Commit 80f0d631 authored by Zilin Guan's avatar Zilin Guan Committed by Steven Rostedt (Google)
Browse files

tracing: Fix memory leaks in create_field_var() 

The function create_field_var() allocates memory for 'val' through
create_hist_field() inside parse_atom(), and for 'var' through
create_var(), which in turn allocates var->type and var->var.name
internally. Simply calling kfree() to release these structures will
result in memory leaks.

Use destroy_hist_field() to properly free 'val', and explicitly release
the memory of var->type and var->var.name before freeing 'var' itself.

Link: https://patch.msgid.link/20251106120132.3639920-1-zilin@seu.edu.cn


Fixes: 02205a67 ("tracing: Add support for 'field variables'")
Signed-off-by: default avatarZilin Guan <zilin@seu.edu.cn>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent aa997d2d

kernel/trace/trace_events_hist.c

+4 −2
Original line number Diff line number Diff line
@@ -3272,14 +3272,16 @@ static struct field_var *create_field_var(struct hist_trigger_data *hist_data, 
	var = create_var(hist_data, file, field_name, val->size, val->type);

	if (IS_ERR(var)) {

		hist_err(tr, HIST_ERR_VAR_CREATE_FIND_FAIL, errpos(field_name));

		kfree(val);

		destroy_hist_field(val, 0);

		ret = PTR_ERR(var);

		goto err;

	}



	field_var = kzalloc(sizeof(struct field_var), GFP_KERNEL);

	if (!field_var) {

		kfree(val);

		destroy_hist_field(val, 0);

		kfree_const(var->type);

		kfree(var->var.name);

		kfree(var);

		ret =  -ENOMEM;

		goto err;