From patchwork Fri Aug 26 08:59:37 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [natty,natty/ti-omap4,CVE,1/1] perf: Fix software event overflow Date: Thu, 25 Aug 2011 22:59:37 -0000 From: Andy Whitcroft X-Patchwork-Id: 111727 Message-Id: <1314349177-31003-4-git-send-email-apw@canonical.com> To: kernel-team@lists.ubuntu.com Cc: Andy Whitcroft From: Peter Zijlstra The below patch is for -stable only, upstream has a much larger patch that contains the below hunk in commit a8b0ca17b80e92faab46ee7179ba9e99ccb61233 Vince found that under certain circumstances software event overflows go wrong and deadlock. Avoid trying to delete a timer from the timer callback. Reported-by: Vince Weaver Signed-off-by: Peter Zijlstra Signed-off-by: Greg Kroah-Hartman CVE-2011-2918 backported from commit 462fee3af72df0de7b60b96c525ffe8baf4db0f0 stable-3.0.y Signed-off-by: Andy Whitcroft --- kernel/perf_event.c | 7 ++----- 1 files changed, 2 insertions(+), 5 deletions(-) diff --git a/kernel/perf_event.c b/kernel/perf_event.c index b2536bd..478ec5d 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -4447,11 +4447,8 @@ static int __perf_event_overflow(struct perf_event *event, int nmi, if (events && atomic_dec_and_test(&event->event_limit)) { ret = 1; event->pending_kill = POLL_HUP; - if (nmi) { - event->pending_disable = 1; - irq_work_queue(&event->pending); - } else - perf_event_disable(event); + event->pending_disable = 1; + irq_work_queue(&event->pending); } if (event->overflow_handler)