From: Peter Zijlstra <peterz@infradead.org>
Date: Tue, 24 Oct 2023 09:42:21 +0000 (+0200)
Subject: perf/core: Fix potential NULL deref
X-Git-Tag: v4.14.329~36
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ce7c6ad176a3c101826735365a04f961921fe7dd;p=thirdparty%2Fkernel%2Fstable.git

perf/core: Fix potential NULL deref

commit a71ef31485bb51b846e8db8b3a35e432cc15afb5 upstream.

Smatch is awesome.

Fixes: 32671e3799ca ("perf: Disallow mis-matched inherited group reads")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 7ece49c14b744..262079890b134 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -11059,7 +11059,8 @@ static int inherit_group(struct perf_event *parent_event,
 		if (IS_ERR(child_ctr))
 			return PTR_ERR(child_ctr);
 	}
-	leader->group_generation = parent_event->group_generation;
+	if (leader)
+		leader->group_generation = parent_event->group_generation;
 	return 0;
 }