Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1433350AbdDYXEv (ORCPT ); Tue, 25 Apr 2017 19:04:51 -0400 Received: from g4t3427.houston.hpe.com ([15.241.140.73]:7114 "EHLO g4t3427.houston.hpe.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1433335AbdDYXEr (ORCPT ); Tue, 25 Apr 2017 19:04:47 -0400 From: Toshi Kani To: dan.j.williams@intel.com Cc: vishal.l.verma@intel.com, linux-nvdimm@ml01.01.org, linux-kernel@vger.kernel.org, Toshi Kani Subject: [PATCH] pmem: fix a NULL pointer BUG in nd_pmem_notify Date: Tue, 25 Apr 2017 17:04:13 -0600 Message-Id: <20170425230413.363-1-toshi.kani@hpe.com> X-Mailer: git-send-email 2.9.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2841 Lines: 91 The following BUG was observed when nd_pmem_notify() was called for a BTT device. The use of a pmem_device pointer is not valid with BTT. BUG: unable to handle kernel NULL pointer dereference at 0000000000000030 IP: nd_pmem_notify+0x30/0xf0 [nd_pmem] Call Trace: nd_device_notify+0x40/0x50 child_notify+0x10/0x20 device_for_each_child+0x50/0x90 nd_region_notify+0x20/0x30 nd_device_notify+0x40/0x50 nvdimm_region_notify+0x27/0x30 acpi_nfit_scrub+0x341/0x590 [nfit] process_one_work+0x197/0x450 worker_thread+0x4e/0x4a0 kthread+0x109/0x140 Fix nd_pmem_notify() by setting nd_region and badblocks pointers properly for BTT. Signed-off-by: Toshi Kani Cc: Dan Williams Cc: Vishal Verma --- drivers/nvdimm/pmem.c | 37 +++++++++++++++++++++++++------------ 1 file changed, 25 insertions(+), 12 deletions(-) diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 5b536be..0fc1826 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -388,12 +388,12 @@ static void nd_pmem_shutdown(struct device *dev) static void nd_pmem_notify(struct device *dev, enum nvdimm_event event) { - struct pmem_device *pmem = dev_get_drvdata(dev); - struct nd_region *nd_region = to_region(pmem); + struct nd_region *nd_region; resource_size_t offset = 0, end_trunc = 0; struct nd_namespace_common *ndns; struct nd_namespace_io *nsio; struct resource res; + struct badblocks *bb; if (event != NVDIMM_REVALIDATE_POISON) return; @@ -402,20 +402,33 @@ static void nd_pmem_notify(struct device *dev, enum nvdimm_event event) struct nd_btt *nd_btt = to_nd_btt(dev); ndns = nd_btt->ndns; - } else if (is_nd_pfn(dev)) { - struct nd_pfn *nd_pfn = to_nd_pfn(dev); - struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb; + nd_region = to_nd_region(ndns->dev.parent); + nsio = to_nd_namespace_io(&ndns->dev); + bb = &nsio->bb; + } else { + struct pmem_device *pmem = dev_get_drvdata(dev); - ndns = nd_pfn->ndns; - offset = pmem->data_offset + __le32_to_cpu(pfn_sb->start_pad); - end_trunc = __le32_to_cpu(pfn_sb->end_trunc); - } else - ndns = to_ndns(dev); + nd_region = to_region(pmem); + bb = &pmem->bb; + + if (is_nd_pfn(dev)) { + struct nd_pfn *nd_pfn = to_nd_pfn(dev); + struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb; + + ndns = nd_pfn->ndns; + offset = pmem->data_offset + + __le32_to_cpu(pfn_sb->start_pad); + end_trunc = __le32_to_cpu(pfn_sb->end_trunc); + } else { + ndns = to_ndns(dev); + } + + nsio = to_nd_namespace_io(&ndns->dev); + } - nsio = to_nd_namespace_io(&ndns->dev); res.start = nsio->res.start + offset; res.end = nsio->res.end - end_trunc; - nvdimm_badblocks_populate(nd_region, &pmem->bb, &res); + nvdimm_badblocks_populate(nd_region, bb, &res); } MODULE_ALIAS("pmem");