Date: Thu, 25 Dec 2003 10:20:18 -0800 (PST) From: Friedemann Becker <zxmxy33@mail.uni-tuebingen.de> To: freebsd-bugs@FreeBSD.org Subject: Re: bin/2442: setusershell()/endusershell() missing Message-ID: <200312251820.hBPIKIvq096235@freefall.freebsd.org>
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The following reply was made to PR bin/2442; it has been noted by GNATS.
From: Friedemann Becker <zxmxy33@mail.uni-tuebingen.de>
To: freebsd-gnats-submit@FreeBSD.org, charnier@xp11.frmug.org
Cc:
Subject: Re: bin/2442: setusershell()/endusershell() missing
Date: Thu, 25 Dec 2003 19:15:24 +0100
This is was i found about the xxxusershell issue:
in src/lib/libc/gen/getusershell.c a stringlist is used to store the
/etc/shells entries.
in setusershell(), or getusershell() when called for the first time, the
memory for the string list is allocated (see stringlist.c).
subsequent calls to getusershell() just return the next entry in the
list, one after one.
endusershell() deallocates the memory.
now, in the patches, XXXusershell() is only used once in each case, so
it doesn't matter, if setusershell() is called or not. this only becomes
a problem, if eventually someone decides to use these functions more
than once per process.
a missing call to endusershell() is not a problem, the memory is free'd
at the next call to setusershell() or process termination.
someone should decide, what to do here. i have reviewed each of the
patches, in case someone wants to apply them.
ftpd.c:
the patch for ftpd still applies and is correct
--- /usr/src/libexec/ftpd/ftpd.c Thu Dec 11 19:07:26 2003
+++ /home/lucius/usr.src/libexec/ftpd/ftpd.c Thu Dec 25 18:02:57 2003
@@ -1015,6 +1015,7 @@
if ((pw = sgetpwnam(name))) {
if ((shell = pw->pw_shell) == NULL || *shell == 0)
shell = _PATH_BSHELL;
+ setusershell();
while ((cp = getusershell()) != NULL)
if (strcmp(cp, shell) == 0)
break;
user.c:
this one still applies, is correct, but different path
note: the result has not to be strdup'ed, only the pointer is tested ==NULL,
the pointer-address isn't affected by free (called in endusershell()).
--- /usr/src/usr.sbin/sysinstall/user.c Thu Jul 5 11:51:09 2001
+++ /home/lucius/usr.src/usr.sbin/sysinstall/user.c Thu Dec 25
18:44:36 2003
@@ -426,6 +426,7 @@
return 0;
}
if (strlen(shell) > 0) {
+ setusershell();
while((cp = getusershell()) != NULL)
if (strcmp(cp, shell) == 0)
break;
util.c:
this patch had to be corrected as described in the audit-trail. now working
--- /usr/src/usr.bin/chpass/util.c Sun Jun 30 07:21:15 2002
+++ /home/lucius/usr.src/usr.bin/chpass/util.c Thu Dec 25 18:14:19 2003
@@ -142,15 +142,21 @@
char *
ok_shell(char *name)
{
- char *p, *sh;
+ char *p, *sh, *ret;
setusershell();
while ((sh = getusershell())) {
- if (!strcmp(name, sh))
+ if (!strcmp(name, sh)) {
+ endusershell();
return (name);
+ }
/* allow just shell name, but use "real" path */
- if ((p = strrchr(sh, '/')) && strcmp(name, p + 1) == 0)
- return (sh);
+ if ((p = strrchr(sh, '/')) && strcmp(name, p + 1) == 0) {
+ ret = strdup(sh);
+ endusershell();
+ return (ret);
+ }
}
+ endusershell();
return (NULL);
}
su.c: this patch is obsolete - {set,get,end}usershell is called
correctly (at least in -current)
pw_scan:
here the curly braces were patched away (the 'for' line),
this was corrected below
--- /usr/src/lib/libc/gen/pw_scan.c Fri Oct 11 13:35:30 2002
+++ /home/lucius/usr.src/lib/libc/gen/pw_scan.c Thu Dec 25 18:29:28 2003
@@ -180,7 +180,7 @@
goto fmt;
p = pw->pw_shell;
- if (root && *p) /* empty == /bin/sh */
+ if (root && *p) { /* empty == /bin/sh */
for (setusershell();;) {
if (!(sh = getusershell())) {
if (flags & _PWSCAN_WARN)
@@ -190,6 +190,8 @@
if (!strcmp(p, sh))
break;
}
+ endusershell();
+ }
if (p[0])
pw->pw_fields |= _PWF_SHELL;
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