From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:35798 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2992735AbbHHWAc (ORCPT ); Sat, 8 Aug 2015 18:00:32 -0400 Subject: Patch "rds: rds_ib_device.refcount overflow" has been added to the 3.14-stable tree To: wen.gang.wang@oracle.com, dledford@redhat.com, gregkh@linuxfoundation.org, haggaie@mellanox.com Cc: , From: Date: Sat, 08 Aug 2015 15:00:31 -0700 Message-ID: <14390712311723@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled rds: rds_ib_device.refcount overflow to the 3.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: rds-rds_ib_device.refcount-overflow.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 4fabb59449aa44a585b3603ffdadd4c5f4d0c033 Mon Sep 17 00:00:00 2001 From: Wengang Wang Date: Mon, 6 Jul 2015 14:35:11 +0800 Subject: rds: rds_ib_device.refcount overflow From: Wengang Wang commit 4fabb59449aa44a585b3603ffdadd4c5f4d0c033 upstream. Fixes: 3e0249f9c05c ("RDS/IB: add refcount tracking to struct rds_ib_device") There lacks a dropping on rds_ib_device.refcount in case rds_ib_alloc_fmr failed(mr pool running out). this lead to the refcount overflow. A complain in line 117(see following) is seen. From vmcore: s_ib_rdma_mr_pool_depleted is 2147485544 and rds_ibdev->refcount is -2147475448. That is the evidence the mr pool is used up. so rds_ib_alloc_fmr is very likely to return ERR_PTR(-EAGAIN). 115 void rds_ib_dev_put(struct rds_ib_device *rds_ibdev) 116 { 117 BUG_ON(atomic_read(&rds_ibdev->refcount) <= 0); 118 if (atomic_dec_and_test(&rds_ibdev->refcount)) 119 queue_work(rds_wq, &rds_ibdev->free_work); 120 } fix is to drop refcount when rds_ib_alloc_fmr failed. Signed-off-by: Wengang Wang Reviewed-by: Haggai Eran Signed-off-by: Doug Ledford Signed-off-by: Greg Kroah-Hartman --- net/rds/ib_rdma.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/net/rds/ib_rdma.c +++ b/net/rds/ib_rdma.c @@ -759,8 +759,10 @@ void *rds_ib_get_mr(struct scatterlist * } ibmr = rds_ib_alloc_fmr(rds_ibdev); - if (IS_ERR(ibmr)) + if (IS_ERR(ibmr)) { + rds_ib_dev_put(rds_ibdev); return ibmr; + } ret = rds_ib_map_fmr(rds_ibdev, ibmr, sg, nents); if (ret == 0) Patches currently in stable-queue which might be from wen.gang.wang@oracle.com are queue-3.14/rds-rds_ib_device.refcount-overflow.patch