Commit 17fda38f authored Jun 17, 2015 by Linus Torvalds

Merge tag 'trace-fix-filter-4.1-rc8' of...

Merge tag 'trace-fix-filter-4.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing filter fix from Steven Rostedt:
 "Vince Weaver reported a warning when he added perf event filters into
  his fuzzer tests.  There's a missing check of balanced operations when
  parenthesis are used, and this triggers a WARN_ON() and when reading
  the failure, the filter reports no failure occurred.

  The operands were not being checked if they match, this adds that"

* tag 'trace-fix-filter-4.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Have filter check for balanced ops

parents 32e0e382 2cf30dc1

kernel/trace/trace_events_filter.c

+9 −2

Original line number	Diff line number	Diff line
		@@ -1369,19 +1369,26 @@ static int check_preds(struct filter_parse_state *ps)
		{
		int n_normal_preds = 0, n_logical_preds = 0;
		struct postfix_elt *elt;
		int cnt = 0;

		list_for_each_entry(elt, &ps->postfix, list) {
		if (elt->op == OP_NONE)
		if (elt->op == OP_NONE) {
		cnt++;
		continue;
		}

		if (elt->op == OP_AND \|\| elt->op == OP_OR) {
		n_logical_preds++;
		cnt--;
		continue;
		}
		if (elt->op != OP_NOT)
		cnt--;
		n_normal_preds++;
		WARN_ON_ONCE(cnt < 0);
		}

		if (!n_normal_preds \|\| n_logical_preds >= n_normal_preds) {
		if (cnt != 1 \|\| !n_normal_preds \|\| n_logical_preds >= n_normal_preds) {
		parse_error(ps, FILT_ERR_INVALID_FILTER, 0);
		return -EINVAL;
		}