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=ham 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 75CE7C4363A for ; Tue, 27 Oct 2020 17:58:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 264AE21D42 for ; Tue, 27 Oct 2020 17:58:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603821522; bh=08Ap5+CQ+PwcSqQo1g5EJTDXaeEm0rGK0rR/KRrz96U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=mlIqyNznW+mJaPSa8v6nISuzVzwnzFyFn8L4JfpaUnDnGTvJvlGGyol2+/2YDud6M t9vnS72R2T9FB49DDMcaptHuM475c4ryVzwQQbpG417PHPGv6n0SxIV8N51/Lgbfb5 iWsWkErPIZXc8MO5rPtYjCKgKa4Iz/QVAQza8TJc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1823567AbgJ0R6k (ORCPT ); Tue, 27 Oct 2020 13:58:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:47080 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2901094AbgJ0OW2 (ORCPT ); Tue, 27 Oct 2020 10:22:28 -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 6C0D720727; Tue, 27 Oct 2020 14:22:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603808548; bh=08Ap5+CQ+PwcSqQo1g5EJTDXaeEm0rGK0rR/KRrz96U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0dwsU3QfrEn9IC9qFtsv+F1FGyGhrcgR0iuF6lwevRVkrpnfz9TFmtvcvrc4MDD2V 5DElWhpblvNwdzlZa4mIKwKq/86aqhUsIwKxDyk6Vgb2fRnSuSKChoR3zWwN45WaBk 5AID06Rs1Bz5iDi7qwUtgkmfADOKjqYgQCzikiKI= 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 4.19 133/264] RDMA/ucma: Fix locking for ctx->events_reported Date: Tue, 27 Oct 2020 14:53:11 +0100 Message-Id: <20201027135436.933086906@linuxfoundation.org> X-Mailer: git-send-email 2.29.1 In-Reply-To: <20201027135430.632029009@linuxfoundation.org> References: <20201027135430.632029009@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 2acc30c3d5b2d..0c095c8c0ac5b 100644 --- a/drivers/infiniband/core/ucma.c +++ b/drivers/infiniband/core/ucma.c @@ -588,6 +588,7 @@ 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) { @@ -597,7 +598,6 @@ 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; @@ -1644,7 +1644,9 @@ 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