misc/55181: Memory leak in vfprintf()
Ryan T.Dean
rtdean at cytherianage.net
Sat Aug 2 02:20:07 PDT 2003
>Number: 55181
>Category: misc
>Synopsis: Memory leak in vfprintf()
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Sat Aug 02 02:20:04 PDT 2003
>Closed-Date:
>Last-Modified:
>Originator: Ryan T. Dean
>Release: FreeBSD 5.1-CURRENT i386
>Organization:
<organization of PR author (multiple lines)>
>Environment:
Under -CURRENT:
System: FreeBSD glyph.cytherianage.net 5.1-CURRENT FreeBSD 5.1-CURRENT #0: Wed Jul 30 16:43:52 EDT 2003 root at glyph.cytherianage.net:/usr/obj/usr/src/sys/GLYPH i386
Under -STABLE:
System: FreeBSD tonberi.cytherianage.net 4.8-STABLE FreeBSD 4.8-STABLE #2: Tue Jul 29 20:46:05 EDT 2003 root at tonberi.cytherianage.net:/usr/obj/usr/src/sys/TONBERI i386
>Description:
A 4096-byte memory leak appears to exist in the FreeBSD libc, involving the stdio functions. More specifically, the memory is allocated on a call to printf(), which in turn calls vfprintf(). The memory is subsequently never freed. I have observed this behaviour on -CURRENT as of the 30th of July, and on -STABLE as of the 29th of July. It was also reported, indirectly, on the FreeBSD ports mailing list on the 21st of July. It has been observed using dmalloc (devel/dmalloc; dmalloc.com) and NJAMD (sourceforge.net/projects/njamd).
I suspect this problem may also occur in vsprintf() as well.
I have CC'd rwatson at freebsd.org because a 'make -V MAINTAINER' in src/lib/libc returned his email address. I apologize if this was / is in error.
>How-To-Repeat:
Compile any program that uses vfprintf, and observe it through a memory debugger. On the first call to vfprintf(), a 4096-byte chunk of memory will be allocated. It will never be freed.
>Fix:
>Release-Note:
>Audit-Trail:
>Unformatted:
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