BUG/MEDIUM: cli/shutdown sessions: make it thread-safe

There's no locking around the lookup of a stream nor its shutdown
when issuing "shutdown sessions" over the CLI so the risk of crashing
the process is particularly high.

Let's use a thread_isolate() there which is suitable for this task, and
there are not that many alternatives.

This must be backported to 1.8.

(cherry picked from commit 3f5dd2945ccbed6b4baf23a453e9d1d071a2d835)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>

diff --git a/src/stream.c b/src/stream.c
index b2e9c0e..a2feea1 100644 (file)
--- a/src/stream.c
+++ b/src/stream.c
@@ -3410,17 +3410,22 @@ static int cli_parse_shutdown_session(char **args, char *payload, struct appctx
 
        ptr = (void *)strtoul(args[2], NULL, 0);
 
+       thread_isolate();
+
        /* first, look for the requested stream in the stream table */
        list_for_each_entry(strm, &streams, list) {
-               if (strm == ptr)
+               if (strm == ptr) {
+                       stream_shutdown(strm, SF_ERR_KILLED);
                        break;
+               }
        }
 
+       thread_release();
+
        /* do we have the stream ? */
        if (strm != ptr)
                return cli_err(appctx, "No such session (use 'show sess').\n");
 
-       stream_shutdown(strm, SF_ERR_KILLED);
        return 1;
 }