Commit 240dd511 authored Sep 07, 2020 by Tom Rix Committed by Greg Kroah-Hartman Oct 01, 2020

tracing: fix double free

commit 46bbe5c671e06f070428b9be142cc4ee5cedebac upstream.

clang static analyzer reports this problem

trace_events_hist.c:3824:3: warning: Attempt to free
  released memory
    kfree(hist_data->attrs->var_defs.name[i]);

In parse_var_defs() if there is a problem allocating
var_defs.expr, the earlier var_defs.name is freed.
This free is duplicated by free_var_defs() which frees
the rest of the list.

Because free_var_defs() has to run anyway, remove the
second free fom parse_var_defs().

Link: https://lkml.kernel.org/r/20200907135845.15804-1-trix@redhat.com



Cc: stable@vger.kernel.org
Fixes: 30350d65 ("tracing: Add variable support to hist triggers")
Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent e794df7b

kernel/trace/trace_events_hist.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -4225,7 +4225,6 @@ static int parse_var_defs(struct hist_trigger_data *hist_data)

		s = kstrdup(field_str, GFP_KERNEL);
		if (!s) {
		kfree(hist_data->attrs->var_defs.name[n_vars]);
		ret = -ENOMEM;
		goto free;
		}