tracing: Fix allocation of printing set_event file content

From: Steven Rostedt <rostedt@goodmis.org>

The adding of cached events for modules not loaded yet required a
descriptor to separate the iteration of events with the iteration of
cached events for a module. But the allocation used the size of the
pointer and not the size of the contents to allocate its data and caused a
slab-out-of-bounds.

Reported-by: Sasha Levin <sashal@kernel.org>
Closes: https://lore.kernel.org/all/Z4_OHKESRSiJcr-b@lappy/
Fixes: b355247df104e ("tracing: Cache ":mod:" events for modules not loaded yet")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
 kernel/trace/trace_events.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 51c5014877e8..5217dcddcb4c 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c

@@ -1588,7 +1588,7 @@ static void *s_start(struct seq_file *m, loff_t *pos)
 	struct set_event_iter *iter;
 	loff_t l;
 
-	iter = kzalloc(sizeof(iter), GFP_KERNEL);
+	iter = kzalloc(sizeof(*iter), GFP_KERNEL);
 	if (!iter)
 		return NULL;
 

-- 
2.45.2