From patchwork Mon Nov 15 03:57:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Leizhen (ThunderTown)" X-Patchwork-Id: 12618667 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 402D6C433F5 for ; Mon, 15 Nov 2021 03:58:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1381361C57 for ; Mon, 15 Nov 2021 03:58:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237245AbhKOEBj (ORCPT ); Sun, 14 Nov 2021 23:01:39 -0500 Received: from szxga03-in.huawei.com ([45.249.212.189]:27204 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237234AbhKOEB1 (ORCPT ); Sun, 14 Nov 2021 23:01:27 -0500 Received: from dggemv703-chm.china.huawei.com (unknown [172.30.72.54]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4HswNr0g0zz8vNd; Mon, 15 Nov 2021 11:56:44 +0800 (CST) Received: from dggpemm500006.china.huawei.com (7.185.36.236) by dggemv703-chm.china.huawei.com (10.3.19.46) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Mon, 15 Nov 2021 11:58:25 +0800 Received: from thunder-town.china.huawei.com (10.174.178.55) by dggpemm500006.china.huawei.com (7.185.36.236) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Mon, 15 Nov 2021 11:58:25 +0800 From: Zhen Lei To: Alexander Viro , David Howells , , CC: Zhen Lei Subject: [PATCH 1/2] pipe: fix potential use-after-free in pipe_read() Date: Mon, 15 Nov 2021 11:57:20 +0800 Message-ID: <20211115035721.1909-2-thunder.leizhen@huawei.com> X-Mailer: git-send-email 2.26.0.windows.1 In-Reply-To: <20211115035721.1909-1-thunder.leizhen@huawei.com> References: <20211115035721.1909-1-thunder.leizhen@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.178.55] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpemm500006.china.huawei.com (7.185.36.236) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Accessing buf->flags after pipe_buf_release(pipe, buf) is unsafe, because the 'buf' memory maybe freed. Fixes: e7d553d69cf6 ("pipe: Add notification lossage handling") Signed-off-by: Zhen Lei --- fs/pipe.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/pipe.c b/fs/pipe.c index 6d4342bad9f15b2..302f1e50ce3be1d 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -319,10 +319,12 @@ pipe_read(struct kiocb *iocb, struct iov_iter *to) } if (!buf->len) { + unsigned int __maybe_unused flags = buf->flags; + pipe_buf_release(pipe, buf); spin_lock_irq(&pipe->rd_wait.lock); #ifdef CONFIG_WATCH_QUEUE - if (buf->flags & PIPE_BUF_FLAG_LOSS) + if (flags & PIPE_BUF_FLAG_LOSS) pipe->note_loss = true; #endif tail++; From patchwork Mon Nov 15 03:57:21 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Leizhen (ThunderTown)" X-Patchwork-Id: 12618669 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CCB6FC433F5 for ; Mon, 15 Nov 2021 03:58:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AEE1061C4F for ; Mon, 15 Nov 2021 03:58:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237254AbhKOEBm (ORCPT ); Sun, 14 Nov 2021 23:01:42 -0500 Received: from szxga02-in.huawei.com ([45.249.212.188]:15823 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237235AbhKOEB1 (ORCPT ); Sun, 14 Nov 2021 23:01:27 -0500 Received: from dggemv711-chm.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4HswQQ6GVHz5pVP; Mon, 15 Nov 2021 11:58:06 +0800 (CST) Received: from dggpemm500006.china.huawei.com (7.185.36.236) by dggemv711-chm.china.huawei.com (10.1.198.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Mon, 15 Nov 2021 11:58:25 +0800 Received: from thunder-town.china.huawei.com (10.174.178.55) by dggpemm500006.china.huawei.com (7.185.36.236) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Mon, 15 Nov 2021 11:58:25 +0800 From: Zhen Lei To: Alexander Viro , David Howells , , CC: Zhen Lei Subject: [PATCH 2/2] pipe: delete a duplicate line of code in pipe_write() Date: Mon, 15 Nov 2021 11:57:21 +0800 Message-ID: <20211115035721.1909-3-thunder.leizhen@huawei.com> X-Mailer: git-send-email 2.26.0.windows.1 In-Reply-To: <20211115035721.1909-1-thunder.leizhen@huawei.com> References: <20211115035721.1909-1-thunder.leizhen@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.178.55] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpemm500006.china.huawei.com (7.185.36.236) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org The buf->offset has been assigned to 0 before the copy operation, and it seems odd to readjust its value after the copy is complete. Delete the second 'buf->offset = 0'. Signed-off-by: Zhen Lei --- fs/pipe.c | 1 - 1 file changed, 1 deletion(-) diff --git a/fs/pipe.c b/fs/pipe.c index 302f1e50ce3be1d..7ba11a633c0eeb9 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -536,7 +536,6 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from) break; } ret += copied; - buf->offset = 0; buf->len = copied; if (!iov_iter_count(from))