[tor-commits] [tor/master] added openat parameter filter

[nickm at torproject.org]

commit 8022def6f05bf40e1c6e0fd15d77ed0ecf5c3406
Author: Cristian Toader <cristian.matei.toader at gmail.com>
Date:   Mon Jul 29 16:30:39 2013 +0300

    added openat parameter filter
---
 src/common/sandbox.c |   19 ++++++++++++++-----
 src/common/sandbox.h |    4 +++-
 src/common/util.c    |    4 +++-
 src/or/main.c        |    2 ++
 4 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/src/common/sandbox.c b/src/common/sandbox.c
index 2e8467d..efadeca 100644
--- a/src/common/sandbox.c
+++ b/src/common/sandbox.c
@@ -117,7 +117,6 @@ static int filter_nopar_gen[] = {
     SCMP_SYS(mprotect),
     SCMP_SYS(mremap),
     SCMP_SYS(munmap),
-    SCMP_SYS(openat),
     SCMP_SYS(poll),
     SCMP_SYS(prctl),
     SCMP_SYS(read),
@@ -158,7 +157,7 @@ static int filter_nopar_gen[] = {
 };
 
 const char*
-sandbox_intern_string(char *param)
+sandbox_intern_string(const char *param)
 {
   int i, filter_size;
   sandbox_cfg_t *elem;
@@ -228,15 +227,25 @@ prot_strdup(char* str)
 int
 sandbox_cfg_allow_open_filename(sandbox_cfg_t **cfg, char *file)
 {
-  sandbox_cfg_t *elem = (sandbox_cfg_t*) malloc(sizeof(sandbox_cfg_t));
+  sandbox_cfg_t *elem = NULL;
+  intptr_t prot_str = (intptr_t) prot_strdup((char*) file);
 
+  elem = (sandbox_cfg_t*) malloc(sizeof(sandbox_cfg_t));
   elem->syscall = SCMP_SYS(open);
   elem->pindex = 0;
   elem->ptype = PARAM_PTR;
-  elem->param = (intptr_t) prot_strdup((char*) file);
+  elem->param = prot_str;
   elem->prot = 1;
+  elem->next = filter_dynamic;
+  filter_dynamic = elem;
 
-  // fifo
+  // also allow openat
+  elem = (sandbox_cfg_t*) malloc(sizeof(sandbox_cfg_t));
+  elem->syscall = SCMP_SYS(openat);
+  elem->pindex = 1;
+  elem->ptype = PARAM_PTR;
+  elem->param = prot_str;
+  elem->prot = 1;
   elem->next = filter_dynamic;
   filter_dynamic = elem;
 
diff --git a/src/common/sandbox.h b/src/common/sandbox.h
index 9acf8c4..104d832 100644
--- a/src/common/sandbox.h
+++ b/src/common/sandbox.h
@@ -29,7 +29,9 @@
  */
 #ifdef __linux__
 
+#ifndef __USE_GNU
 #define __USE_GNU
+#endif
 #include <sys/ucontext.h>
 
 #define MAX_PARAM_LEN 64
@@ -80,7 +82,7 @@ typedef struct pfd_elem sandbox_cfg_t;
 
 void sandbox_set_debugging_fd(int fd);
 int tor_global_sandbox(void);
-const char* sandbox_intern_string(char *param);
+const char* sandbox_intern_string(const char *param);
 
 sandbox_cfg_t * sandbox_cfg_new();
 int sandbox_cfg_allow_open_filename(sandbox_cfg_t **cfg, char *file);
diff --git a/src/common/util.c b/src/common/util.c
index 651554e..75462b6 100644
--- a/src/common/util.c
+++ b/src/common/util.c
@@ -24,6 +24,7 @@
 #include "torint.h"
 #include "container.h"
 #include "address.h"
+#include "../common/sandbox.h"
 
 #ifdef _WIN32
 #include <io.h>
@@ -3042,6 +3043,7 @@ smartlist_t *
 tor_listdir(const char *dirname)
 {
   smartlist_t *result;
+  const char *prot_dname = sandbox_intern_string(dirname);
 #ifdef _WIN32
   char *pattern=NULL;
   TCHAR tpattern[MAX_PATH] = {0};
@@ -3085,7 +3087,7 @@ tor_listdir(const char *dirname)
 #else
   DIR *d;
   struct dirent *de;
-  if (!(d = opendir(dirname)))
+  if (!(d = opendir(prot_dname)))
     return NULL;
 
   result = smartlist_new();
diff --git a/src/or/main.c b/src/or/main.c
index 269d3fd..d50f239 100644
--- a/src/or/main.c
+++ b/src/or/main.c
@@ -2645,6 +2645,8 @@ sandbox_init_filter()
   sandbox_cfg_t *cfg = sandbox_cfg_new();
 
   sandbox_cfg_allow_open_filename(&cfg,
+      get_datadir_fname("cached-status"));
+  sandbox_cfg_allow_open_filename(&cfg,
       get_datadir_fname("cached-certs"));
   sandbox_cfg_allow_open_filename(&cfg,
       get_datadir_fname("cached-consensus"));