[PATCH v1 06/11] perf hists: Smatch: Fix potential NULL pointer dereference

Leo Yan
2019-07-02T10:35:38Z

Based on the following report from Smatch, fix the potential
NULL pointer dereference check.

tools/perf/ui/browsers/hists.c:641
hist_browser__run() error: we previously assumed 'hbt' could be
null (see line 625)

tools/perf/ui/browsers/hists.c:3088
perf_evsel__hists_browse() error: we previously assumed
'browser->he_selection' could be null (see line 2902)

tools/perf/ui/browsers/hists.c:3272
perf_evsel_menu__run() error: we previously assumed 'hbt' could be
null (see line 3260)

This patch firstly validating the pointers before access them, so can
fix potential NULL pointer dereference.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
tools/perf/ui/browsers/hists.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index 3421ecbdd3f0..2ba33040ddd8 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -638,7 +638,9 @@ int hist_browser__run(struct hist_browser *browser, const char *help,
switch (key) {
case K_TIMER: {
u64 nr_entries;
- hbt->timer(hbt->arg);
+
+ if (hbt)
+ hbt->timer(hbt->arg);

if (hist_browser__has_filter(browser) ||
symbol_conf.report_hierarchy)
@@ -2819,7 +2821,7 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
{
struct hists *hists = evsel__hists(evsel);
struct hist_browser *browser = perf_evsel_browser__new(evsel, hbt, env, annotation_opts);
- struct branch_info *bi;
+ struct branch_info *bi = NULL;
#define MAX_OPTIONS 16
char *options[MAX_OPTIONS];
struct popup_action actions[MAX_OPTIONS];
@@ -3085,7 +3087,9 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
goto skip_annotation;

if (sort__mode == SORT_MODE__BRANCH) {
- bi = browser->he_selection->branch_info;
+
+ if (browser->he_selection)
+ bi = browser->he_selection->branch_info;

if (bi == NULL)
goto skip_annotation;
@@ -3269,7 +3273,8 @@ static int perf_evsel_menu__run(struct perf_evsel_menu *menu,

switch (key) {
case K_TIMER:
- hbt->timer(hbt->arg);
+ if (hbt)
+ hbt->timer(hbt->arg);

if (!menu->lost_events_warned &&
menu->lost_events &&
--
2.17.1