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Date:      Mon, 21 May 2001 09:29:47 -0700 (PDT)
From:      thierry@herbelot.com
To:        freebsd-gnats-submit@FreeBSD.org
Subject:   bin/27506: memory leak in libfetch
Message-ID:  <200105211629.f4LGTlV51311@freefall.freebsd.org>

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>Number:         27506
>Category:       bin
>Synopsis:       memory leak in libfetch
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon May 21 09:30:01 PDT 2001
>Closed-Date:
>Last-Modified:
>Originator:     thierry herbelot
>Release:        4.3-Release
>Organization:
>Environment:
FreeBSD pc-bsd60.XXXX 4.3-RELEASE FreeBSD 4.3-RELEASE #11: 
Tue Apr 24 19:14:23 CEST 2001
herbelot@pc-bsd60.XXXXX:/usr/obj/usr/src/sys/station  i386
>Description:
I'm using libfetch for automated file transfers from a program (via ftp).

The program is running for long periods of time, and seems to be 
leaking memory (at least it's SIZE in top(1) just grows and grows - 
the swap is also increasingly used).

As there is no dynamically allocated memory in my program, one suspect 
could be libfetch(3).

Indeed, there are 5 calls to malloc(3) in the source code of the lib :
- in common.c, line 263, which should not cause a leak as the pointer 
is stored in buf, which is later saved,
- in common.c, line 362, in a function which is not used in my app 
(the file name is known)
- in fetch.c, line 377, in a function which is used only for http/https
transfers, thus not in my app,
- in http.c, line 517, in a function which is used only for http/https 
transfers, thus not in my app,
- finally in ftp.c, line 434, in a suspicious manner : the "io" 
variable is located on the stack, thus visible only from this function,
gets a pointer to a newly allocated ftpio struct and disappears after 
_ftp_setup() returns.

The comparison between usr.bin/compress/zopen.c:zclose() and 
lib/libfetch/ftp.c:_ftp_close() shows a missing free(cookie) at the 
end of the function.

>How-To-Repeat:
just having a constantly running program fetching repeated files
using libfetch (the fetch(1) program is a bad example, as it runs for
a very short period of time - my program runs for extended periods of
time, like one week, and fetches many files each second)
>Fix:
the following patch seems to cure the memory leak :
-----------------------------------------
--- ftp.c.ori	Sat Apr  7 19:30:48 2001
+++ ftp.c	Mon May 21 15:26:42 2001
@@ -422,7 +422,9 @@
 	io->err = 0;
     close(io->csd);
     io->csd = -1;
-    return io->err ? -1 : 0;
+    r = io->err ? -1 : 0;
+    free(io);
+    return (r);
 }
 
 static FILE *
-----------------------------------------


>Release-Note:
>Audit-Trail:
>Unformatted:

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