[PATCH] perf annotate-data: Fix a buffer overflow in TUI browser

[PATCH] perf annotate-data: Fix a buffer overflow in TUI browser

[Namhyung Kim]

In get_member_overhead(), k is updated when it has a entry in the
histogram.  But the entry->hists array is allocated with the number of
evsel in the group.  So the k should be reset when it iterates the event
using for_each_group_evsel(), otherwise it'd crash due to a buffer
overflow.

Fixes: cb1898f58e0f ("perf annotate-data: Support --skip-empty option")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/ui/browsers/annotate-data.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/ui/browsers/annotate-data.c b/tools/perf/ui/browsers/annotate-data.c
index c3db80a7589a..a937b55da736 100644
--- a/tools/perf/ui/browsers/annotate-data.c
+++ b/tools/perf/ui/browsers/annotate-data.c
@@ -46,11 +46,12 @@ static int get_member_overhead(struct annotated_data_type *adt,
 	struct annotated_member *member = entry->data;
 	int i, k;
 
-	for (i = 0, k = 0; i < member->size; i++) {
+	for (i = 0; i < member->size; i++) {
 		struct type_hist *h;
 		struct evsel *evsel;
 		int offset = member->offset + i;
 
+		k = 0;
 		for_each_group_evsel(evsel, leader) {
 			if (symbol_conf.skip_empty &&
 			    evsel__hists(evsel)->stats.nr_samples == 0)
-- 
2.46.0.76.ge559c4bf1a-goog

Re: [PATCH] perf annotate-data: Fix a buffer overflow in TUI browser

[Arnaldo Carvalho de Melo]

On Sat, Aug 10, 2024 at 12:15:02PM -0700, Namhyung Kim wrote:
> In get_member_overhead(), k is updated when it has a entry in the
> histogram.  But the entry->hists array is allocated with the number of
> evsel in the group.  So the k should be reset when it iterates the event
> using for_each_group_evsel(), otherwise it'd crash due to a buffer
> overflow.
> 
> Fixes: cb1898f58e0f ("perf annotate-data: Support --skip-empty option")

Thanks, applied to perf-tools-next,

- Arnaldo

> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
>  tools/perf/ui/browsers/annotate-data.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/ui/browsers/annotate-data.c b/tools/perf/ui/browsers/annotate-data.c
> index c3db80a7589a..a937b55da736 100644
> --- a/tools/perf/ui/browsers/annotate-data.c
> +++ b/tools/perf/ui/browsers/annotate-data.c
> @@ -46,11 +46,12 @@ static int get_member_overhead(struct annotated_data_type *adt,
>  	struct annotated_member *member = entry->data;
>  	int i, k;
>  
> -	for (i = 0, k = 0; i < member->size; i++) {
> +	for (i = 0; i < member->size; i++) {
>  		struct type_hist *h;
>  		struct evsel *evsel;
>  		int offset = member->offset + i;
>  
> +		k = 0;
>  		for_each_group_evsel(evsel, leader) {
>  			if (symbol_conf.skip_empty &&
>  			    evsel__hists(evsel)->stats.nr_samples == 0)
> -- 
> 2.46.0.76.ge559c4bf1a-goog