From d8ddfcf4e0f7342f362d587a2789d69773a20f1c Mon Sep 17 00:00:00 2001

From: Jakub Filak <jfilak@redhat.com>

Date: Tue, 21 May 2019 14:56:47 +0000

Subject: [PATCH] daemon: avoid infinite crash loops

Export an environment variable as a mark for abrtd (abrt-server) to

identify processes directly involved in ABRT post-mortem processing.

We must not run post-mortem EVENTs on problem directories caused by ABRT

itself because we could create an infinite loop.

There are to ways how to handle such directories:

    * in non-debug mode: log a short message and remove them without

      other actions - we must not leave them in the dump location by

      default because the dump location would be growing

    * in debug mode: log a more verbose message and leave them as they

      are - we don need to have worries about the dump location growing

      because someone intentionally enable the debug mode

Related: rhbz#1246539

cherry-picked from https://github.com/abrt/abrt/commit/68e0efaa36f6d4aabfd8ecf71bf0c22adfc72b03

Related: rhbz#1688368

Signed-off-by: Martin Kutlak <mkutlak@redhat.com>

---

 src/daemon/abrt-server.c | 54 ++++++++++++++++++++++++++++++++++++++--

 1 file changed, 52 insertions(+), 2 deletions(-)

diff --git a/src/daemon/abrt-server.c b/src/daemon/abrt-server.c

index e1dfc4af..60eb9b66 100644

--- a/src/daemon/abrt-server.c

+++ b/src/daemon/abrt-server.c

@@ -28,6 +28,7 @@

 /* We exit after this many seconds */

 #define TIMEOUT 10

+#define ABRT_SERVER_EVENT_ENV "ABRT_SERVER_PID"

 /*

 Unix socket in ABRT daemon for creating new dump directories.

@@ -206,10 +207,11 @@ static pid_t spawn_event_handler_child(const char *dump_dir_name, const char *ev

     int flags = EXECFLG_INPUT_NUL | EXECFLG_OUTPUT | EXECFLG_QUIET | EXECFLG_ERR2OUT;

     VERB1 flags &= ~EXECFLG_QUIET;

-    char *env_vec[2];

+    char *env_vec[3];

     /* Intercept ASK_* messages in Client API -> don't wait for user response */

     env_vec[0] = xstrdup("REPORT_CLIENT_NONINTERACTIVE=1");

-    env_vec[1] = NULL;

+    env_vec[1] = xasprintf("%s=%d", ABRT_SERVER_EVENT_ENV, getpid());

+    env_vec[2] = NULL;

     pid_t child = fork_execv_on_steroids(flags, args, pipeout,

                                          env_vec, /*dir:*/ NULL,

@@ -219,6 +221,23 @@ static pid_t spawn_event_handler_child(const char *dump_dir_name, const char *ev

     return child;

 }

+static int problem_dump_dir_was_provoked_by_abrt_event(struct dump_dir *dd, char  **provoker)

+{

+    char *env_var = NULL;

+    const int r = dd_get_env_variable(dd, ABRT_SERVER_EVENT_ENV, &env_var);

+

+    /* Dump directory doesn't contain the environ file */

+    if (r == -ENOENT)

+        return 0;

+

+    if (provoker != NULL)

+        *provoker = env_var;

+    else

+        free(env_var);

+

+    return env_var != NULL;

+}

+

 static gboolean emit_new_problem_signal(gpointer data)

 {

     struct waiting_context *context = (struct waiting_context *)data;

@@ -254,6 +273,37 @@ static int run_post_create(const char *dirname)

     if (g_settings_privatereports)

     {

         struct dump_dir *dd = dd_opendir(dirname, DD_OPEN_READONLY);

+

+        char *provoker = NULL;

+        const bool event_dir = dd && problem_dump_dir_was_provoked_by_abrt_event(dd, &provoker);

+        if (event_dir)

+        {

+            if (g_settings_debug_level == 0)

+            {

+                error_msg("Removing problem provoked by ABRT(pid:%s): '%s'", provoker, dirname);

+                dd_delete(dd);

+            }

+            else

+            {

+                char *dumpdir = NULL;

+                char *event   = NULL;

+                char *reason  = NULL;

+                char *cmdline = NULL;

+

+                /* Ignore errors */

+                dd_get_env_variable(dd, "DUMP_DIR", &dumpdir);

+                dd_get_env_variable(dd, "EVENT",    &event);

+                reason  = dd_load_text(dd, FILENAME_REASON);

+                cmdline = dd_load_text(dd, FILENAME_CMDLINE);

+

+                error_msg("ABRT_SERVER_PID=%s;DUMP_DIR='%s';EVENT='%s';REASON='%s';CMDLINE='%s'",

+                           provoker, dumpdir, event, reason, cmdline);

+            }

+

+            free(provoker);

+            return 400;

+        }

+

         const bool complete = dd && problem_dump_dir_is_complete(dd);

         dd_close(dd);

         if (complete)

-- 

2.21.0