From mboxrd@z Thu Jan 1 00:00:00 1970 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, USER_AGENT_GIT autolearn=unavailable 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 589B0C43603 for ; Wed, 12 May 2021 16:18:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2888B61D74 for ; Wed, 12 May 2021 16:18:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239736AbhELQPp (ORCPT ); Wed, 12 May 2021 12:15:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:50218 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234022AbhELPcB (ORCPT ); Wed, 12 May 2021 11:32:01 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 31E3461106; Wed, 12 May 2021 15:16:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620832593; bh=om4ymYeSu37bHGDCB/1xijYMwPt9F0hOXoCQtMmZfng=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=U06enR/+jAVdM2f3f7TnLF9gqTzeZUDIHMbJYkBF32Bo7HLZXbqAZGMy7/rya8wyp 6cFJ52DYB6RT0AJo9PWnySvooSTC3jLgj0WZHvW3E176h9+G4/xUT8HdQDu/rjLdks ePhwd+EMTt2QoU+1JjWiuxbrrIGPGx/Pg1OwqsBU= 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 5.10 344/530] io_uring: fix overflows checks in provide buffers Date: Wed, 12 May 2021 16:47:34 +0200 Message-Id: <20210512144831.099914180@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210512144819.664462530@linuxfoundation.org> References: <20210512144819.664462530@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 55e214defb42..369ec81033d6 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -527,7 +527,7 @@ struct io_splice { struct io_provide_buf { struct file *file; __u64 addr; - __s32 len; + __u32 len; __u32 bgid; __u16 nbufs; __u16 bid; @@ -3996,7 +3996,7 @@ static int io_remove_buffers(struct io_kiocb *req, bool force_nonblock, 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; @@ -4010,6 +4010,12 @@ 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; -- 2.30.2