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

Message ID 20190702103420.27540-7-leo.yan@linaro.org
State Superseded
Headers show
Series
  • perf: Fix errors detected by Smatch
Related show

Commit Message

Leo Yan July 2, 2019, 10:34 a.m.
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(-)

-- 
2.17.1

Comments

Jiri Olsa July 2, 2019, 11:07 a.m. | #1
On Tue, Jul 02, 2019 at 06:34:15PM +0800, Leo Yan wrote:
> 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: {


not sure this can really happen, perhaps WARN_ON_ONCE(!hbt) would be
good in here

jirka

>  			u64 nr_entries;

> -			hbt->timer(hbt->arg);

> +

> +			if (hbt)

> +				hbt->timer(hbt->arg);

>  

>  			if (hist_browser__has_filter(browser) ||

>  			    symbol_conf.report_hierarchy)


SNIP

Patch

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 &&