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.

diff --git a/MANIFEST b/MANIFEST
index a27e2c76a3be2b615e35746e884f55ba8a2afe9c..1e82b5130897c3c37fc063e1cf0997f1dd3039b1 100644 (file)
--- a/MANIFEST
+++ b/MANIFEST
@@ -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

diff --git a/plugins/sudoers/Makefile.in b/plugins/sudoers/Makefile.in
index 04aba2e1d6d363ed1a300f318db0572db8329583..17cdbc0491ab7315dabc548c6f7737f2557af656 100644 (file)
--- a/plugins/sudoers/Makefile.in
+++ b/plugins/sudoers/Makefile.in
@@ -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 \

diff --git a/plugins/sudoers/env.c b/plugins/sudoers/env.c
index a50ac813230769c98c7c329e4fabcd899c1bdb3e..b0097f2412d8b90a3894a44439ca7bc52d625048 100644 (file)
--- a/plugins/sudoers/env.c
+++ b/plugins/sudoers/env.c
@@ -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;

diff --git a/plugins/sudoers/gc.c b/plugins/sudoers/gc.c
new file mode 100644 (file)
index 0000000..eeb8279
--- /dev/null
+++ b/plugins/sudoers/gc.c
@@ -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
+}

diff --git a/plugins/sudoers/sudoers.h b/plugins/sudoers/sudoers.h
index 6d4769688547fc68cdb61ae64fa46b259a6b4167..7fda0505099942f275d2756ba6978c0ecf75d3ce 100644 (file)
--- a/plugins/sudoers/sudoers.h
+++ b/plugins/sudoers/sudoers.h
@@ -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 */