From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752232Ab0IMOih (ORCPT ); Mon, 13 Sep 2010 10:38:37 -0400 Received: from smtp-out.google.com ([74.125.121.35]:36502 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751728Ab0IMOif (ORCPT ); Mon, 13 Sep 2010 10:38:35 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=message-id:from:date:to:reply-to:cc:subject:x-system-of-record; b=lch5ZWwBAoH2T4bqCYtznwbjQ9uzgdDqnelVFfcQWCJxD9bn9ROzVh+oy9fdoVBbr Y0g4VutpQad6g1RDpv0zA== Message-ID: <4c8e3766.991ce30a.32cd.fffff5f0@mx.google.com> From: Stephane Eranian Date: Mon, 13 Sep 2010 16:36:01 +0200 To: linux-kernel@vger.kernel.org Reply-to: eranian@google.com Cc: peterz@infradead.org, mingo@elte.hu, paulus@samba.org, davem@davemloft.net, fweisbec@gmail.com, perfmon2-devel@lists.sf.net, eranian@gmail.com, eranian@google.com, robert.richter@amd.com Subject: [PATCH] perf_events: fix NULL point in free_event() X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Without the following patch, perf top as non-root and paranoid cpu set causes a NULL pointer dereference in free_event() because event->ctx is NULL. free_event() may be called, on the error path, before event->ctx is set. Signed-off-by: Stephane Eranian diff --git a/kernel/perf_event.c b/kernel/perf_event.c index f29b525..a7d5e7a 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -2150,7 +2150,8 @@ static void free_event(struct perf_event *event) if (event->destroy) event->destroy(event); - put_ctx(event->ctx); + if (event->ctx) + put_ctx(event->ctx); call_rcu(&event->rcu_head, free_event_rcu); }