linux-stable.git/drivers/nvdimm, branch linux-4.9.y

libnvdimm/dimm: Avoid race between probe and available_slots_show()

2021-03-03T16:44:44+00:00

commit 7018c897c2f243d4b5f1b94bc6b4831a7eab80fb upstream

Richard reports that the following test:

(while true; do
     cat /sys/bus/nd/devices/nmem*/available_slots 2>&1 > /dev/null
 done) &

while true; do
     for i in $(seq 0 4); do
         echo nmem$i > /sys/bus/nd/drivers/nvdimm/bind
     done
     for i in $(seq 0 4); do
         echo nmem$i > /sys/bus/nd/drivers/nvdimm/unbind
     done
 done

...fails with a crash signature like:

    divide error: 0000 [#1] SMP KASAN PTI
    RIP: 0010:nd_label_nfree+0x134/0x1a0 [libnvdimm]
    [..]
    Call Trace:
     available_slots_show+0x4e/0x120 [libnvdimm]
     dev_attr_show+0x42/0x80
     ? memset+0x20/0x40
     sysfs_kf_seq_show+0x218/0x410

The root cause is that available_slots_show() consults driver-data, but
fails to synchronize against device-unbind setting up a TOCTOU race to
access uninitialized memory.

Validate driver-data under the device-lock.

Fixes: 4d88a97aa9e8 ("libnvdimm, nvdimm: dimm driver and base libnvdimm device-driver infrastructure")
Cc: 
Cc: Vishal Verma 
Cc: Dave Jiang 
Cc: Ira Weiny 
Cc: Coly Li 
Reported-by: Richard Palethorpe 
Acked-by: Richard Palethorpe 
Signed-off-by: Dan Williams 
[sudip: use device_lock()]
Signed-off-by: Sudip Mukherjee 
Signed-off-by: Greg Kroah-Hartman

block: Move SECTOR_SIZE and SECTOR_SHIFT definitions into

2020-09-12T09:47:36+00:00

commit 233bde21aa43516baa013ef7ac33f3427056db3e upstream.

It happens often while I'm preparing a patch for a block driver that
I'm wondering: is a definition of SECTOR_SIZE and/or SECTOR_SHIFT
available for this driver? Do I have to introduce definitions of these
constants before I can use these constants? To avoid this confusion,
move the existing definitions of SECTOR_SIZE and SECTOR_SHIFT into the
 header file such that these become available for all
block drivers. Make the SECTOR_SIZE definition in the uapi msdos_fs.h
header file conditional to avoid that including that header file after
 causes the compiler to complain about a SECTOR_SIZE
redefinition.

Note: the SECTOR_SIZE / SECTOR_SHIFT / SECTOR_BITS definitions have
not been removed from uapi header files nor from NAND drivers in
which these constants are used for another purpose than converting
block layer offsets and sizes into a number of sectors.

Cc: David S. Miller 
Cc: Mike Snitzer 
Cc: Dan Williams 
Cc: Minchan Kim 
Cc: Nitin Gupta 
Reviewed-by: Sergey Senozhatsky 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Johannes Thumshirn 
Reviewed-by: Martin K. Petersen 
Signed-off-by: Bart Van Assche 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

libnvdimm/btt: Remove unnecessary code in btt_freelist_init

2020-05-27T14:42:00+00:00

[ Upstream commit 2f8c9011151337d0bc106693f272f9bddbccfab2 ]

We call btt_log_read() twice, once to get the 'old' log entry, and again
to get the 'new' entry. However, we have no use for the 'old' entry, so
remove it.

Cc: Dan Williams 
Signed-off-by: Vishal Verma 
Signed-off-by: Dan Williams 
Signed-off-by: Sasha Levin

libnvdimm: Out of bounds read in __nd_ioctl()

2020-04-24T05:59:14+00:00

[ Upstream commit f84afbdd3a9e5e10633695677b95422572f920dc ]

The "cmd" comes from the user and it can be up to 255.  It it's more
than the number of bits in long, it results out of bounds read when we
check test_bit(cmd, &cmd_mask).  The highest valid value for "cmd" is
ND_CMD_CALL (10) so I added a compare against that.

Fixes: 62232e45f4a2 ("libnvdimm: control (ioctl) messages for nvdimm_bus and nvdimm devices")
Signed-off-by: Dan Carpenter 
Link: https://lore.kernel.org/r/20200225162055.amtosfy7m35aivxg@kili.mountain
Signed-off-by: Dan Williams 
Signed-off-by: Sasha Levin

libnvdimm/pfn: fix fsdax-mode namespace info-block zero-fields

2019-08-04T07:33:29+00:00

commit 7e3e888dfc138089f4c15a81b418e88f0978f744 upstream.

At namespace creation time there is the potential for the "expected to
be zero" fields of a 'pfn' info-block to be filled with indeterminate
data.  While the kernel buffer is zeroed on allocation it is immediately
overwritten by nd_pfn_validate() filling it with the current contents of
the on-media info-block location.  For fields like, 'flags' and the
'padding' it potentially means that future implementations can not rely on
those fields being zero.

In preparation to stop using the 'start_pad' and 'end_trunc' fields for
section alignment, arrange for fields that are not explicitly
initialized to be guaranteed zero.  Bump the minor version to indicate
it is safe to assume the 'padding' and 'flags' are zero.  Otherwise,
this corruption is expected to benign since all other critical fields
are explicitly initialized.

Note The cc: stable is about spreading this new policy to as many
kernels as possible not fixing an issue in those kernels.  It is not
until the change titled "libnvdimm/pfn: Stop padding pmem namespaces to
section alignment" where this improper initialization becomes a problem.
So if someone decides to backport "libnvdimm/pfn: Stop padding pmem
namespaces to section alignment" (which is not tagged for stable), make
sure this pre-requisite is flagged.

Link: http://lkml.kernel.org/r/156092356065.979959.6681003754765958296.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: 32ab0a3f5170 ("libnvdimm, pmem: 'struct page' for pmem")
Signed-off-by: Dan Williams 
Tested-by: Aneesh Kumar K.V 	[ppc64]
Cc: 
Cc: David Hildenbrand 
Cc: Jane Chu 
Cc: Jeff Moyer 
Cc: Jérôme Glisse 
Cc: Jonathan Corbet 
Cc: Logan Gunthorpe 
Cc: Michal Hocko 
Cc: Mike Rapoport 
Cc: Oscar Salvador 
Cc: Pavel Tatashin 
Cc: Toshi Kani 
Cc: Vlastimil Babka 
Cc: Wei Yang 
Cc: Jason Gunthorpe 
Cc: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

libnvdimm/namespace: Fix label tracking error

2019-05-31T13:48:11+00:00

commit c4703ce11c23423d4b46e3d59aef7979814fd608 upstream.

Users have reported intermittent occurrences of DIMM initialization
failures due to duplicate allocations of address capacity detected in
the labels, or errors of the form below, both have the same root cause.

    nd namespace1.4: failed to track label: 0
    WARNING: CPU: 17 PID: 1381 at drivers/nvdimm/label.c:863

    RIP: 0010:__pmem_label_update+0x56c/0x590 [libnvdimm]
    Call Trace:
     ? nd_pmem_namespace_label_update+0xd6/0x160 [libnvdimm]
     nd_pmem_namespace_label_update+0xd6/0x160 [libnvdimm]
     uuid_store+0x17e/0x190 [libnvdimm]
     kernfs_fop_write+0xf0/0x1a0
     vfs_write+0xb7/0x1b0
     ksys_write+0x57/0xd0
     do_syscall_64+0x60/0x210

Unfortunately those reports were typically with a busy parallel
namespace creation / destruction loop making it difficult to see the
components of the bug. However, Jane provided a simple reproducer using
the work-in-progress sub-section implementation.

When ndctl is reconfiguring a namespace it may take an existing defunct
/ disabled namespace and reconfigure it with a new uuid and other
parameters. Critically namespace_update_uuid() takes existing address
resources and renames them for the new namespace to use / reconfigure as
it sees fit. The bug is that this rename only happens in the resource
tracking tree. Existing labels with the old uuid are not reaped leading
to a scenario where multiple active labels reference the same span of
address range.

Teach namespace_update_uuid() to flag any references to the old uuid for
reaping at the next label update attempt.

Cc: 
Fixes: bf9bccc14c05 ("libnvdimm: pmem label sets and namespace instantiation")
Link: https://github.com/pmem/ndctl/issues/91
Reported-by: Jane Chu 
Reported-by: Jeff Moyer 
Reported-by: Erwin Tsaur 
Cc: Johannes Thumshirn 
Signed-off-by: Dan Williams 
Signed-off-by: Greg Kroah-Hartman

libnvdimm/btt: Fix a kmemdup failure check

2019-05-16T17:43:41+00:00

[ Upstream commit 486fa92df4707b5df58d6508728bdb9321a59766 ]

In case kmemdup fails, the fix releases resources and returns to
avoid the NULL pointer dereference.

Signed-off-by: Aditya Pakki 
Signed-off-by: Dan Williams 
Signed-off-by: Sasha Levin

libnvdimm/namespace: Fix a potential NULL pointer dereference

2019-05-16T17:43:40+00:00

[ Upstream commit 55c1fc0af29a6c1b92f217b7eb7581a882e0c07c ]

In case kmemdup fails, the fix goes to blk_err to avoid NULL
pointer dereference.

Signed-off-by: Kangjie Lu 
Signed-off-by: Dan Williams 
Signed-off-by: Sasha Levin

libnvdimm: Fix altmap reservation size calculation

2019-03-23T12:19:45+00:00

commit 07464e88365e9236febaca9ed1a2e2006d8bc952 upstream.

Libnvdimm reserves the first 8K of pfn and devicedax namespaces to
store a superblock describing the namespace. This 8K reservation
is contained within the altmap area which the kernel uses for the
vmemmap backing for the pages within the namespace. The altmap
allows for some pages at the start of the altmap area to be reserved
and that mechanism is used to protect the superblock from being
re-used as vmemmap backing.

The number of PFNs to reserve is calculated using:

	PHYS_PFN(SZ_8K)

Which is implemented as:

 #define PHYS_PFN(x) ((unsigned long)((x) >> PAGE_SHIFT))

So on systems where PAGE_SIZE is greater than 8K the reservation
size is truncated to zero and the superblock area is re-used as
vmemmap backing. As a result all the namespace information stored
in the superblock (i.e. if it's a PFN or DAX namespace) is lost
and the namespace needs to be re-created to get access to the
contents.

This patch fixes this by using PFN_UP() rather than PHYS_PFN() to ensure
that at least one page is reserved. On systems with a 4K pages size this
patch should have no effect.

Cc: stable@vger.kernel.org
Cc: Dan Williams 
Fixes: ac515c084be9 ("libnvdimm, pmem, pfn: move pfn setup to the core")
Signed-off-by: Oliver O'Halloran 
Reviewed-by: Vishal Verma 
Signed-off-by: Dan Williams 
Signed-off-by: Greg Kroah-Hartman

libnvdimm/pmem: Honor force_raw for legacy pmem regions

2019-03-23T12:19:45+00:00

commit fa7d2e639cd90442d868dfc6ca1d4cc9d8bf206e upstream.

For recovery, where non-dax access is needed to a given physical address
range, and testing, allow the 'force_raw' attribute to override the
default establishment of a dev_pagemap.

Otherwise without this capability it is possible to end up with a
namespace that can not be activated due to corrupted info-block, and one
that can not be repaired due to a section collision.

Cc: 
Fixes: 004f1afbe199 ("libnvdimm, pmem: direct map legacy pmem by default")
Signed-off-by: Dan Williams 
Signed-off-by: Greg Kroah-Hartman