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Patch "libnvdimm, pmem: fix a NULL pointer BUG in nd_pmem_notify" has been added to the 4.11-stable tree

PATCH [email protected] 1 participant 1 message May 18, 2017

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Stable branch libnvdimm: non-volatile memory device libnvdimm pmem: persistent memory driver
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This is a note to let you know that I've just added the patch titled

libnvdimm, pmem: fix a NULL pointer BUG in nd_pmem_notify

to the 4.11-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:
libnvdimm-pmem-fix-a-null-pointer-bug-in-nd_pmem_notify.patch
and it can be found in the queue-4.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From b2518c78ce76896f0f8f7940bf02104b227e1709 Mon Sep 17 00:00:00 2001

From: Toshi Kani <[email protected]>
Date: Tue, 25 Apr 2017 17:04:13 -0600
Subject: libnvdimm, pmem: fix a NULL pointer BUG in nd_pmem_notify

From: Toshi Kani <[email protected]>

commit b2518c78ce76896f0f8f7940bf02104b227e1709 upstream.

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.

Cc Vishal Verma <[email protected]>
Fixes 719994660c24 ("libnvdimm: async notification support")
Signed-off-by Toshi Kani <[email protected]>
Signed-off-by Dan Williams <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 drivers/nvdimm/pmem.c |   39 ++++++++++++++++++++++++++-------------
 1 file changed, 26 insertions(+), 13 deletions(-)
drivers/nvdimm/pmem.c +26 -13
@@ -388,12 +388,12 @@ static void nd_pmem_shutdown(struct devi
 
 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
 		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;
-
-		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_nd_region(ndns->dev.parent);
+		nsio = to_nd_namespace_io(&ndns->dev);
+		bb = &nsio->bb;
+	} else {
+		struct pmem_device *pmem = dev_get_drvdata(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");

Patches currently in stable-queue which might be from [email protected] are

queue-4.11/libnvdimm-pmem-fix-a-null-pointer-bug-in-nd_pmem_notify.patch