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 8C0BAC3B1B7 for ; Fri, 14 Feb 2020 18:16:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6292B217F4 for ; Fri, 14 Feb 2020 18:16:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581704196; bh=PujbNvqkvyrzZobB4pxyCIUog3O22ilzl8UACEUWRV4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0XQyUz/q0YR9m66OpI3yVGhmfPi/Gp7caC/r37sOs+43gH1v1Pt0IRf83nhmwJreF D0yr8Kb6JJAvXPAX6vs9VuYwH9oVzfk/yVrC1XFHrEKUuGMp3lqf+RigssCQh5DzGc rltVl0P9cjIkaJSEMWCbLKHmADIaeHviY9MGCA0Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730786AbgBNPva (ORCPT ); Fri, 14 Feb 2020 10:51:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:56526 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730780AbgBNPva (ORCPT ); Fri, 14 Feb 2020 10:51:30 -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 2416F2467E; Fri, 14 Feb 2020 15:51:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581695489; bh=PujbNvqkvyrzZobB4pxyCIUog3O22ilzl8UACEUWRV4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d2yVdn8h2na2gMl4u4i4KnAPTBYK5n9gIfL4e4X3c0LJIdzM3F4lNUTputBqfb5vo og9v0Z06HRJ5Ez+p+Fyz+hnAm2nWWjp2GEIZdhIJ6fKuxBVhw4AlJ997wXunA2G9+2 O3CQcfHnBU0CKC2XDc/A6VvjwVKW1tos2HifMqwE= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Parav Pandit , Leon Romanovsky , Jason Gunthorpe , Sasha Levin , linux-rdma@vger.kernel.org Subject: [PATCH AUTOSEL 5.5 119/542] RDMA/cma: Fix unbalanced cm_id reference count during address resolve Date: Fri, 14 Feb 2020 10:41:51 -0500 Message-Id: <20200214154854.6746-119-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 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Parav Pandit [ Upstream commit b4fb4cc5ba83b20dae13cef116c33648e81d2f44 ] Below commit missed the AF_IB and loopback code flow in rdma_resolve_addr(). This leads to an unbalanced cm_id refcount in cma_work_handler() which puts the refcount which was not incremented prior to queuing the work. A call trace is observed with such code flow: BUG: unable to handle kernel NULL pointer dereference at (null) [] __mutex_lock_slowpath+0x166/0x1d0 [] mutex_lock+0x1f/0x2f [] cma_work_handler+0x25/0xa0 [] process_one_work+0x17f/0x440 [] worker_thread+0x126/0x3c0 Hence, hold the cm_id reference when scheduling the resolve work item. Fixes: 722c7b2bfead ("RDMA/{cma, core}: Avoid callback on rdma_addr_cancel()") Link: https://lore.kernel.org/r/20200126142652.104803-2-leon@kernel.org Signed-off-by: Parav Pandit Signed-off-by: Leon Romanovsky Reviewed-by: Jason Gunthorpe Signed-off-by: Jason Gunthorpe Signed-off-by: Sasha Levin --- drivers/infiniband/core/cma.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c index 43a6f07e0afe2..af1afc17b8bdf 100644 --- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -3118,6 +3118,7 @@ static int cma_resolve_loopback(struct rdma_id_private *id_priv) rdma_addr_get_sgid(&id_priv->id.route.addr.dev_addr, &gid); rdma_addr_set_dgid(&id_priv->id.route.addr.dev_addr, &gid); + atomic_inc(&id_priv->refcount); cma_init_resolve_addr_work(work, id_priv); queue_work(cma_wq, &work->work); return 0; @@ -3144,6 +3145,7 @@ static int cma_resolve_ib_addr(struct rdma_id_private *id_priv) rdma_addr_set_dgid(&id_priv->id.route.addr.dev_addr, (union ib_gid *) &(((struct sockaddr_ib *) &id_priv->id.route.addr.dst_addr)->sib_addr)); + atomic_inc(&id_priv->refcount); cma_init_resolve_addr_work(work, id_priv); queue_work(cma_wq, &work->work); return 0; -- 2.20.1