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Fix descriptor leaks in win32 fstat implementation #329

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Merged
merged 2 commits into from
Jul 13, 2018
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Fix descriptor leaks in win32 fstat implementation #329

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4428414
Fix descriptor leaks in win32 fstat implementation
cbookg Jul 11, 2018
046e082
Fix spaces I added to tabs.
cbookg Jul 12, 2018
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14 changes: 12 additions & 2 deletions contrib/win32/win32compat/fileio.c
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Original file line number Diff line number Diff line change
Expand Up @@ -769,14 +769,24 @@ fileio_write(struct w32_io* pio, const void *buf, size_t max_bytes)
int
fileio_fstat(struct w32_io* pio, struct _stat64 *buf)
{
int fd = _open_osfhandle((intptr_t)pio->handle, 0);
HANDLE dup_handle = 0;
if (!DuplicateHandle(GetCurrentProcess(), pio->handle, GetCurrentProcess(), &dup_handle, 0,
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I don't think we need to duplicate handle here..
when you do _open_osfhandle it will return the c run-time file descriptor. If you close the c run-time file descriptor then it shouldn't have any impact on the os handle (pio->handle).

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According to the docs for _open_osfhandle, _close will close the underlying handle:
"To close a file opened with , call _close. The underlying handle is also closed by a call to _close, so it is not necessary to call the Win32 function CloseHandle on the original handle"

Though I'm not an expert in these APIs.

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My bad, I didn't read the msdn documentation properly.. You are right.

TRUE, DUPLICATE_SAME_ACCESS)) {
errno = EOTHER;
return -1;
}

int fd = _open_osfhandle(dup_handle, 0);
debug4("fstat - pio:%p", pio);
if (fd == -1) {
CloseHandle(dup_handle);
errno = EOTHER;
return -1;
}

return _fstat64(fd, buf);
int res = _fstat64(fd, buf);
_close(fd);
return res;
}

int
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