Simple garbage collection (really a to-be-freed list) for the sudoers

plugin.  Almost identical to what sudo.c uses.  Currenly only the
environment strings are collected at exit time which is enough to
quiet address sanitizer's leak detector.
This commit is contained in:
Todd C. Miller
2016-01-28 14:53:48 -07:00
parent 7b2fbed45d
commit 21d6fc3d8f
5 changed files with 174 additions and 2 deletions

View File

@@ -259,6 +259,7 @@ plugins/sudoers/defaults.h
plugins/sudoers/editor.c
plugins/sudoers/env.c
plugins/sudoers/find_path.c
plugins/sudoers/gc.c
plugins/sudoers/getdate.c
plugins/sudoers/getdate.y
plugins/sudoers/getspwuid.c

View File

@@ -151,7 +151,7 @@ LIBPARSESUDOERS_OBJS = alias.lo audit.lo base64.lo defaults.lo hexchar.lo \
toke_util.lo
SUDOERS_OBJS = $(AUTH_OBJS) boottime.lo check.lo editor.lo env.lo find_path.lo \
goodpath.lo group_plugin.lo interfaces.lo iolog.lo \
gc.lo goodpath.lo group_plugin.lo interfaces.lo iolog.lo \
iolog_path.lo locale.lo logging.lo logwrap.lo parse.lo \
policy.lo prompt.lo set_perms.lo sudo_nss.lo sudoers.lo \
timestamp.lo @SUDOERS_OBJS@
@@ -666,6 +666,14 @@ fwtk.lo: $(authdir)/fwtk.c $(devdir)/def_data.h $(incdir)/compat/stdbool.h \
$(srcdir)/sudoers.h $(srcdir)/sudoers_debug.h \
$(top_builddir)/config.h $(top_builddir)/pathnames.h
$(LIBTOOL) $(LTFLAGS) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(authdir)/fwtk.c
gc.lo: $(srcdir)/gc.c $(devdir)/def_data.h $(incdir)/compat/stdbool.h \
$(incdir)/sudo_compat.h $(incdir)/sudo_conf.h $(incdir)/sudo_debug.h \
$(incdir)/sudo_fatal.h $(incdir)/sudo_gettext.h $(incdir)/sudo_plugin.h \
$(incdir)/sudo_queue.h $(incdir)/sudo_util.h $(srcdir)/defaults.h \
$(srcdir)/logging.h $(srcdir)/sudo_nss.h $(srcdir)/sudoers.h \
$(srcdir)/sudoers_debug.h $(top_builddir)/config.h \
$(top_builddir)/pathnames.h
$(LIBTOOL) $(LTFLAGS) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(srcdir)/gc.c
getdate.o: $(devdir)/getdate.c $(incdir)/sudo_compat.h $(top_builddir)/config.h
$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(devdir)/getdate.c
getspwuid.lo: $(srcdir)/getspwuid.c $(devdir)/def_data.h \

View File

@@ -1,5 +1,5 @@
/*
* Copyright (c) 2000-2005, 2007-2015
* Copyright (c) 2000-2005, 2007-2016
* Todd C. Miller <Todd.Miller@courtesan.com>
*
* Permission to use, copy, modify, and distribute this software for any
@@ -412,6 +412,8 @@ sudo_setenv2(const char *var, const char *val, bool dupcheck, bool overwrite)
}
if (rval == -1)
free(estring);
else
sudoers_gc_add(GC_PTR, estring);
debug_return_int(rval);
}
@@ -468,6 +470,8 @@ sudo_setenv_nodebug(const char *var, const char *val, int overwrite)
done:
if (rval == -1)
free(estring);
else
sudoers_gc_add(GC_PTR, estring);
return rval;
}
@@ -972,6 +976,7 @@ rebuild_env(void)
free(cp);
goto bad;
}
sudoers_gc_add(GC_PTR, cp);
}
} else {
/*
@@ -1060,6 +1065,7 @@ rebuild_env(void)
free(cp);
goto bad;
}
sudoers_gc_add(GC_PTR, cp);
} else {
CHECK_SETENV2("SUDO_COMMAND", user_cmnd, true, true);
}
@@ -1217,6 +1223,7 @@ read_env_file(const char *path, int overwrite)
memcpy(cp, var, var_len + 1); /* includes '=' */
memcpy(cp + var_len + 1, val, val_len + 1); /* includes NUL */
sudoers_gc_add(GC_PTR, cp);
if (sudo_putenv(cp, true, overwrite) == -1) {
/* XXX - no undo on failure */
rval = false;

146
plugins/sudoers/gc.c Normal file
View File

@@ -0,0 +1,146 @@
/*
* Copyright (c) 2016 Todd C. Miller <Todd.Miller@courtesan.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <config.h>
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include "sudoers.h"
struct sudoers_gc_entry {
SLIST_ENTRY(sudoers_gc_entry) entries;
enum sudoers_gc_types type;
union {
char **vec;
void *ptr;
} u;
};
SLIST_HEAD(sudoers_gc_list, sudoers_gc_entry);
#ifdef NO_LEAKS
static struct sudoers_gc_list sudoers_gc_list =
SLIST_HEAD_INITIALIZER(sudoers_gc_list);
#endif
bool
sudoers_gc_add(enum sudoers_gc_types type, void *v)
{
#ifdef NO_LEAKS
struct sudoers_gc_entry *gc;
debug_decl(sudoers_gc_add, SUDOERS_DEBUG_UTIL)
if (v == NULL)
debug_return_bool(false);
gc = calloc(1, sizeof(*gc));
if (gc == NULL) {
sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
debug_return_bool(false);
}
switch (type) {
case GC_PTR:
gc->u.ptr = v;
break;
case GC_VECTOR:
gc->u.vec = v;
break;
default:
free(gc);
sudo_warnx("unexpected garbage type %d", type);
debug_return_bool(false);
}
gc->type = type;
SLIST_INSERT_HEAD(&sudoers_gc_list, gc, entries);
debug_return_bool(true);
#else
return true;
#endif /* NO_LEAKS */
}
bool
sudoers_gc_remove(enum sudoers_gc_types type, void *v)
{
#ifdef NO_LEAKS
struct sudoers_gc_entry *gc, *prev = NULL;
debug_decl(sudoers_gc_remove, SUDOERS_DEBUG_UTIL)
SLIST_FOREACH(gc, &sudoers_gc_list, entries) {
switch (gc->type) {
case GC_PTR:
if (gc->u.ptr == v)
goto found;
break;
case GC_VECTOR:
if (gc->u.vec == v)
goto found;
break;
default:
sudo_warnx("unexpected garbage type %d in %p", gc->type, gc);
}
prev = gc;
}
return false;
found:
if (prev != NULL)
SLIST_REMOVE_HEAD(&sudoers_gc_list, entries);
else
SLIST_REMOVE_AFTER(prev, entries);
return true;
#else
return false;
#endif /* NO_LEAKS */
}
#ifdef NO_LEAKS
static void
sudoers_gc_run(void)
{
struct sudoers_gc_entry *gc;
char **cur;
debug_decl(sudoers_gc_run, SUDOERS_DEBUG_UTIL)
/* Collect garbage. */
while ((gc = SLIST_FIRST(&sudoers_gc_list))) {
SLIST_REMOVE_HEAD(&sudoers_gc_list, entries);
switch (gc->type) {
case GC_PTR:
free(gc->u.ptr);
free(gc);
break;
case GC_VECTOR:
for (cur = gc->u.vec; *cur != NULL; cur++)
free(*cur);
free(gc->u.vec);
free(gc);
break;
default:
sudo_warnx("unexpected garbage type %d", gc->type);
}
}
debug_return;
}
#endif /* NO_LEAKS */
void
sudoers_gc_init(void)
{
#ifdef NO_LEAKS
atexit(sudoers_gc_run);
#endif
}

View File

@@ -377,4 +377,14 @@ extern const char *path_plugin_dir;
char *resolve_editor(const char *ed, size_t edlen, int nfiles, char **files,
int *argc_out, char ***argv_out, char * const *whitelist);
/* gc.c */
enum sudoers_gc_types {
GC_UNKNOWN,
GC_VECTOR,
GC_PTR
};
bool sudoers_gc_add(enum sudoers_gc_types type, void *ptr);
bool sudoers_gc_remove(enum sudoers_gc_types type, void *ptr);
void sudoers_gc_init(void);
#endif /* SUDOERS_SUDOERS_H */