tracing: Free module_delta on freeing of persistent ring buffer

If a persistent ring buffer is created, a "module_delta" array is also
allocated to hold the module deltas of loaded modules that match modules
in the scratch area. If this buffer gets freed, the module_delta array is
not freed and causes a memory leak.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20250401124525.1f9ac02a@gandalf.local.home
Fixes: 35a380ddbc65 ("tracing: Show last module text symbols in the stacktrace")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 103b193875b3978ea7d7e8335cd4fb3d36ed2c7d..de6d7f0e6206da04f79603cecfa1b212c9030c9c 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -9609,6 +9609,7 @@ static void free_trace_buffers(struct trace_array *tr)
                return;
 
        free_trace_buffer(&tr->array_buffer);
+       kfree(tr->module_delta);
 
 #ifdef CONFIG_TRACER_MAX_TRACE
        free_trace_buffer(&tr->max_buffer);