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Teach VM not to dump core on long pathnames

Long input paths (longer than MAX_PATH) would get copied
into a buffer of size MAX_PATH for read_link and altname
in efile_drv.
Also fixed misuse of size_t parameter as wchar_t *
string length in win_efile:efile_readlink.
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1 parent da477e3 commit cf6d1faf367b47c79ded23afc0d3fd3f38abfaea @bufflig bufflig committed Aug 27, 2012
@@ -206,6 +206,9 @@ dt_private *get_dt_private(int);
# define KEY(desc) (&(desc)->key)
#endif
+#ifndef MAX
+# define MAX(x, y) (((x) > (y)) ? (x) : (y))
+#endif
#ifdef FILENAMES_16BIT
#ifdef USE_VM_PROBES
@@ -2848,8 +2851,9 @@ file_output(ErlDrvData e, char* buf, ErlDrvSizeT count)
case FILE_READLINK:
{
- d = EF_SAFE_ALLOC(sizeof(struct t_data) - 1 + RESBUFSIZE + 1);
-
+ d = EF_SAFE_ALLOC(sizeof(struct t_data) - 1 +
+ MAX(RESBUFSIZE, (FILENAME_BYTELEN(name) +
+ FILENAME_CHARSIZE)) + 1);
FILENAME_COPY(d->b, name);
#ifdef USE_VM_PROBES
dt_s1 = d->b;
@@ -2864,7 +2868,9 @@ file_output(ErlDrvData e, char* buf, ErlDrvSizeT count)
case FILE_ALTNAME:
{
- d = EF_SAFE_ALLOC(sizeof(struct t_data) - 1 + RESBUFSIZE + 1);
+ d = EF_SAFE_ALLOC(sizeof(struct t_data) - 1 +
+ MAX(RESBUFSIZE, (FILENAME_BYTELEN(name) +
+ FILENAME_CHARSIZE)) + 1);
FILENAME_COPY(d->b, name);
#ifdef USE_VM_PROBES
dt_s1 = d->b;
@@ -897,7 +897,8 @@ efile_fileinfo(Efile_error* errInfo, Efile_info* pInfo,
we should be able to find its target */
WCHAR target_name[_MAX_PATH];
if (efile_readlink(errInfo, (char *) name,
- (char *) target_name,256) == 1) {
+ (char *) target_name,
+ _MAX_PATH * sizeof(WCHAR)) == 1) {
FindClose(findhandle);
return efile_fileinfo(errInfo, pInfo,
(char *) target_name, info_for_link);
@@ -1386,7 +1387,7 @@ efile_readlink(Efile_error* errInfo, char* name, char* buffer, size_t size)
HANDLE h = CreateFileW(wname, GENERIC_READ, 0,NULL, OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, NULL);
int len;
if(h != INVALID_HANDLE_VALUE) {
- success = pGetFinalPathNameByHandle(h, wbuffer, size,0);
+ success = pGetFinalPathNameByHandle(h, wbuffer, size / sizeof(WCHAR),0);
/* GetFinalPathNameByHandle prepends path with "\\?\": */
len = wcslen(wbuffer);
wmemmove(wbuffer,wbuffer+4,len-3);
@@ -2358,6 +2358,7 @@ symlinks(doc) -> "Test operations on symbolic links (for Unix).";
symlinks(suite) -> [];
symlinks(Config) when is_list(Config) ->
?line Dog = test_server:timetrap(test_server:seconds(10)),
+ ?line {error, _} = ?FILE_MODULE:read_link(lists:duplicate(10000,$a)),
?line RootDir = ?config(priv_dir, Config),
?line NewDir = filename:join(RootDir,
atom_to_list(?MODULE)

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