commit 1e5683b167a612bf76d4ae9ba508027e0d473e52 Author: Nick Mathewson nickm@torproject.org Date: Thu May 17 10:08:48 2012 -0400
Be more careful calling wcstombs
The function is not guaranteed to NUL-terminate its output. It *is*, however, guaranteed not to generate more than two bytes per multibyte character (plus terminating nul), so the general approach I'm taking is to try to allocate enough space, AND to manually add a NUL at the end of each buffer just in case I screwed up the "enough space" thing.
Fixes bug 5909. --- changes/bug5909 | 5 +++++ src/common/compat.c | 23 ++++++++++++++++------- src/common/util.c | 3 ++- src/or/config.c | 5 +++-- src/or/eventdns.c | 3 ++- src/or/ntmain.c | 3 ++- 6 files changed, 30 insertions(+), 12 deletions(-)
diff --git a/changes/bug5909 b/changes/bug5909 new file mode 100644 index 0000000..61990fa --- /dev/null +++ b/changes/bug5909 @@ -0,0 +1,5 @@ + o Major bugfixes: + - When building Tor on Windows with -DUNICODE (not default), + ensure that error messages, filenames, and DNS server names are + always NUL-terminated when we convert them to a single-byte + encoding. Fixes bug 5909; bugfix on 0.2.2.16-alpha. diff --git a/src/common/compat.c b/src/common/compat.c index 334ea1b..db2187b 100644 --- a/src/common/compat.c +++ b/src/common/compat.c @@ -3046,28 +3046,37 @@ format_win32_error(DWORD err) { TCHAR *str = NULL; char *result; + DWORD n;
/* Somebody once decided that this interface was better than strerror(). */ - FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | + n = FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, err, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), - (LPVOID)&str, + (LPVOID)&str, 0, NULL);
- if (str) { + if (str && n) { #ifdef UNICODE - char abuf[1024] = {0}; - wcstombs(abuf,str,1024); - result = tor_strdup(abuf); + size_t len; + if (n > 128*1024) + len = (128 * 1024) * 2 + 1; /* This shouldn't be possible, but let's + * make sure. */ + else + len = n * 2 + 1; + result = tor_malloc(len); + wcstombs(result,str,len); + result[len-1] = '\0'; #else result = tor_strdup(str); #endif - LocalFree(str); /* LocalFree != free() */ } else { result = tor_strdup("<unformattable error>"); } + if (str) { + LocalFree(str); /* LocalFree != free() */ + } return result; } #endif diff --git a/src/common/util.c b/src/common/util.c index 4c086e8..dc8f8b7 100644 --- a/src/common/util.c +++ b/src/common/util.c @@ -2855,7 +2855,7 @@ tor_listdir(const char *dirname) #ifdef _WIN32 char *pattern=NULL; TCHAR tpattern[MAX_PATH] = {0}; - char name[MAX_PATH] = {0}; + char name[MAX_PATH*2+1] = {0}; HANDLE handle; WIN32_FIND_DATA findData; tor_asprintf(&pattern, "%s\*", dirname); @@ -2872,6 +2872,7 @@ tor_listdir(const char *dirname) while (1) { #ifdef UNICODE wcstombs(name,findData.cFileName,MAX_PATH); + name[sizeof(name)-1] = '\0'; #else strlcpy(name,findData.cFileName,sizeof(name)); #endif diff --git a/src/or/config.c b/src/or/config.c index 090d96c..2e3ce64 100644 --- a/src/or/config.c +++ b/src/or/config.c @@ -4302,7 +4302,7 @@ static char * get_windows_conf_root(void) { static int is_set = 0; - static char path[MAX_PATH+1]; + static char path[MAX_PATH*2+1]; TCHAR tpath[MAX_PATH] = {0};
LPITEMIDLIST idl; @@ -4332,7 +4332,8 @@ get_windows_conf_root(void) /* Convert the path from an "ID List" (whatever that is!) to a path. */ result = SHGetPathFromIDList(idl, tpath); #ifdef UNICODE - wcstombs(path,tpath,MAX_PATH); + wcstombs(path,tpath,sizeof(path)); + path[sizeof(path)-1] = '\0'; #else strlcpy(path,tpath,sizeof(path)); #endif diff --git a/src/or/eventdns.c b/src/or/eventdns.c index 61a2836..768693a 100644 --- a/src/or/eventdns.c +++ b/src/or/eventdns.c @@ -3213,7 +3213,7 @@ static int config_nameserver_from_reg_key(HKEY key, const TCHAR *subkey) { char *buf; - char ansibuf[MAX_PATH] = {0}; + char ansibuf[MAX_PATH] = {0}; DWORD bufsz = 0, type = 0; int status = 0;
@@ -3226,6 +3226,7 @@ config_nameserver_from_reg_key(HKEY key, const TCHAR *subkey) if (RegQueryValueEx(key, subkey, 0, &type, (LPBYTE)buf, &bufsz) == ERROR_SUCCESS && bufsz > 1) { wcstombs(ansibuf,(wchar_t*)buf,MAX_PATH);/*XXXX UNICODE */ + abuf[MAX_PATH-1] = '\0'; status = evdns_nameserver_ip_add_line(ansibuf); }
diff --git a/src/or/ntmain.c b/src/or/ntmain.c index 01244c4..d001f7b 100644 --- a/src/or/ntmain.c +++ b/src/or/ntmain.c @@ -455,7 +455,7 @@ static char * nt_service_command_line(int *using_default_torrc) { TCHAR tor_exe[MAX_PATH+1]; - char tor_exe_ascii[MAX_PATH+1]; + char tor_exe_ascii[MAX_PATH*2+1]; char *command=NULL, *options=NULL; smartlist_t *sl; int i; @@ -483,6 +483,7 @@ nt_service_command_line(int *using_default_torrc)
#ifdef UNICODE wcstombs(tor_exe_ascii, tor_exe, sizeof(tor_exe_ascii)); + tor_exe_ascii[sizeof(tor_exe_ascii)-1] = '\0'; #else strlcpy(tor_exe_ascii, tor_exe, sizeof(tor_exe_ascii)); #endif