From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755467Ab3IKPyT (ORCPT ); Wed, 11 Sep 2013 11:54:19 -0400 Received: from mx1.redhat.com ([209.132.183.28]:15761 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754376Ab3IKPyS (ORCPT ); Wed, 11 Sep 2013 11:54:18 -0400 Date: Wed, 11 Sep 2013 17:47:26 +0200 From: Oleg Nesterov To: Ingo Molnar Cc: anton@redhat.com, Hemant Kumar Shaw , masami.hiramatsu.pt@hitachi.com, Mikhail Kulemin , srikar@linux.vnet.ibm.com, systemtap@sourceware.org, linux-kernel@vger.kernel.org Subject: [PATCH] uprobes: Fix utask->depth accounting in handle_trampoline() Message-ID: <20130911154726.GA8093@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently utask->depth is simply the number of allocated/pending return_instance's in uprobe_task->return_instances list. handle_trampoline() should decrement this counter every time we handle/free an instance, but due to typo it does this only if ->chained == T. This means that in the likely case this counter is never decremented and the probed task can't report more than MAX_URETPROBE_DEPTH events. Cc: stable@vger.kernel.org Signed-off-by: Oleg Nesterov Reported-by: Mikhail Kulemin Reported-by: Hemant Kumar Shaw --- kernel/events/uprobes.c | 4 +--- 1 files changed, 1 insertions(+), 3 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index f356974..ad8e1bd 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1682,12 +1682,10 @@ static bool handle_trampoline(struct pt_regs *regs) tmp = ri; ri = ri->next; kfree(tmp); + utask->depth--; if (!chained) break; - - utask->depth--; - BUG_ON(!ri); } -- 1.5.5.1