From 92cc3e7f76a545a2cd4828576971f1eea83f4e68 Mon Sep 17 00:00:00 2001 From: Francis Deslauriers Date: Wed, 17 Mar 2021 10:40:56 -0400 Subject: [PATCH] Fix: kretprobe: null ptr deref on session destroy The `filter_bytecode_runtime_head` list is currently not initialized for the return event of the kretprobe. This caused a kernel null ptr dereference when destroying a session. It can reproduced with the following commands: lttng create lttng enable-event -k --function=lttng_test_filter_event_write my_event lttng start lttng stop lttng destroy Signed-off-by: Francis Deslauriers Signed-off-by: Mathieu Desnoyers Change-Id: I1162ce8b10dd7237a26331531f048346b984eee7 --- lttng-events.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/lttng-events.c b/lttng-events.c index 984bd341..3450fa40 100644 --- a/lttng-events.c +++ b/lttng-events.c @@ -704,6 +704,8 @@ struct lttng_event *_lttng_event_create(struct lttng_channel *chan, event_return->enabled = 0; event_return->registered = 1; event_return->instrumentation = itype; + INIT_LIST_HEAD(&event_return->bytecode_runtime_head); + INIT_LIST_HEAD(&event_return->enablers_ref_head); /* * Populate lttng_event structure before kretprobe registration. */ -- 2.34.1