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: v5.15.138~73
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=21b07a2e6095ea57356527d20fe5bf2a5adbac3d;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 1732f6548bc6c..8e1290340aaf6 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -13277,7 +13277,8 @@ static int inherit_group(struct perf_event *parent_event,
 		    !perf_get_aux_event(child_ctr, leader))
 			return -EINVAL;
 	}
-	leader->group_generation = parent_event->group_generation;
+	if (leader)
+		leader->group_generation = parent_event->group_generation;
 	return 0;
 }