From patchwork Wed May 12 14:47:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "gregkh@linuxfoundation.org" X-Patchwork-Id: 436301 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4863FC2B9F7 for ; Wed, 12 May 2021 17:02:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2754C61221 for ; Wed, 12 May 2021 17:02:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343744AbhELQ7T (ORCPT ); Wed, 12 May 2021 12:59:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:35814 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243838AbhELQmJ (ORCPT ); Wed, 12 May 2021 12:42:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id BE00E61C3A; Wed, 12 May 2021 16:07:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620835652; bh=vac/PmXNIgxrJ7QjcWo+e62LDA7/kj5GZFUMfEqwEK0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OhxMSIkXaE2o/yJX66sirayXOzTmFt7kl/6H4fdYrWTMGPFmNgVk9DQzHe/0SbdvV KSWBCz8CT3lzWzFdmMzq6m6oKd/ry+/fpJpzfsbW6BjmDdRdQ733JF+85O+ZbIjAn7 ECkJB07CniN4rVsxZTEwKV8axNGr5N678lJMp32A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Colin Ian King , Pavel Begunkov , Jens Axboe , Sasha Levin Subject: [PATCH 5.12 430/677] io_uring: fix overflows checks in provide buffers Date: Wed, 12 May 2021 16:47:56 +0200 Message-Id: <20210512144851.626748341@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210512144837.204217980@linuxfoundation.org> References: <20210512144837.204217980@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Pavel Begunkov [ Upstream commit 38134ada0ceea3e848fe993263c0ff6207fd46e7 ] Colin reported before possible overflow and sign extension problems in io_provide_buffers_prep(). As Linus pointed out previous attempt did nothing useful, see d81269fecb8ce ("io_uring: fix provide_buffers sign extension"). Do that with help of check__overflow helpers. And fix struct io_provide_buf::len type, as it doesn't make much sense to keep it signed. Reported-by: Colin Ian King Fixes: efe68c1ca8f49 ("io_uring: validate the full range of provided buffers for access") Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/46538827e70fce5f6cdb50897cff4cacc490f380.1618488258.git.asml.silence@gmail.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- fs/io_uring.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 2bdd7eab6c66..144056b0cac9 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -614,7 +614,7 @@ struct io_splice { struct io_provide_buf { struct file *file; __u64 addr; - __s32 len; + __u32 len; __u32 bgid; __u16 nbufs; __u16 bid; @@ -3979,7 +3979,7 @@ static int io_remove_buffers(struct io_kiocb *req, unsigned int issue_flags) static int io_provide_buffers_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { - unsigned long size; + unsigned long size, tmp_check; struct io_provide_buf *p = &req->pbuf; u64 tmp; @@ -3993,6 +3993,12 @@ static int io_provide_buffers_prep(struct io_kiocb *req, p->addr = READ_ONCE(sqe->addr); p->len = READ_ONCE(sqe->len); + if (check_mul_overflow((unsigned long)p->len, (unsigned long)p->nbufs, + &size)) + return -EOVERFLOW; + if (check_add_overflow((unsigned long)p->addr, size, &tmp_check)) + return -EOVERFLOW; + size = (unsigned long)p->len * p->nbufs; if (!access_ok(u64_to_user_ptr(p->addr), size)) return -EFAULT;