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=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 03749C2D0DB for ; Sun, 26 Jan 2020 14:27:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CB07E20720 for ; Sun, 26 Jan 2020 14:27:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580048830; bh=hkEzVIDNhPaDMZe0s+LhEP+uEoazk1z54GRsqqQIIjg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Y7wJJdGCBo/LHwGY5zlDEtT0tuxwHdZ0MwZCx31iwXCMi+cmqiUl6kRUSoVGkQpuJ H6Q2VTcMPigZ72XbsiTRZsuVCYUAwmOmqP+Bt16n4VZ2WNs18yNoEUC+VkcO0MoAyp bhvmjExXVN9p2BxHk/Q23uxHoiuZHokcVYhSpmMA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387430AbgAZO1K (ORCPT ); Sun, 26 Jan 2020 09:27:10 -0500 Received: from mail.kernel.org ([198.145.29.99]:42694 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387401AbgAZO1K (ORCPT ); Sun, 26 Jan 2020 09:27:10 -0500 Received: from localhost (unknown [193.47.165.251]) (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 07E1220708; Sun, 26 Jan 2020 14:27:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1580048829; bh=hkEzVIDNhPaDMZe0s+LhEP+uEoazk1z54GRsqqQIIjg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=P/c6pik9MNJdeRHOGdoyGBiKKNi6+vuXjkb8nFZHB6Q5Lg7bmQOhXaJYTsKG6kywB ljM+dp/UZEbufica0hewTY+imVBTtmSXnA4ktsIPMgAtHbOz0lFD4ofh4R7BFOBC2G ldv/I8kah7+wslrCHkZ8lL4+Xi3ytmzth+Gpzquk= From: Leon Romanovsky To: Doug Ledford , Jason Gunthorpe Cc: Leon Romanovsky , RDMA mailing list , Parav Pandit Subject: [PATCH rdma-next 1/7] RDMA/cma: Fix unbalanced cm_id reference count during address resolve Date: Sun, 26 Jan 2020 16:26:46 +0200 Message-Id: <20200126142652.104803-2-leon@kernel.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200126142652.104803-1-leon@kernel.org> References: <20200126142652.104803-1-leon@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org From: Parav Pandit Below cited commit missed to consider AF_IB and loopback code flow in rdma_resolve_addr(). This leads to unbalanced cm_id refcount in cma_work_handler() which puts the refcount which was not incremented in rdma_resolve_addr(). 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 resolve work item. Fixes: 722c7b2bfead ("RDMA/{cma, core}: Avoid callback on rdma_addr_cancel()") Signed-off-by: Parav Pandit Signed-off-by: Leon Romanovsky --- 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 55a9afacfedd..72f032160c4b 100644 --- a/drivers/infiniband/core/cma.c +++ b/drivers/infiniband/core/cma.c @@ -3148,6 +3148,7 @@ 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; @@ -3174,6 +3175,7 @@ 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; -- 2.24.1