Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754179AbcKULs6 (ORCPT ); Mon, 21 Nov 2016 06:48:58 -0500 Received: from mail-wm0-f51.google.com ([74.125.82.51]:37826 "EHLO mail-wm0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753632AbcKULs5 (ORCPT ); Mon, 21 Nov 2016 06:48:57 -0500 MIME-Version: 1.0 In-Reply-To: <20161121114417.GA4158@leon.nu> References: <1479723531-17940-1-git-send-email-dvyukov@google.com> <20161121114417.GA4158@leon.nu> From: Dmitry Vyukov Date: Mon, 21 Nov 2016 12:48:35 +0100 Message-ID: Subject: Re: [PATCH v2] infiniband: remove WARN that is not kernel bug To: Leon Romanovsky Cc: syzkaller , Jason Gunthorpe , Valdis.Kletnieks@vt.edu, dledford@redhat.com, sean.hefty@intel.com, Hal Rosenstock , linux-rdma@vger.kernel.org, LKML Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2291 Lines: 61 On Mon, Nov 21, 2016 at 12:44 PM, Leon Romanovsky wrote: > On Mon, Nov 21, 2016 at 11:30:21AM +0100, Dmitry Vyukov wrote: >> On Mon, Nov 21, 2016 at 11:25 AM, Miroslav Benes wrote: >> > On Mon, 21 Nov 2016, Dmitry Vyukov wrote: >> > >> >> WARNINGs mean kernel bugs. >> >> The one in ucma_write() points to user programming error >> >> or a malicious attempt. This is not a kernel bug, remove it. >> >> >> >> BUG/WARNs that are not kernel bugs hinder automated testing effots. >> >> >> >> Signed-off-by: Dmitry Vyukov >> >> Cc: Doug Ledford >> >> Cc: Sean Hefty >> >> Cc: Hal Rosenstock >> >> Cc: Leon Romanovsky >> >> Cc: linux-rdma@vger.kernel.org >> >> Cc: linux-kernel@vger.kernel.org >> >> Cc: syzkaller@googlegroups.com >> >> >> >> --- >> >> Changes since v1: >> >> - added printk_once >> >> --- >> >> drivers/infiniband/core/ucma.c | 5 ++++- >> >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> >> >> diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c >> >> index 9520154..405d0ce 100644 >> >> --- a/drivers/infiniband/core/ucma.c >> >> +++ b/drivers/infiniband/core/ucma.c >> >> @@ -1584,8 +1584,11 @@ static ssize_t ucma_write(struct file *filp, const char __user *buf, >> >> struct rdma_ucm_cmd_hdr hdr; >> >> ssize_t ret; >> >> >> >> - if (WARN_ON_ONCE(!ib_safe_file_access(filp))) >> >> + if (!ib_safe_file_access(filp)) { >> >> + printk_once("ucma_write: process %d (%s) tried to do something hinky\n", >> >> + task_tgid_vnr(current), current->comm); >> >> return -EACCES; >> >> + } >> >> >> >> if (len < sizeof(hdr)) >> >> return -EINVAL; >> > >> > FWIW, WARN_ON_ONCE came with commit e6bd18f57aad ("IB/security: Restrict >> > use of the write() interface"). Would it make sense to change the other >> > places as well? >> >> >> I guess so. >> Can I ask somebody of infiniband maintainers to take care of this? > > Please see below, > Hope it helps. In ib_ucm_write function there is a wrong prefix: + pr_err_once("ucm_write: process %d (%s) tried to do something hinky\n", Otherwise looks good. Thanks.