Date: Sun, 27 Oct 1996 22:11:04 -0500 (EST) From: dmaddox@scsn.net To: FreeBSD-gnats-submit@freebsd.org Subject: bin/1909: 'last' coredumps if MALLOC_OPTIONS include 'J' Message-ID: <199610280311.WAA16917@rhiannon.scsn.net> Resent-Message-ID: <199610280600.WAA02007@freefall.freebsd.org>
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>Number: 1909
>Category: bin
>Synopsis: 'last' coredumps if MALLOC_OPTIONS include 'J'
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: freebsd-bugs
>State: open
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Sun Oct 27 22:00:02 PST 1996
>Last-Modified:
>Originator: Donald J. Maddox
>Organization:
None
>Release: FreeBSD 2.2-CURRENT i386
>Environment:
FreeBSD rhiannon.scsn.net 2.2-CURRENT FreeBSD 2.2-CURRENT #0: Fri Oct 25 23:10:41 EDT 1996 root@rhiannon.scsn.net:/usr/src/sys/compile/RHIANNON i386
>Description:
'last' coredumps when MALLOC_OPTIONS include 'J'.
The problem seems to be here in /usr/src/usr.bin/last/last.c, lines 192-197:
if (bp->ut_line[0] == '~' && !bp->ut_line[1]) {
/* everybody just logged out */
for (tt = ttylist.lh_first; tt; tt = tt->list.le_next) {
LIST_REMOVE(tt, list);
free(tt);
}
The first time this loop iterates, tt is freed; however, when MALLOC_OPTIONS includes
'J', this causes the pointer to be overwritten with junk, so the second iteration
fails.
>How-To-Repeat:
#ln -sf AJ /etc/malloc.conf
#last
>Fix:
I'm not certain what the best fix is, so I'll leave it to the experts... :-)
>Audit-Trail:
>Unformatted:
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