linux-stable.git/drivers/block, branch v5.4.87

null_blk: Fix zone size initialization

2021-01-06T13:48:37+00:00

commit 0ebcdd702f49aeb0ad2e2d894f8c124a0acc6e23 upstream.

For a null_blk device with zoned mode enabled is currently initialized
with a number of zones equal to the device capacity divided by the zone
size, without considering if the device capacity is a multiple of the
zone size. If the zone size is not a divisor of the capacity, the zones
end up not covering the entire capacity, potentially resulting is out
of bounds accesses to the zone array.

Fix this by adding one last smaller zone with a size equal to the
remainder of the disk capacity divided by the zone size if the capacity
is not a multiple of the zone size. For such smaller last zone, the zone
capacity is also checked so that it does not exceed the smaller zone
size.

Reported-by: Naohiro Aota 
Fixes: ca4b2a011948 ("null_blk: add zone support")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

xen/xenbus: Add 'will_handle' callback support in xenbus_watch_path()

2020-12-30T10:51:46+00:00

commit 2e85d32b1c865bec703ce0c962221a5e955c52c2 upstream.

Some code does not directly make 'xenbus_watch' object and call
'register_xenbus_watch()' but use 'xenbus_watch_path()' instead.  This
commit adds support of 'will_handle' callback in the
'xenbus_watch_path()' and it's wrapper, 'xenbus_watch_pathfmt()'.

This is part of XSA-349

Cc: stable@vger.kernel.org
Signed-off-by: SeongJae Park 
Reported-by: Michael Kurth 
Reported-by: Pawel Wieczorkiewicz 
Reviewed-by: Juergen Gross 
Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

xen-blkback: set ring->xenblkd to NULL after kthread_stop()

2020-12-30T10:51:46+00:00

commit 1c728719a4da6e654afb9cc047164755072ed7c9 upstream.

When xen_blkif_disconnect() is called, the kernel thread behind the
block interface is stopped by calling kthread_stop(ring->xenblkd).
The ring->xenblkd thread pointer being non-NULL determines if the
thread has been already stopped.
Normally, the thread's function xen_blkif_schedule() sets the
ring->xenblkd to NULL, when the thread's main loop ends.

However, when the thread has not been started yet (i.e.
wake_up_process() has not been called on it), the xen_blkif_schedule()
function would not be called yet.

In such case the kthread_stop() call returns -EINTR and the
ring->xenblkd remains dangling.
When this happens, any consecutive call to xen_blkif_disconnect (for
example in frontend_changed() callback) leads to a kernel crash in
kthread_stop() (e.g. NULL pointer dereference in exit_creds()).

This is XSA-350.

Cc:  # 4.12
Fixes: a24fa22ce22a ("xen/blkback: don't use xen_blkif_get() in xen-blkback kthread")
Reported-by: Olivier Benjamin 
Reported-by: Pawel Wieczorkiewicz 
Signed-off-by: Pawel Wieczorkiewicz 
Reviewed-by: Julien Grall 
Reviewed-by: Juergen Gross 
Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

nbd: fix a block_device refcount leak in nbd_release

2020-11-18T18:20:27+00:00

[ Upstream commit 2bd645b2d3f0bacadaa6037f067538e1cd4e42ef ]

bdget_disk needs to be paired with bdput to not leak a reference
on the block device inode.

Fixes: 08ba91ee6e2c ("nbd: Add the nbd NBD_DISCONNECT_ON_CLOSE config flag.")
Signed-off-by: Christoph Hellwig 
Reviewed-by: Josef Bacik 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

nbd: don't update block size after device is started

2020-11-18T18:20:15+00:00

[ Upstream commit b40813ddcd6bf9f01d020804e4cb8febc480b9e4 ]

Mounted NBD device can be resized, one use case is rbd-nbd.

Fix the issue by setting up default block size, then not touch it
in nbd_size_update() any more. This kind of usage is aligned with loop
which has same use case too.

Cc: stable@vger.kernel.org
Fixes: c8a83a6b54d0 ("nbd: Use set_blocksize() to set device blocksize")
Reported-by: lining 
Signed-off-by: Ming Lei 
Cc: Josef Bacik 
Cc: Jan Kara 
Tested-by: lining 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

nbd: make the config put is called before the notifying the waiter

2020-11-05T10:43:22+00:00

[ Upstream commit 87aac3a80af5cbad93e63250e8a1e19095ba0d30 ]

There has one race case for ceph's rbd-nbd tool. When do mapping
it may fail with EBUSY from ioctl(nbd, NBD_DO_IT), but actually
the nbd device has already unmaped.

It dues to if just after the wake_up(), the recv_work() is scheduled
out and defers calling the nbd_config_put(), though the map process
has exited the "nbd->recv_task" is not cleared.

Signed-off-by: Xiubo Li 
Reviewed-by: Josef Bacik 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

xen/blkback: use lateeoi irq binding

2020-11-05T10:43:11+00:00

commit 01263a1fabe30b4d542f34c7e2364a22587ddaf2 upstream.

In order to reduce the chance for the system becoming unresponsive due
to event storms triggered by a misbehaving blkfront use the lateeoi
irq binding for blkback and unmask the event channel only after
processing all pending requests.

As the thread processing requests is used to do purging work in regular
intervals an EOI may be sent only after having received an event. If
there was no pending I/O request flag the EOI as spurious.

This is part of XSA-332.

Cc: stable@vger.kernel.org
Reported-by: Julien Grall 
Signed-off-by: Juergen Gross 
Reviewed-by: Jan Beulich 
Reviewed-by: Wei Liu 
Signed-off-by: Greg Kroah-Hartman

rbd: require global CAP_SYS_ADMIN for mapping and unmapping

2020-09-17T11:47:53+00:00

commit f44d04e696feaf13d192d942c4f14ad2e117065a upstream.

It turns out that currently we rely only on sysfs attribute
permissions:

  $ ll /sys/bus/rbd/{add*,remove*}
  --w------- 1 root root 4096 Sep  3 20:37 /sys/bus/rbd/add
  --w------- 1 root root 4096 Sep  3 20:37 /sys/bus/rbd/add_single_major
  --w------- 1 root root 4096 Sep  3 20:37 /sys/bus/rbd/remove
  --w------- 1 root root 4096 Sep  3 20:38 /sys/bus/rbd/remove_single_major

This means that images can be mapped and unmapped (i.e. block devices
can be created and deleted) by a UID 0 process even after it drops all
privileges or by any process with CAP_DAC_OVERRIDE in its user namespace
as long as UID 0 is mapped into that user namespace.

Be consistent with other virtual block devices (loop, nbd, dm, md, etc)
and require CAP_SYS_ADMIN in the initial user namespace for mapping and
unmapping, and also for dumping the configuration string and refreshing
the image header.

Cc: stable@vger.kernel.org
Signed-off-by: Ilya Dryomov 
Reviewed-by: Jeff Layton 
Signed-off-by: Greg Kroah-Hartman

nbd: restore default timeout when setting it to zero

2020-09-09T17:12:22+00:00

[ Upstream commit acb19e17c5134dd78668c429ecba5b481f038e6a ]

If we configured io timeout of nbd0 to 100s. Later after we
finished using it, we configured nbd0 again and set the io
timeout to 0. We expect it would timeout after 30 seconds
and keep retry. But in fact we could not change the timeout
when we set it to 0. the timeout is still the original 100s.

So change the timeout to default 30s when we set it to zero.
It also behaves same as commit 2da22da57348 ("nbd: fix zero
cmd timeout handling v2").

It becomes more important if we were reconfigure a nbd device
and the io timeout it set to zero. Because it could take 30s
to detect the new socket and thus io could be completed more
quickly compared to 100s.

Signed-off-by: Hou Pu 
Reviewed-by: Josef Bacik 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: loop: set discard granularity and alignment for block device backed loop

2020-09-03T09:27:01+00:00

commit bcb21c8cc9947286211327d663ace69f07d37a76 upstream.

In case of block device backend, if the backend supports write zeros, the
loop device will set queue flag of QUEUE_FLAG_DISCARD. However,
limits.discard_granularity isn't setup, and this way is wrong,
see the following description in Documentation/ABI/testing/sysfs-block:

	A discard_granularity of 0 means that the device does not support
	discard functionality.

Especially 9b15d109a6b2 ("block: improve discard bio alignment in
__blkdev_issue_discard()") starts to take q->limits.discard_granularity
for computing max discard sectors. And zero discard granularity may cause
kernel oops, or fail discard request even though the loop queue claims
discard support via QUEUE_FLAG_DISCARD.

Fix the issue by setup discard granularity and alignment.

Fixes: c52abf563049 ("loop: Better discard support for block devices")
Signed-off-by: Ming Lei 
Reviewed-by: Christoph Hellwig 
Acked-by: Coly Li 
Cc: Hannes Reinecke 
Cc: Xiao Ni 
Cc: Martin K. Petersen 
Cc: Evan Green 
Cc: Gwendal Grignou 
Cc: Chaitanya Kulkarni 
Cc: Andrzej Pietrasiewicz 
Cc: Christoph Hellwig 
Cc: 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman