2018-11-21 08:42:43

by Wen Yang

Subject: [PATCH 4/4] perf intel-pt/bts: fix potential NULL pointer dereference in intel_bts_process_auxtrace_info

This patch fixes a possible null pointer dereference in
intel_bts_process_auxtrace_info, detected by the semantic patch
deref_null.cocci, with the following warning:

./tools/perf/util/intel-bts.c:921:32-49: ERROR: session -> itrace_synth_opts is NULL but dereferenced.

Signed-off-by: Wen Yang <[email protected]>
Reviewed-by: Tan Hu <[email protected]>
CC: Julia Lawall <[email protected]>
---
tools/perf/util/intel-bts.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/intel-bts.c b/tools/perf/util/intel-bts.c
index 7b27d77..b0258f4 100644
--- a/tools/perf/util/intel-bts.c
+++ b/tools/perf/util/intel-bts.c
@@ -917,7 +917,8 @@ int intel_bts_process_auxtrace_info(union perf_event *event,
if (session->itrace_synth_opts && session->itrace_synth_opts->set) {
bts->synth_opts = *session->itrace_synth_opts;
} else {
- itrace_synth_opts__set_default(&bts->synth_opts,
+ if (session->itrace_synth_opts)
+ itrace_synth_opts__set_default(&bts->synth_opts,
session->itrace_synth_opts->default_no_sample);
if (session->itrace_synth_opts)
bts->synth_opts.thread_stack =
--
2.9.5

2018-11-21 09:16:08

by Adrian Hunter

Subject: Re: [PATCH 4/4] perf intel-pt/bts: fix potential NULL pointer dereference in intel_bts_process_auxtrace_info

On 21/11/18 9:43 AM, Wen Yang wrote:
> This patch fixes a possible null pointer dereference in
> intel_bts_process_auxtrace_info, detected by the semantic patch
> deref_null.cocci, with the following warning:
>
> ./tools/perf/util/intel-bts.c:921:32-49: ERROR: session -> itrace_synth_opts is NULL but dereferenced.
>
> Signed-off-by: Wen Yang <[email protected]>
> Reviewed-by: Tan Hu <[email protected]>
> CC: Julia Lawall <[email protected]>
> ---
> tools/perf/util/intel-bts.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/intel-bts.c b/tools/perf/util/intel-bts.c
> index 7b27d77..b0258f4 100644
> --- a/tools/perf/util/intel-bts.c
> +++ b/tools/perf/util/intel-bts.c
> @@ -917,7 +917,8 @@ int intel_bts_process_auxtrace_info(union perf_event *event,
> if (session->itrace_synth_opts && session->itrace_synth_opts->set) {
> bts->synth_opts = *session->itrace_synth_opts;
> } else {
> - itrace_synth_opts__set_default(&bts->synth_opts,
> + if (session->itrace_synth_opts)
> + itrace_synth_opts__set_default(&bts->synth_opts,
> session->itrace_synth_opts->default_no_sample);
> if (session->itrace_synth_opts)
> bts->synth_opts.thread_stack =
>

See response to patch 1.