From patchwork Sat Apr 27 11:15:12 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tetsuo Handa X-Patchwork-Id: 792774 Received: from www262.sakura.ne.jp (www262.sakura.ne.jp [202.181.97.72]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F1B164A990 for ; Sat, 27 Apr 2024 11:15:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=202.181.97.72 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714216534; cv=none; b=rnxNkT0TazmX4oiKFv/SmwkjCLwUXC7a6kP14VWkO/wCDbBLGEu8vY4Ve57lSa2LjxgYQ643zVz88miPIWIViwAUSbxiqLQQUH3tfIThrXZsLP4XGZY8o3jwMDVLmDCg9CEVPalfhLk3Y5Vsob6gpwkQWfNNeEY9PrpChazLb8c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714216534; c=relaxed/simple; bh=GB8u12djRIME1B6PDT7eW1YyY3V8yemgIyYdDJiwli4=; h=Message-ID:Date:MIME-Version:Subject:From:To:Cc:References: In-Reply-To:Content-Type; b=OscMSqlfPt3kcMUJOHY2Ynkwltg+k8vtiSV0BzJfhOeoVCLzWovCG6DQVSUefWdp55D9lwcfr7zjTDIx1Fa2VvC3CPsu2OZJfJEBCKwetuUePC9mr2DO0y5Sd5CLCZtoTFJddZ2Ckbwo64/pk2mtoz0/t2MD/VOPpRyiPVHmRHM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=I-love.SAKURA.ne.jp; spf=pass smtp.mailfrom=I-love.SAKURA.ne.jp; arc=none smtp.client-ip=202.181.97.72 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=I-love.SAKURA.ne.jp Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=I-love.SAKURA.ne.jp Received: from fsav415.sakura.ne.jp (fsav415.sakura.ne.jp [133.242.250.114]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 43RBFCWg051833; Sat, 27 Apr 2024 20:15:12 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav415.sakura.ne.jp (F-Secure/fsigk_smtp/550/fsav415.sakura.ne.jp); Sat, 27 Apr 2024 20:15:12 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/fsav415.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 43RBFCDI051830 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NO); Sat, 27 Apr 2024 20:15:12 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Message-ID: Date: Sat, 27 Apr 2024 20:15:12 +0900 Precedence: bulk X-Mailing-List: linux-input@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: [PATCH v2] Input: MT - limit max slots From: Tetsuo Handa To: Dmitry Torokhov , Henrik Rydberg Cc: syzkaller-bugs@googlegroups.com, syzbot , akpm@linux-foundation.org, "linux-input@vger.kernel.org" References: <000000000000de2f4f05b8942be9@google.com> <6d878e01-6c2f-8766-2578-c95030442369@I-love.SAKURA.ne.jp> <03e8c3f0-bbbf-af37-6f52-67547cbd4cde@I-love.SAKURA.ne.jp> Content-Language: en-US In-Reply-To: <03e8c3f0-bbbf-af37-6f52-67547cbd4cde@I-love.SAKURA.ne.jp> syzbot is reporting too large allocation at input_mt_init_slots(), for num_slots is supplied from userspace using ioctl(UI_DEV_CREATE). Since nobody knows possible max slots, this patch chose 1024. Reported-by: syzbot Closes: https://syzkaller.appspot.com/bug?extid=0122fa359a69694395d5 Suggested-by: Dmitry Torokhov Signed-off-by: Tetsuo Handa --- Changes in v2: Limit max slots instead of using __GFP_NOWARN. drivers/input/input-mt.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c index 14b53dac1253..6b04a674f832 100644 --- a/drivers/input/input-mt.c +++ b/drivers/input/input-mt.c @@ -46,6 +46,9 @@ int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots, return 0; if (mt) return mt->num_slots != num_slots ? -EINVAL : 0; + /* Arbitrary limit for avoiding too large memory allocation. */ + if (num_slots > 1024) + return -EINVAL; mt = kzalloc(struct_size(mt, slots, num_slots), GFP_KERNEL); if (!mt)