On exec, honor additional_gids from the process spec, not the container definition

The code was using the process defined in the container definition to find additional_gids,
not the one passed on the command line or created by default.

Fixes #644

Signed-off-by: Owen W. Taylor <otaylor@fishsoup.net>

Author: owtaylor

src/libcrun/container.c

@@ -3177,7 +3177,7 @@ libcrun_container_exec (libcrun_context_t *context, const char *id, runtime_spec
           close_and_reset (&seccomp_receiver_fd);
         }
 
-      ret = libcrun_container_setgroups (container, err);
+      ret = libcrun_container_setgroups (container, process, err);
       if (UNLIKELY (ret < 0))
         return ret;
 

src/libcrun/linux.c

@@ -2090,18 +2090,19 @@ can_setgroups (libcrun_container_t *container, libcrun_error_t *err)
 }
 
 int
-libcrun_container_setgroups (libcrun_container_t *container, libcrun_error_t *err)
+libcrun_container_setgroups (libcrun_container_t *container,
+                             runtime_spec_schema_config_schema_process *process,
+                             libcrun_error_t *err)
 {
-  runtime_spec_schema_config_schema *def = container->container_def;
   gid_t *additional_gids = NULL;
   size_t additional_gids_len = 0;
   int can_do_setgroups;
   int ret;
 
-  if (def->process != NULL && def->process->user != NULL)
+  if (process != NULL && process->user != NULL)
     {
-      additional_gids = def->process->user->additional_gids;
-      additional_gids_len = def->process->user->additional_gids_len;
+      additional_gids = process->user->additional_gids;
+      additional_gids_len = process->user->additional_gids_len;
     }
 
   can_do_setgroups = can_setgroups (container, err);
@@ -3217,7 +3218,7 @@ init_container (libcrun_container_t *container, int sync_socket_container, struc
         return ret;
     }
 
-  ret = libcrun_container_setgroups (container, err);
+  ret = libcrun_container_setgroups (container, container->container_def->process, err);
   if (UNLIKELY (ret < 0))
     return ret;
 

src/libcrun/linux.h

@@ -68,7 +68,9 @@ int libcrun_container_restore_linux (libcrun_container_status_t *status, libcrun
 
 int libcrun_find_namespace (const char *name);
 char *libcrun_get_external_descriptors (libcrun_container_t *container);
-int libcrun_container_setgroups (libcrun_container_t *container, libcrun_error_t *err);
+int libcrun_container_setgroups (libcrun_container_t *container,
+                                 runtime_spec_schema_config_schema_process *process,
+                                 libcrun_error_t *err);
 int libcrun_kill_linux (libcrun_container_status_t *status, int signal, libcrun_error_t *err);
 int libcrun_create_final_userns (libcrun_container_t *container, libcrun_error_t *err);
 #endif

tests/init.c

@@ -207,6 +207,19 @@ int main (int argc, char **argv)
       exit (0);
     }
 
+  if (strcmp (argv[1], "groups") == 0)
+    {
+      gid_t groups[10];
+      int max_groups = sizeof(groups) / sizeof(groups[0]);
+      int n_groups, i;
+      n_groups = getgroups(max_groups, groups);
+      fputs("GROUPS=[", stdout);
+      for (i = 0; i < n_groups; i++)
+        printf("%s%d", i == 0 ? "" : " ", groups[i]);
+      fputs("]\n", stdout);
+      exit (0);
+    }
+
   if (strcmp (argv[1], "cat") == 0)
     {
       if (argc < 3)

tests/test_exec.py

@@ -21,6 +21,7 @@
 import os
 import shutil
 import sys
+import tempfile
 from tests_utils import *
 
 def test_exec():
@@ -62,11 +63,50 @@ def test_exec_not_exists():
 
 def test_exec_detach_not_exists():
     return test_exec_not_exists_helper(False)
-    
+
+def test_exec_additional_gids():
+    conf = base_config()
+    conf['process']['args'] = ['/init', 'pause']
+    add_all_namespaces(conf)
+    cid = None
+    tempdir = tempfile.mkdtemp()
+    try:
+        _, cid = run_and_get_output(conf, command='run', detach=True)
+
+        process_file = os.path.join(tempdir, "process.json")
+        with open(process_file, "w") as f:
+            json.dump({
+	        "user": {
+	            "uid": 0,
+	            "gid": 0,
+                    "additionalGids": [432]
+	        },
+                "terminal": False,
+	        "args": [
+                    "/init",
+                    "groups"
+	        ],
+	        "env": [
+	            "PATH=/bin",
+	            "TERM=xterm"
+	        ],
+	        "cwd": "/",
+	        "noNewPrivileges": True
+            }, f)
+        out = run_crun_command(["exec", "--process", process_file, cid])
+        if "432" not in out:
+            return -1
+    finally:
+        if cid is not None:
+            run_crun_command(["delete", "-f", cid])
+        shutil.rmtree(tempdir)
+    return 0
+
 all_tests = {
     "exec" : test_exec,
     "exec-not-exists" : test_exec_not_exists,
     "exec-detach-not-exists" : test_exec_detach_not_exists,
+    "exec-detach-additional-gids" : test_exec_additional_gids,
 }
 
 if __name__ == "__main__":