From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:39620 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933197AbeBUNDj (ORCPT ); Wed, 21 Feb 2018 08:03:39 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michal Kalderon , Chuck Lever , Anna Schumaker Subject: [PATCH 4.14 129/167] xprtrdma: Fix BUG after a device removal Date: Wed, 21 Feb 2018 13:49:00 +0100 Message-Id: <20180221124531.669976701@linuxfoundation.org> In-Reply-To: <20180221124524.639039577@linuxfoundation.org> References: <20180221124524.639039577@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chuck Lever commit e89e8d8fcdc6751e86ccad794b052fe67e6ad619 upstream. Michal Kalderon reports a BUG that occurs just after device removal: [ 169.112490] rpcrdma: removing device qedr0 for 192.168.110.146:20049 [ 169.143909] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 [ 169.181837] IP: rpcrdma_dma_unmap_regbuf+0xa/0x60 [rpcrdma] The RPC/RDMA client transport attempts to allocate some resources on demand. Registered buffers are one such resource. These are allocated (or re-allocated) by xprt_rdma_allocate to hold RPC Call and Reply messages. A hardware resource is associated with each of these buffers, as they can be used for a Send or Receive Work Request. If a device is removed from under an NFS/RDMA mount, the transport layer is responsible for releasing all hardware resources before the device can be finally unplugged. A BUG results when the NFS mount hasn't yet seen much activity: the transport tries to release resources that haven't yet been allocated. rpcrdma_free_regbuf() already checks for this case, so just move that check to cover the DEVICE_REMOVAL case as well. Reported-by: Michal Kalderon Fixes: bebd031866ca ("xprtrdma: Support unplugging an HCA ...") Signed-off-by: Chuck Lever Tested-by: Michal Kalderon Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Anna Schumaker Signed-off-by: Greg Kroah-Hartman --- net/sunrpc/xprtrdma/verbs.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -1331,6 +1331,9 @@ __rpcrdma_dma_map_regbuf(struct rpcrdma_ static void rpcrdma_dma_unmap_regbuf(struct rpcrdma_regbuf *rb) { + if (!rb) + return; + if (!rpcrdma_regbuf_is_mapped(rb)) return; @@ -1346,9 +1349,6 @@ rpcrdma_dma_unmap_regbuf(struct rpcrdma_ void rpcrdma_free_regbuf(struct rpcrdma_regbuf *rb) { - if (!rb) - return; - rpcrdma_dma_unmap_regbuf(rb); kfree(rb); }