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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 9259CC433ED for ; Thu, 29 Apr 2021 10:36:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 473A861412 for ; Thu, 29 Apr 2021 10:36:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232629AbhD2Khl (ORCPT ); Thu, 29 Apr 2021 06:37:41 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:40896 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232245AbhD2Khk (ORCPT ); Thu, 29 Apr 2021 06:37:40 -0400 Received: from 1.general.cking.uk.vpn ([10.172.193.212]) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1lc42O-0007Og-Id; Thu, 29 Apr 2021 10:36:52 +0000 Subject: Re: [PATCH][next] io_uring: Fix memory leak on error return path. To: Pavel Begunkov , Jens Axboe , io-uring@vger.kernel.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org References: <20210429102654.58943-1-colin.king@canonical.com> <6929b598-ac2f-521a-8e96-dbbf295d137a@gmail.com> From: Colin Ian King Message-ID: <0aa1bcfe-9e45-ac54-1292-43caad8b9b06@canonical.com> Date: Thu, 29 Apr 2021 11:36:51 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <6929b598-ac2f-521a-8e96-dbbf295d137a@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 29/04/2021 11:32, Pavel Begunkov wrote: > On 4/29/21 11:26 AM, Colin King wrote: >> From: Colin Ian King >> >> Currently the -EINVAL error return path is leaking memory allocated >> to data. Fix this by kfree'ing data before the return. >> >> Addresses-Coverity: ("Resource leak") >> Fixes: c3a40789f6ba ("io_uring: allow empty slots for reg buffers") >> Signed-off-by: Colin Ian King >> --- >> fs/io_uring.c | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/fs/io_uring.c b/fs/io_uring.c >> index 47c2f126f885..beeb477e4f6a 100644 >> --- a/fs/io_uring.c >> +++ b/fs/io_uring.c >> @@ -8417,8 +8417,10 @@ static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, >> ret = io_buffer_validate(&iov); >> if (ret) >> break; >> - if (!iov.iov_base && tag) >> + if (!iov.iov_base && tag) {> + kfree(data); >> return -EINVAL; >> + } > > Buggy indeed, should have been: > > ret = -EINVAL; > break; Ah, thanks. > > Colin, can you resend with the change? Will do in a moment or so. > >> >> ret = io_sqe_buffer_register(ctx, &iov, &ctx->user_bufs[i], >> &last_hpage); >> >