# [PATCH] fix crash in solaris when fdopen() fails

- Thread: https://externals.io/message/15890
- Original archive: https://news-web.php.net/php.internals/15890
- Started by Uwe Schindler on 2005-04-07T07:40:43+00:00
- Messages: 5
- Reply by email to internals@lists.php.net
- More for agents: search with https://externals.io/search.md?q={query} · JSON API at https://externals.io/api · documentation at https://externals.io/llms.txt

---

## #15890 — Uwe Schindler — 2005-04-07T07:40:43+00:00

URL: https://externals.io/message/15890#15890

I am fixing bug #32614: Problem, on the solaris platform fdopen() can fail 
even if fd is a correct file descriptor, when fd>255 (the well-known 
solaris stdio problem). The webserver of the user crashes because the 
return value of fdopen() is not checked for `NULL` when casting a stream from 
posix to stdio. After this fd==-1 and fp==NULL ==> further calls to 
fread/fwrite with this fp segfault.
I committed the patches for PHP but I have no karme for "ZendEngine2". Can 
someone with karma submit this patch?

According to this it would be interesting, WHEN some PHP/Zend code tries to 
cast a POSIX stream to stdio? In which extension/functions? Can this be 
fixed to only use posix IO? The zend engine itself should be safe since 
4.3.3 and since PHP5.

Does stream casts apply if a user uses the PHP user functions fopen, fread, 
fwrite? Since Saschas fix in PHP4 there this does not happen. What about PHP5?

I would try to fix this everywhere in the future.

-----
Uwe Schindler
thetaphi@php.net - http://www.php.net
NSAPI SAPI developer
Erlangen, Germany

---

## #15902 — Uwe Schindler — 2005-04-08T14:58:39+00:00

URL: https://externals.io/message/15890#15902 · In reply to: #15890

OK - I found out that the fdopen() code is never called in the PHP 
environment, so patch is not needed (PHP sets zend_file_handle always to 
STREAM). But I still want to know for what extensions/functions the casts 
from posix to stdio are needed- Will casting appear somewhere when the user 
calls the userlevel-file-functions starting with `fopen()`?. It is hard work 
to find out with simple search through CVS.
The only position I know is because of `popen()` etc. in the exec functions 
which are stdio (posix variants are more complicated), which is the cause 
for the bug report I mentioned.

At 09:40 07.04.2005, Uwe Schindler wrote:
>I am fixing bug #32614: Problem, on the solaris platform fdopen() can fail 
>even if fd is a correct file descriptor, when fd>255 (the well-known 
>solaris stdio problem). The webserver of the user crashes because the 
>return value of fdopen() is not checked for `NULL` when casting a stream 
>from posix to stdio. After this fd==-1 and fp==NULL ==> further calls to 
>fread/fwrite with this fp segfault.
>I committed the patches for PHP but I have no karme for "ZendEngine2". Can 
>someone with karma submit this patch?
>
>According to this it would be interesting, WHEN some PHP/Zend code tries 
>to cast a POSIX stream to stdio? In which extension/functions? Can this be 
>fixed to only use posix IO? The zend engine itself should be safe since 
>4.3.3 and since PHP5.
>
>Does stream casts apply if a user uses the PHP user functions fopen, 
>fread, fwrite? Since Saschas fix in PHP4 there this does not happen. What 
>about PHP5?
>
>I would try to fix this everywhere in the future.
>
>-----
>Uwe Schindler
>thetaphi@php.net - http://www.php.net
>NSAPI SAPI developer
>Erlangen, Germany
>
>
>
>--
>
>

-----
Uwe Schindler
thetaphi@php.net - http://www.php.net
NSAPI SAPI developer
Bremen, Germany

---

## #15908 — Wez Furlong — 2005-04-08T15:42:41+00:00

URL: https://externals.io/message/15890#15908 · In reply to: #15902

Yeah, popen is tricky to replace.
A workaround for solaris is to use `proc_open()` in the scripts instead.
Other extensions that might have issues are those that will accept a
stream to use as a source for data.  Off the top of my head, you'll
want to check the PDFlib and ming extensions.  Actually, you be able
to grep the php source to see where the php_stream_cast function is
called; that'll highlight problem areas pretty easily I should think.

--Wez.


> OK - I found out that the fdopen() code is never called in the PHP
> environment, so patch is not needed (PHP sets zend_file_handle always to
> STREAM). But I still want to know for what extensions/functions the casts
> from posix to stdio are needed- Will casting appear somewhere when the user
> calls the userlevel-file-functions starting with `fopen()`?. It is hard work
> to find out with simple search through CVS.
> The only position I know is because of `popen()` etc. in the exec functions
> which are stdio (posix variants are more complicated), which is the cause
> for the bug report I mentioned.
> 
> At 09:40 07.04.2005, Uwe Schindler wrote:
> > […]
> 
> -----
> Uwe Schindler
> thetaphi@php.net - http://www.php.net
> NSAPI SAPI developer
> Bremen, Germany

---

## #15921 — Andi Gutmans — 2005-04-08T23:46:23+00:00

URL: https://externals.io/message/15890#15921 · In reply to: #15890

Not sure. Wez or Sara know that part of the code best.
I'll refrain from applying to the Zend Engine then or should I apply that 
patch anyway? It seems quite harmless either way...

Andi

At 04:58 PM 4/8/2005 +0200, Uwe Schindler wrote:
>OK - I found out that the fdopen() code is never called in the PHP 
>environment, so patch is not needed (PHP sets zend_file_handle always to 
>STREAM). But I still want to know for what extensions/functions the casts 
>from posix to stdio are needed- Will casting appear somewhere when the 
>user calls the userlevel-file-functions starting with `fopen()`?. It is hard 
>work to find out with simple search through CVS.
>The only position I know is because of `popen()` etc. in the exec functions 
>which are stdio (posix variants are more complicated), which is the cause 
>for the bug report I mentioned.
>
>At 09:40 07.04.2005, Uwe Schindler wrote:
> > […]
>
>-----
>Uwe Schindler
>thetaphi@php.net - http://www.php.net
>NSAPI SAPI developer
>Bremen, Germany

---

## #15924 — Wez Furlong — 2005-04-09T03:40:55+00:00

URL: https://externals.io/message/15890#15924 · In reply to: #15921

It should probably go into the engine.

--Wez.


> Not sure. Wez or Sara know that part of the code best.
> I'll refrain from applying to the Zend Engine then or should I apply that
> patch anyway? It seems quite harmless either way...
> 
> Andi
> 
> At 04:58 PM 4/8/2005 +0200, Uwe Schindler wrote:
> > […]