Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Gaurav Singh <gaurav1086@gmail.com>
To:     gaurav1086@gmail.com, Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@redhat.com>,
        Namhyung Kim <namhyung@kernel.org>,
        Tommi Rantala <tommi.t.rantala@nokia.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        linux-kernel@vger.kernel.org (open list:PERFORMANCE EVENTS SUBSYSTEM)
Subject: [PATCH] [perf] Fix null pointer deference in nest_epollfd
Date:   Wed, 17 Jun 2020 20:38:49 -0400
Message-Id: <20200618003916.26644-1-gaurav1086@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Add a NULL check for worker before dereferencing.

Signed-off-by: Gaurav Singh <gaurav1086@gmail.com>
---
 tools/perf/bench/epoll-wait.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/perf/bench/epoll-wait.c b/tools/perf/bench/epoll-wait.c
index 75dca9773186..42983eb7f82e 100644
--- a/tools/perf/bench/epoll-wait.c
+++ b/tools/perf/bench/epoll-wait.c
@@ -239,6 +239,9 @@ static void *workerfn(void *arg)
 
 static void nest_epollfd(struct worker *w)
 {
+	if (!w)
+		return;
+
 	unsigned int i;
 	struct epoll_event ev;
 	int efd = multiq ? w->epollfd : epollfd;
-- 
2.17.1