From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mikhail Kulemin , Hemant Kumar Shaw , Oleg Nesterov , Anton Arapov , Ingo Molnar , masami.hiramatsu.pt@hitachi.com, srikar@linux.vnet.ibm.com, systemtap@sourceware.org Subject: [ 091/117] uprobes: Fix utask->depth accounting in handle_trampoline() Date: Tue, 24 Sep 2013 17:19:17 -0700 Message-Id: <20130925001750.865517088@linuxfoundation.org> In-Reply-To: <20130925001740.833541979@linuxfoundation.org> References: <20130925001740.833541979@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Oleg Nesterov commit 878b5a6efd38030c7a90895dc8346e8fb1e09b4c upstream. 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. Reported-by: Mikhail Kulemin Reported-by: Hemant Kumar Shaw Signed-off-by: Oleg Nesterov Acked-by: Anton Arapov Cc: masami.hiramatsu.pt@hitachi.com Cc: srikar@linux.vnet.ibm.com Cc: systemtap@sourceware.org Link: http://lkml.kernel.org/r/20130911154726.GA8093@redhat.com Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- kernel/events/uprobes.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1682,12 +1682,10 @@ static bool handle_trampoline(struct pt_ tmp = ri; ri = ri->next; kfree(tmp); + utask->depth--; if (!chained) break; - - utask->depth--; - BUG_ON(!ri); }