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* src/su.c: Also drop the controlling terminal when PAM is not

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used.
	* src/su.c: Remove run_shell().
This commit is contained in:
nekral-guest 2011-06-13 18:27:40 +00:00
parent e9045e9f55
commit 1340beed16
2 changed files with 58 additions and 44 deletions
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3
ChangeLog
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@ -5,6 +5,9 @@
prepare_pam_close_session() is now executed before the creation of
the pam session and before the UID is changed. This allows to
close the session as root.
* src/su.c: Also drop the controlling terminal when PAM is not
used.
* src/su.c: Remove run_shell().
2011-06-12 Nicolas François <nicolas.francois@centraliens.net>

99
src/su.c
View File

@ -61,6 +61,13 @@
#include <signal.h>
#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
#ifndef USE_PAM
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#endif /* !USE_PAM */
#include "prototypes.h"
#include "defines.h"
#include "pwauth.h"
@ -119,6 +126,7 @@ static void execve_shell (const char *shellstr,
char *const envp[]);
#ifdef USE_PAM
static RETSIGTYPE kill_child (int unused(s));
static void prepare_pam_close_session (void);
#else /* !USE_PAM */
static RETSIGTYPE die (int);
static bool iswheel (const char *);
@ -258,9 +266,10 @@ static void catch_signals (int sig)
}
/*
* Create a session and fork.
* Only the child returns. The parent will wait for the child to terminate
* and exit.
* prepare_pam_close_session - Fork and wait for the child to close the session
*
* Only the child returns. The parent will wait for the child to
* terminate and exit.
*/
static void prepare_pam_close_session (void)
{
@ -385,35 +394,11 @@ static void prepare_pam_close_session (void)
: WTERMSIG (status) + 128);
/* Only the child returns. See above. */
}
static void run_shell (const char *shellstr, char *args[], bool doshell,
char *const envp[])
{
/*
* PAM_DATA_SILENT is not supported by some modules, and
* there is no strong need to clean up the process space's
* memory since we will either call exec or exit.
pam_end (pamh, PAM_SUCCESS | PAM_DATA_SILENT);
*/
if (doshell) {
(void) shell (shellstr, (char *) args[0], envp);
} else {
/* There is no need for a controlling terminal.
* This avoids the callee to inject commands on
* the caller's tty. */
(void) setsid ();
execve_shell (shellstr, (char **) args, envp);
}
exit (errno == ENOENT ? E_CMD_NOTFOUND : E_CMD_NOEXEC);
}
#endif /* USE_PAM */
/*
* usage - print command line syntax and exit
*/
*/
static void usage (int status)
{
fputs (_("Usage: su [options] [LOGIN]\n"
@ -1049,6 +1034,40 @@ int main (int argc, char **argv)
set_environment (pw);
if (!doshell) {
/* There is no need for a controlling terminal.
* This avoids the callee to inject commands on
* the caller's tty. */
int err = -1;
#ifdef USE_PAM
/* When PAM is used, we are on the child */
err = setsid ();
#else
/* Otherwise, we cannot use setsid */
int fd = open ("/dev/tty", O_RDWR);
if (fd >= 0) {
err = ioctl (fd, TIOCNOTTY, (char *) 0);
(void) close (fd);
}
#endif /* USE_PAM */
if (-1 == err) {
(void) fprintf (stderr,
_("%s: Cannot drop the controlling terminal\n"),
Prog);
exit (1);
}
}
/*
* PAM_DATA_SILENT is not supported by some modules, and
* there is no strong need to clean up the process space's
* memory since we will either call exec or exit.
pam_end (pamh, PAM_SUCCESS | PAM_DATA_SILENT);
*/
endpwent ();
endspent ();
/*
@ -1081,6 +1100,7 @@ int main (int argc, char **argv)
}
if (!doshell) {
int err;
/* Position argv to the remaining arguments */
argv += optind;
if (NULL != command) {
@ -1093,24 +1113,15 @@ int main (int argc, char **argv)
* with the rest of the command line included.
*/
argv[-1] = cp;
#ifndef USE_PAM
execve_shell (shellstr, &argv[-1], environ);
err = errno;
(void) fputs (_("No shell\n"), stderr);
SYSLOG ((LOG_WARN, "Cannot execute %s", shellstr));
closelog ();
exit ((ENOENT == err) ? E_CMD_NOTFOUND : E_CMD_NOEXEC);
#else
run_shell (shellstr, &argv[-1], false, environ); /* no return */
#endif
(void) fprintf (stderr,
_("Cannot execute %s\n"), shellstr);
errno = err;
} else {
(void) shell (shellstr, cp, environ);
}
#ifndef USE_PAM
err = shell (shellstr, cp, environ);
exit ((ENOENT == err) ? E_CMD_NOTFOUND : E_CMD_NOEXEC);
#else
run_shell (shellstr, &cp, true, environ);
#endif
/* NOT REACHED */
exit (1);
return (errno == ENOENT ? E_CMD_NOTFOUND : E_CMD_NOEXEC);
}