CreateProcessW(*wcmd ? wcmd : NULL, wargs, NULL, NULL, TRUE,
-		flags, wenvblk, dir ? wdir : NULL, &si, &pi);
+	if (restrict_handle_inheritance && stdhandles_count &&
+	    (InitializeProcThreadAttributeList(NULL, 1, 0, &size) ||
+	     GetLastError() == ERROR_INSUFFICIENT_BUFFER) &&
+	    (attr_list = (LPPROC_THREAD_ATTRIBUTE_LIST)
+			(HeapAlloc(GetProcessHeap(), 0, size))) &&
+	    InitializeProcThreadAttributeList(attr_list, 1, 0, &size) &&
+	    UpdateProcThreadAttribute(attr_list, 0,
+				      PROC_THREAD_ATTRIBUTE_HANDLE_LIST,
+				      stdhandles,
+				      stdhandles_count * sizeof(HANDLE),
+				      NULL, NULL)) {
+		si.lpAttributeList = attr_list;
+		flags |= EXTENDED_STARTUPINFO_PRESENT;
+	}
+
+	ret = CreateProcessW(*wcmd ? wcmd : NULL, wargs, NULL, NULL,
+			     stdhandles_count ? TRUE : FALSE,
+			     flags, wenvblk, dir ? wdir : NULL,
+			     &si.StartupInfo, &pi);
+
+	/*
+	 * On Windows 2008 R2, it seems that specifying certain types of handles
+	 * (such as FILE_TYPE_CHAR or FILE_TYPE_PIPE) will always produce an
+	 * error. Rather than playing finicky and fragile games, let's just try
+	 * to detect this situation and simply try again without restricting any
+	 * handle inheritance. This is still better than failing to create
+	 * processes.
+	 */
+	if (!ret && restrict_handle_inheritance && stdhandles_count) {
+		DWORD err = GetLastError();
+		struct strbuf buf = STRBUF_INIT;
+
+		if (err != ERROR_NO_SYSTEM_RESOURCES &&
+		    /*
+		     * On Windows 7 and earlier, handles on pipes and character
+		     * devices are inherited automatically, and cannot be
+		     * specified in the thread handle list. Rather than trying
+		     * to catch each and every corner case (and running the
+		     * chance of *still* forgetting a few), let's just fall
+		     * back to creating the process without trying to limit the
+		     * handle inheritance.
+		     */
+		    !(err == ERROR_INVALID_PARAMETER &&
+		      GetVersion() >> 16 < 9200) &&
+		    !getenv("SUPPRESS_HANDLE_INHERITANCE_WARNING")) {
+			DWORD fl = 0;
+			int i;
+
+			setenv("SUPPRESS_HANDLE_INHERITANCE_WARNING", "1", 1);
+
+			for (i = 0; i < stdhandles_count; i++) {
+				HANDLE h = stdhandles[i];
+				strbuf_addf(&buf, "handle #%d: %p (type %lx, "
+					    "handle info (%d) %lx\n", i, h,
+					    GetFileType(h),
+					    GetHandleInformation(h, &fl),
+					    fl);
+			}
+			strbuf_addstr(&buf, "\nThis is a bug; please report it "
+				      "at\nhttps://github.com/git-for-windows/"
+				      "git/issues/new\n\n"
+				      "To suppress this warning, please set "
+				      "the environment variable\n\n"
+				      "\tSUPPRESS_HANDLE_INHERITANCE_WARNING=1"
+				      "\n");
+		}
+		restrict_handle_inheritance = 0;
+		flags &= ~EXTENDED_STARTUPINFO_PRESENT;
+		ret = CreateProcessW(*wcmd ? wcmd : NULL, wargs, NULL, NULL,
+				     TRUE, flags, wenvblk, dir ? wdir : NULL,
+				     &si.StartupInfo, &pi);
+		if (!ret)
+			errno = err_win_to_posix(GetLastError());
+		if (ret && buf.len) {
+			warning("failed to restrict file handles (%ld)\n\n%s",
+				err, buf.buf);
+		}
+		strbuf_release(&buf);
+	} else if (!ret)
+		errno = err_win_to_posix(GetLastError());
+
+	if (si.lpAttributeList)
+		DeleteProcThreadAttributeList(si.lpAttributeList);
+	if (attr_list)
+		HeapFree(GetProcessHeap(), 0, attr_list);
 
 	free(wenvblk);
 	free(wargs);
 
-	if (!ret) {
-		errno = ENOENT;
+	if (!ret)
 		return -1;
-	}
+
 	CloseHandle(pi.hThread);
 
 	/*
@@ -1605,7 +1732,7 @@ static int try_shell_exec(const char *cmd, char *const *argv)
 		while (argv[argc]) argc++;
 		ALLOC_ARRAY(argv2, argc + 1);
 		argv2[0] = (char *)cmd;	/* full path to the script file */
-		memcpy(&argv2[1], &argv[1], sizeof(*argv) * argc);
+		COPY_ARRAY(&argv2[1], &argv[1], argc);
 		exec_id = trace2_exec(prog, argv2);
 		pid = mingw_spawnv(prog, argv2, 1);
 		if (pid >= 0) {
@@ -2406,14 +2533,16 @@ static void setup_windows_environment(void)
 	}
 }
 
-int is_valid_win32_path(const char *path)
+int is_valid_win32_path(const char *path, int allow_literal_nul)
 {
+	const char *p = path;
 	int preceding_space_or_period = 0, i = 0, periods = 0;
 
 	if (!protect_ntfs)
 		return 1;
 
 	skip_dos_drive_prefix((char **)&path);
+	goto segment_start;
 
 	for (;;) {
 		char c = *(path++);
@@ -2428,7 +2557,83 @@ int is_valid_win32_path(const char *path)
 				return 1;
 
 			i = periods = preceding_space_or_period = 0;
-			continue;
+
+segment_start:
+			switch (*path) {
+			case 'a': case 'A': /* AUX */
+				if (((c = path[++i]) != 'u' && c != 'U') ||
+				    ((c = path[++i]) != 'x' && c != 'X')) {
+not_a_reserved_name:
+					path += i;
+					continue;
+				}
+				break;
+			case 'c': case 'C': /* COM<N>, CON, CONIN$, CONOUT$ */
+				if ((c = path[++i]) != 'o' && c != 'O')
+					goto not_a_reserved_name;
+				c = path[++i];
+				if (c == 'm' || c == 'M') { /* COM<N> */
+					if (!isdigit(path[++i]))
+						goto not_a_reserved_name;
+				} else if (c == 'n' || c == 'N') { /* CON */
+					c = path[i + 1];
+					if ((c == 'i' || c == 'I') &&
+					    ((c = path[i + 2]) == 'n' ||
+					     c == 'N') &&
+					    path[i + 3] == '$')
+						i += 3; /* CONIN$ */
+					else if ((c == 'o' || c == 'O') &&
+						 ((c = path[i + 2]) == 'u' ||
+						  c == 'U') &&
+						 ((c = path[i + 3]) == 't' ||
+						  c == 'T') &&
+						 path[i + 4] == '$')
+						i += 4; /* CONOUT$ */
+				} else
+					goto not_a_reserved_name;
+				break;
+			case 'l': case 'L': /* LPT<N> */
+				if (((c = path[++i]) != 'p' && c != 'P') ||
+				    ((c = path[++i]) != 't' && c != 'T') ||
+				    !isdigit(path[++i]))
+					goto not_a_reserved_name;
+				break;
+			case 'n': case 'N': /* NUL */
+				if (((c = path[++i]) != 'u' && c != 'U') ||
+				    ((c = path[++i]) != 'l' && c != 'L') ||
+				    (allow_literal_nul &&
+				     !path[i + 1] && p == path))
+					goto not_a_reserved_name;
+				break;
+			case 'p': case 'P': /* PRN */
+				if (((c = path[++i]) != 'r' && c != 'R') ||
+				    ((c = path[++i]) != 'n' && c != 'N'))
+					goto not_a_reserved_name;
+				break;
+			default:
+				continue;
+			}
+
+			/*
+			 * So far, this looks like a reserved name. Let's see
+			 * whether it actually is one: trailing spaces, a file
+			 * extension, or an NTFS Alternate Data Stream do not
+			 * matter, the name is still reserved if any of those
+			 * follow immediately after the actual name.
+			 */
+			i++;
+			if (path[i] == ' ') {
+				preceding_space_or_period = 1;
+				while (path[++i] == ' ')
+					; /* skip all spaces */
+			}
+
+			c = path[i];
+			if (c && c != '.' && c != ':' && c != '/' && c != '\\')
+				goto not_a_reserved_name;
+
+			/* contains reserved name */
+			return 0;
 		case '.':
 			periods++;
 			/* fallthru */