Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934377AbeAKOkf (ORCPT + 1 other); Thu, 11 Jan 2018 09:40:35 -0500 Received: from mail-vk0-f68.google.com ([209.85.213.68]:33906 "EHLO mail-vk0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932986AbeAKOkd (ORCPT ); Thu, 11 Jan 2018 09:40:33 -0500 X-Google-Smtp-Source: ACJfBotnSl5L0kVptxWYu3sY2zcuKw9WW8yNQdVnC8gzhZp2gOffYGbJdTsHHUBFC0fmc4QQj1YmNfhUpTgaiD5CGbw= MIME-Version: 1.0 In-Reply-To: <20180110231509.GA14154@embeddedor.com> References: <20180110231509.GA14154@embeddedor.com> From: Oded Gabbay Date: Thu, 11 Jan 2018 16:40:02 +0200 Message-ID: Subject: Re: [PATCH v2] drm/amdkfd: Fix potential NULL pointer dereferences To: "Gustavo A. R. Silva" Cc: Felix Kuehling , Alex Deucher , =?UTF-8?Q?Christian_K=C3=B6nig?= , David Airlie , Maling list - DRI developers , amd-gfx list , "Linux-Kernel@Vger. Kernel. Org" Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On Thu, Jan 11, 2018 at 1:15 AM, Gustavo A. R. Silva wrote: > In case kfd_get_process_device_data returns null, there are some > null pointer dereferences in functions kfd_bind_processes_to_device > and kfd_unbind_processes_from_device. > > Fix this by printing a WARN_ON for PDDs that aren't found and skip > them with continue statements. > > Addresses-Coverity-ID: 1463794 ("Dereference null return value") > Addresses-Coverity-ID: 1463772 ("Dereference null return value") > Suggested-by: Felix Kuehling > Signed-off-by: Gustavo A. R. Silva > --- > Changes in v2: > Print a WARN_ON and skip PDDs that aren't found instead of returning > an error. > > drivers/gpu/drm/amd/amdkfd/kfd_process.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c > index a22fb071..4ff5f0f 100644 > --- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c > @@ -461,7 +461,8 @@ int kfd_bind_processes_to_device(struct kfd_dev *dev) > hash_for_each_rcu(kfd_processes_table, temp, p, kfd_processes) { > mutex_lock(&p->mutex); > pdd = kfd_get_process_device_data(dev, p); > - if (pdd->bound != PDD_BOUND_SUSPENDED) { > + > + if (WARN_ON(!pdd) || pdd->bound != PDD_BOUND_SUSPENDED) { > mutex_unlock(&p->mutex); > continue; > } > @@ -501,6 +502,11 @@ void kfd_unbind_processes_from_device(struct kfd_dev *dev) > mutex_lock(&p->mutex); > pdd = kfd_get_process_device_data(dev, p); > > + if (WARN_ON(!pdd)) { > + mutex_unlock(&p->mutex); > + continue; > + } > + > if (pdd->bound == PDD_BOUND) > pdd->bound = PDD_BOUND_SUSPENDED; > mutex_unlock(&p->mutex); > -- > 2.7.4 > This patch is: Reviewed-by: Oded Gabbay