From patchwork Tue Mar 28 11:25:48 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tetsuo Handa X-Patchwork-Id: 13190932 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5187DC76195 for ; Tue, 28 Mar 2023 11:26:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230156AbjC1L0Q (ORCPT ); Tue, 28 Mar 2023 07:26:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41754 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232394AbjC1L0P (ORCPT ); Tue, 28 Mar 2023 07:26:15 -0400 Received: from www262.sakura.ne.jp (www262.sakura.ne.jp [202.181.97.72]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2BD0C3C22 for ; Tue, 28 Mar 2023 04:26:11 -0700 (PDT) Received: from fsav414.sakura.ne.jp (fsav414.sakura.ne.jp [133.242.250.113]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 32SBPlIK066834; Tue, 28 Mar 2023 20:25:47 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav414.sakura.ne.jp (F-Secure/fsigk_smtp/550/fsav414.sakura.ne.jp); Tue, 28 Mar 2023 20:25:47 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/fsav414.sakura.ne.jp) Received: from [192.168.1.6] (M106072142033.v4.enabler.ne.jp [106.72.142.33]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id 32SBPlZv066831 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NO); Tue, 28 Mar 2023 20:25:47 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Message-ID: Date: Tue, 28 Mar 2023 20:25:48 +0900 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.9.0 Content-Language: en-US To: Henrik Rydberg , Dmitry Torokhov Cc: "linux-input@vger.kernel.org" From: Tetsuo Handa Subject: [PATCH (repost)] Input: MT - use __GFP_NOWARN allocation at input_mt_init_slots() Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org syzbot is reporting too large allocation at input_mt_init_slots(), for num_slots is supplied from userspace using ioctl(UI_DEV_CREATE). Use __GFP_NOWARN. Also, replace n2 with array_size(), for 32bits variable n2 will overflow if num_slots >= 65536 and will cause out of bounds read/write at input_mt_set_matrix()/input_mt_set_slots() on architectures where PAGE_SIZE > 4096 is available (e.g. PPC64). Reported-by: syzbot Link: https://syzkaller.appspot.com/bug?extid=0122fa359a69694395d5 Signed-off-by: Tetsuo Handa --- Dmitry Torokhov proposed limiting max size to accept. But since it seems that nobody knows appropriate max size to accept, reposting as-is. https://lkml.kernel.org/r/03e8c3f0-bbbf-af37-6f52-67547cbd4cde@I-love.SAKURA.ne.jp drivers/input/input-mt.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c index 14b53dac1253..cf74579462ba 100644 --- a/drivers/input/input-mt.c +++ b/drivers/input/input-mt.c @@ -47,7 +47,7 @@ int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots, if (mt) return mt->num_slots != num_slots ? -EINVAL : 0; - mt = kzalloc(struct_size(mt, slots, num_slots), GFP_KERNEL); + mt = kzalloc(struct_size(mt, slots, num_slots), GFP_KERNEL | __GFP_NOWARN); if (!mt) goto err_mem; @@ -80,8 +80,8 @@ int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots, if (flags & INPUT_MT_SEMI_MT) __set_bit(INPUT_PROP_SEMI_MT, dev->propbit); if (flags & INPUT_MT_TRACK) { - unsigned int n2 = num_slots * num_slots; - mt->red = kcalloc(n2, sizeof(*mt->red), GFP_KERNEL); + mt->red = kcalloc(array_size(num_slots, num_slots), + sizeof(*mt->red), GFP_KERNEL | __GFP_NOWARN); if (!mt->red) goto err_mem; }