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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 320C7C3B1B2 for ; Fri, 14 Feb 2020 18:03:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 093C920848 for ; Fri, 14 Feb 2020 18:03:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581703413; bh=FBM1rzf7DLSMvUAaC3i8DcmuGknUjHJ5lhPV/cxqBRI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=S9/y90RLdJTFyCNjJXh0n5pcTem1esuP0DxmpceIij3oghfOaJ5gpMsFbadUV3MEz Vl4PQBKCaqm/4wTU0sAEa1iG2/hvfrGS+9MS0msXWiPEBLQh8ct7S+tDMAw6RTcT2x q8dEGIExXVDI8X3jk3e/zzl1TQQ+TqBaYuSfmwJs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387576AbgBNPzn (ORCPT ); Fri, 14 Feb 2020 10:55:43 -0500 Received: from mail.kernel.org ([198.145.29.99]:36976 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387552AbgBNPzm (ORCPT ); Fri, 14 Feb 2020 10:55:42 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3C5C124676; Fri, 14 Feb 2020 15:55:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581695742; bh=FBM1rzf7DLSMvUAaC3i8DcmuGknUjHJ5lhPV/cxqBRI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mkzRLZAPYmYdVB++6f9GcrEOUF5motCV8VEPiYhywN2kvV3X/mjtKwAW/y3X6PpZq VQJ1lyMtW/V9blgrQQmIwNWuilGtAGNnrCl8Cb3s/WRPwlA1lIZumeHDlBGdtMDkxc Qi3QgUcwuF6bwWHTzn/QNvGk9FI6UsvO/eM8LCDw= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jason Gunthorpe , Yishai Hadas , =?UTF-8?q?H=C3=A5kon=20Bugge?= , Sasha Levin , linux-rdma@vger.kernel.org Subject: [PATCH AUTOSEL 5.5 314/542] RDMA/core: Fix locking in ib_uverbs_event_read Date: Fri, 14 Feb 2020 10:45:06 -0500 Message-Id: <20200214154854.6746-314-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200214154854.6746-1-sashal@kernel.org> References: <20200214154854.6746-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: Jason Gunthorpe [ Upstream commit 14e23bd6d22123f6f3b2747701fa6cd4c6d05873 ] This should not be using ib_dev to test for disassociation, during disassociation is_closed is set under lock and the waitq is triggered. Instead check is_closed and be sure to re-obtain the lock to test the value after the wait_event returns. Fixes: 036b10635739 ("IB/uverbs: Enable device removal when there are active user space applications") Link: https://lore.kernel.org/r/1578504126-9400-12-git-send-email-yishaih@mellanox.com Signed-off-by: Yishai Hadas Reviewed-by: Håkon Bugge Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin --- drivers/infiniband/core/uverbs_main.c | 32 ++++++++++++--------------- 1 file changed, 14 insertions(+), 18 deletions(-) diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c index 970d8e31dd658..8f5de4dcad97c 100644 --- a/drivers/infiniband/core/uverbs_main.c +++ b/drivers/infiniband/core/uverbs_main.c @@ -220,7 +220,6 @@ void ib_uverbs_release_file(struct kref *ref) } static ssize_t ib_uverbs_event_read(struct ib_uverbs_event_queue *ev_queue, - struct ib_uverbs_file *uverbs_file, struct file *filp, char __user *buf, size_t count, loff_t *pos, size_t eventsz) @@ -238,19 +237,16 @@ static ssize_t ib_uverbs_event_read(struct ib_uverbs_event_queue *ev_queue, if (wait_event_interruptible(ev_queue->poll_wait, (!list_empty(&ev_queue->event_list) || - /* The barriers built into wait_event_interruptible() - * and wake_up() guarentee this will see the null set - * without using RCU - */ - !uverbs_file->device->ib_dev))) + ev_queue->is_closed))) return -ERESTARTSYS; + spin_lock_irq(&ev_queue->lock); + /* If device was disassociated and no event exists set an error */ - if (list_empty(&ev_queue->event_list) && - !uverbs_file->device->ib_dev) + if (list_empty(&ev_queue->event_list) && ev_queue->is_closed) { + spin_unlock_irq(&ev_queue->lock); return -EIO; - - spin_lock_irq(&ev_queue->lock); + } } event = list_entry(ev_queue->event_list.next, struct ib_uverbs_event, list); @@ -285,8 +281,7 @@ static ssize_t ib_uverbs_async_event_read(struct file *filp, char __user *buf, { struct ib_uverbs_async_event_file *file = filp->private_data; - return ib_uverbs_event_read(&file->ev_queue, file->uverbs_file, filp, - buf, count, pos, + return ib_uverbs_event_read(&file->ev_queue, filp, buf, count, pos, sizeof(struct ib_uverbs_async_event_desc)); } @@ -296,9 +291,8 @@ static ssize_t ib_uverbs_comp_event_read(struct file *filp, char __user *buf, struct ib_uverbs_completion_event_file *comp_ev_file = filp->private_data; - return ib_uverbs_event_read(&comp_ev_file->ev_queue, - comp_ev_file->uobj.ufile, filp, - buf, count, pos, + return ib_uverbs_event_read(&comp_ev_file->ev_queue, filp, buf, count, + pos, sizeof(struct ib_uverbs_comp_event_desc)); } @@ -321,7 +315,9 @@ static __poll_t ib_uverbs_event_poll(struct ib_uverbs_event_queue *ev_queue, static __poll_t ib_uverbs_async_event_poll(struct file *filp, struct poll_table_struct *wait) { - return ib_uverbs_event_poll(filp->private_data, filp, wait); + struct ib_uverbs_async_event_file *file = filp->private_data; + + return ib_uverbs_event_poll(&file->ev_queue, filp, wait); } static __poll_t ib_uverbs_comp_event_poll(struct file *filp, @@ -335,9 +331,9 @@ static __poll_t ib_uverbs_comp_event_poll(struct file *filp, static int ib_uverbs_async_event_fasync(int fd, struct file *filp, int on) { - struct ib_uverbs_event_queue *ev_queue = filp->private_data; + struct ib_uverbs_async_event_file *file = filp->private_data; - return fasync_helper(fd, filp, on, &ev_queue->async_queue); + return fasync_helper(fd, filp, on, &file->ev_queue.async_queue); } static int ib_uverbs_comp_event_fasync(int fd, struct file *filp, int on) -- 2.20.1