From ab036a634622df4e3657f3936ba688e2c0d12c50 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Mon, 13 Jul 2020 14:59:33 -0400 Subject: [PATCH] Fix: Lock metadata cache on session destroy commit 92143b2c5656 ("Fix: metadata stream leak, missing list removal and locking") missed taking a lock protecting the metadata stream list iteration on session destroy. This opens a race window between iteration and item removal/free which triggers kernel OOPS. Signed-off-by: Mathieu Desnoyers --- src/lttng-events.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/src/lttng-events.c b/src/lttng-events.c index 11b0ed53..62f8e054 100644 --- a/src/lttng-events.c +++ b/src/lttng-events.c @@ -214,8 +214,10 @@ void lttng_session_destroy(struct lttng_session *session) BUG_ON(chan->channel_type == METADATA_CHANNEL); _lttng_channel_destroy(chan); } + mutex_lock(&session->metadata_cache->lock); list_for_each_entry(metadata_stream, &session->metadata_cache->metadata_stream, list) _lttng_metadata_channel_hangup(metadata_stream); + mutex_unlock(&session->metadata_cache->lock); lttng_id_tracker_destroy(&session->pid_tracker, false); lttng_id_tracker_destroy(&session->vpid_tracker, false); lttng_id_tracker_destroy(&session->uid_tracker, false); -- 2.34.1