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Patch "libnvdimm, region: fix flush hint detection crash" has been added to the 4.10-stable tree

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

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

libnvdimm, region: fix flush hint detection crash

to the 4.10-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-region-fix-flush-hint-detection-crash.patch
and it can be found in the queue-4.10 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 bc042fdfbb92b5b13421316b4548e2d6e98eed37 Mon Sep 17 00:00:00 2001

From: Dan Williams <[email protected]>
Date: Mon, 24 Apr 2017 15:43:05 -0700
Subject: libnvdimm, region: fix flush hint detection crash

From: Dan Williams <[email protected]>

commit bc042fdfbb92b5b13421316b4548e2d6e98eed37 upstream.

In the case where a dimm does not have any associated flush hints the ndrd->flush_wpq array may be uninitialized leading to crashes with the following signature:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
 IP: region_visible+0x10f/0x160 [libnvdimm]

 Call Trace:
  internal_create_group+0xbe/0x2f0
  sysfs_create_groups+0x40/0x80
  device_add+0x2d8/0x650
  nd_async_device_register+0x12/0x40 [libnvdimm]
  async_run_entry_fn+0x39/0x170
  process_one_work+0x212/0x6c0
  ? process_one_work+0x197/0x6c0
  worker_thread+0x4e/0x4a0
  kthread+0x10c/0x140
  ? process_one_work+0x6c0/0x6c0
  ? kthread_create_on_node+0x60/0x60
  ret_from_fork+0x31/0x40
Reviewed-by Jeff Moyer <[email protected]>
Fixes f284a4f23752 ("libnvdimm: introduce nvdimm_flush() and nvdimm_has_flush()")
Signed-off-by Dan Williams <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 drivers/nvdimm/region_devs.c |   11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)
drivers/nvdimm/region_devs.c +7 -4
@@ -968,17 +968,20 @@ EXPORT_SYMBOL_GPL(nvdimm_flush);
  */
 int nvdimm_has_flush(struct nd_region *nd_region)
 {
-	struct nd_region_data *ndrd = dev_get_drvdata(&nd_region->dev);
 	int i;
 
 	/* no nvdimm == flushing capability unknown */
 	if (nd_region->ndr_mappings == 0)
 		return -ENXIO;
 
-	for (i = 0; i < nd_region->ndr_mappings; i++)
-		/* flush hints present, flushing required */
-		if (ndrd_get_flush_wpq(ndrd, i, 0))
+	for (i = 0; i < nd_region->ndr_mappings; i++) {
+		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
+		struct nvdimm *nvdimm = nd_mapping->nvdimm;
+
+		/* flush hints present / available */
+		if (nvdimm->num_flush)
 			return 1;
+	}
 
 	/*
 	 * The platform defines dimm devices without hints, assume

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

queue-4.10/libnvdimm-fix-nvdimm_bus_lock-vs-device_lock-ordering.patch queue-4.10/x86-pmem-fix-cache-flushing-for-iovec-write-8-bytes.patch queue-4.10/dax-prevent-invalidation-of-mapped-dax-entries.patch queue-4.10/libnvdimm-region-fix-flush-hint-detection-crash.patch queue-4.10/libnvdimm-pfn-fix-npfns-vs-section-alignment.patch queue-4.10/libnvdimm-pmem-fix-a-null-pointer-bug-in-nd_pmem_notify.patch queue-4.10/device-dax-fix-cdev-leak.patch queue-4.10/device-dax-fix-sysfs-attribute-deadlock.patch queue-4.10/mm-fix-data-corruption-due-to-stale-mmap-reads.patch