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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 8E5B9C388F9 for ; Tue, 27 Oct 2020 15:10:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3609C20657 for ; Tue, 27 Oct 2020 15:10:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603811441; bh=QZrPLNJpuWsmNkV0nyFp3PfJ1PGCgZCjAPJZR4EMZPU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=oQR4cjOmWiCE/TpVWbrPkb4E3YVEkcA0xxkTnyx+4evviALfbuXNqFH8FVHro6iLk pstvohdHf3vvicSTnmYWCDwzh5whT+DYIUveXZh7ydPD9YTAg2eLahfLt7nmymItTy x44eYYO1FU+BpVbJpFZt3PbaKeVc2Uhfm6IcOePo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1794223AbgJ0PKi (ORCPT ); Tue, 27 Oct 2020 11:10:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:37202 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1789789AbgJ0PCx (ORCPT ); Tue, 27 Oct 2020 11:02:53 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A81AC2071A; Tue, 27 Oct 2020 15:02:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603810973; bh=QZrPLNJpuWsmNkV0nyFp3PfJ1PGCgZCjAPJZR4EMZPU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=z32WtevVIoNkp2ApYwWlR0nJcrBV45g421+MnDeWl4/UGqW+RszUGMBwQRoweVZzJ YOLLbPhvdIzocaCdKhZGqgXGMpPUe0/+ZD0KI7mDFNfLZCkSt4mfeWj89aZv2/D3X3 QdRim7bDmrauPpur5ULVyxt2wET1iZ05aGCSJaaM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Leon Romanovsky , Jason Gunthorpe , Sasha Levin Subject: [PATCH 5.8 329/633] RDMA/ucma: Fix locking for ctx->events_reported Date: Tue, 27 Oct 2020 14:51:12 +0100 Message-Id: <20201027135538.113663554@linuxfoundation.org> X-Mailer: git-send-email 2.29.1 In-Reply-To: <20201027135522.655719020@linuxfoundation.org> References: <20201027135522.655719020@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: Jason Gunthorpe [ Upstream commit 98837c6c3d7285f6eca86480b6f7fac6880e27a8 ] This value is locked under the file->mut, ensure it is held whenever touching it. The case in ucma_migrate_id() is a race, while in ucma_free_uctx() it is already not possible for the write side to run, the movement is just for clarity. Fixes: 88314e4dda1e ("RDMA/cma: add support for rdma_migrate_id()") Link: https://lore.kernel.org/r/20200818120526.702120-10-leon@kernel.org Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin --- drivers/infiniband/core/ucma.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c index d03dacaef7880..cf283b70bf877 100644 --- a/drivers/infiniband/core/ucma.c +++ b/drivers/infiniband/core/ucma.c @@ -586,6 +586,7 @@ static int ucma_free_ctx(struct ucma_context *ctx) list_move_tail(&uevent->list, &list); } list_del(&ctx->list); + events_reported = ctx->events_reported; mutex_unlock(&ctx->file->mut); list_for_each_entry_safe(uevent, tmp, &list, list) { @@ -595,7 +596,6 @@ static int ucma_free_ctx(struct ucma_context *ctx) kfree(uevent); } - events_reported = ctx->events_reported; mutex_destroy(&ctx->mutex); kfree(ctx); return events_reported; @@ -1678,7 +1678,9 @@ static ssize_t ucma_migrate_id(struct ucma_file *new_file, cur_file = ctx->file; if (cur_file == new_file) { + mutex_lock(&cur_file->mut); resp.events_reported = ctx->events_reported; + mutex_unlock(&cur_file->mut); goto response; } -- 2.25.1