<feed xmlns='http://www.w3.org/2005/Atom'>
<title>blackbird-op-linux/drivers/nvme, branch v5.3</title>
<subtitle>Blackbird™ Linux sources for OpenPOWER</subtitle>
<id>https://git.raptorcs.com/git/blackbird-op-linux/atom?h=v5.3</id>
<link rel='self' href='https://git.raptorcs.com/git/blackbird-op-linux/atom?h=v5.3'/>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/'/>
<updated>2019-08-20T17:02:10+00:00</updated>
<entry>
<title>nvme: Add quirk for LiteON CL1 devices running FW 22301111</title>
<updated>2019-08-20T17:02:10+00:00</updated>
<author>
<name>Mario Limonciello</name>
<email>mario.limonciello@dell.com</email>
</author>
<published>2019-08-16T20:16:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/commit/?id=cb32de1b7e2591f844f18a5513fde8e2bd49bce0'/>
<id>urn:sha1:cb32de1b7e2591f844f18a5513fde8e2bd49bce0</id>
<content type='text'>
One of the components in LiteON CL1 device has limitations that
can be encountered based upon boundary race conditions using the
nvme bus specific suspend to idle flow.

When this situation occurs the drive doesn't resume properly from
suspend-to-idle.

LiteON has confirmed this problem and fixed in the next firmware
version.  As this firmware is already in the field, avoid running
nvme specific suspend to idle flow.

Fixes: d916b1be94b6 ("nvme-pci: use host managed power state for suspend")
Link: http://lists.infradead.org/pipermail/linux-nvme/2019-July/thread.html
Signed-off-by: Mario Limonciello &lt;mario.limonciello@dell.com&gt;
Signed-off-by: Charles Hyde &lt;charles.hyde@dellteam.com&gt;
Reviewed-by: Keith Busch &lt;kbusch@kernel.org&gt;
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
</entry>
<entry>
<title>nvme: Fix cntlid validation when not using NVMEoF</title>
<updated>2019-08-20T17:02:10+00:00</updated>
<author>
<name>Guilherme G. Piccoli</name>
<email>gpiccoli@canonical.com</email>
</author>
<published>2019-08-14T14:26:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/commit/?id=a89fcca8185633993018dc081d6b021d005e6d0b'/>
<id>urn:sha1:a89fcca8185633993018dc081d6b021d005e6d0b</id>
<content type='text'>
Commit 1b1031ca63b2 ("nvme: validate cntlid during controller initialisation")
introduced a validation for controllers with duplicate cntlid that runs
on nvme_init_subsystem(). The problem is that the validation relies on
ctrl-&gt;cntlid, and this value is assigned (from id_ctrl value) after the
call for nvme_init_subsystem() in nvme_init_identify() for non-fabrics
scenario. That leads to ctrl-&gt;cntlid always being 0 in case we have a
physical set of controllers in the same subsystem.

This patch fixes that by loading the discovered cntlid id_ctrl value into
ctrl-&gt;cntlid before the subsystem initialization, only for the non-fabrics
case. The patch was tested with emulated nvme devices (qemu) having two
controllers in a single subsystem. Without the patch, we couldn't make
it work failing in the duplicate check; when running with the patch, we
could see the subsystem holding both controllers.

For the fabrics case we see ctrl-&gt;cntlid has a more intricate relation
with the admin connect, so we didn't change that.

Fixes: 1b1031ca63b2 ("nvme: validate cntlid during controller initialisation")
Signed-off-by: Guilherme G. Piccoli &lt;gpiccoli@canonical.com&gt;
Reviewed-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
</entry>
<entry>
<title>nvme-multipath: fix possible I/O hang when paths are updated</title>
<updated>2019-08-20T17:02:10+00:00</updated>
<author>
<name>Anton Eidelman</name>
<email>anton@lightbitslabs.com</email>
</author>
<published>2019-08-12T20:00:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/commit/?id=504db087aaccdb32af61539916409f7dca31ceb5'/>
<id>urn:sha1:504db087aaccdb32af61539916409f7dca31ceb5</id>
<content type='text'>
nvme_state_set_live() making a path available triggers requeue_work
in order to resubmit requests that ended up on requeue_list when no
paths were available.

This requeue_work may race with concurrent nvme_ns_head_make_request()
that do not observe the live path yet.
Such concurrent requests may by made by either:
- New IO submission.
- Requeue_work triggered by nvme_failover_req() or another ana_work.

A race may cause requeue_work capture the state of requeue_list before
more requests get onto the list. These requests will stay on the list
forever unless requeue_work is triggered again.

In order to prevent such race, nvme_state_set_live() should
synchronize_srcu(&amp;head-&gt;srcu) before triggering the requeue_work and
prevent nvme_ns_head_make_request referencing an old snapshot of the
path list.

Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Anton Eidelman &lt;anton@lightbitslabs.com&gt;
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
</entry>
<entry>
<title>Merge tag 'for-linus-2019-08-17' of git://git.kernel.dk/linux-block</title>
<updated>2019-08-18T02:39:54+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-08-18T02:39:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/commit/?id=8fde2832bd0bdc5a2b57330a9e9c3d2fa16bd1d8'/>
<id>urn:sha1:8fde2832bd0bdc5a2b57330a9e9c3d2fa16bd1d8</id>
<content type='text'>
Pull block fixes from Jens Axboe:
 "A collection of fixes that should go into this series. This contains:

   - Revert of the REQ_NOWAIT_INLINE and associated dio changes. There
     were still corner cases there, and even though I had a solution for
     it, it's too involved for this stage. (me)

   - Set of NVMe fixes (via Sagi)

   - io_uring fix for fixed buffers (Anthony)

   - io_uring defer issue fix (Jackie)

   - Regression fix for queue sync at exit time (zhengbin)

   - xen blk-back memory leak fix (Wenwen)"

* tag 'for-linus-2019-08-17' of git://git.kernel.dk/linux-block:
  io_uring: fix an issue when IOSQE_IO_LINK is inserted into defer list
  block: remove REQ_NOWAIT_INLINE
  io_uring: fix manual setup of iov_iter for fixed buffers
  xen/blkback: fix memory leaks
  blk-mq: move cancel of requeue_work to the front of blk_exit_queue
  nvme-pci: Fix async probe remove race
  nvme: fix controller removal race with scan work
  nvme-rdma: fix possible use-after-free in connect error flow
  nvme: fix a possible deadlock when passthru commands sent to a multipath device
  nvme-core: Fix extra device_put() call on error path
  nvmet-file: fix nvmet_file_flush() always returning an error
  nvmet-loop: Flush nvme_delete_wq when removing the port
  nvmet: Fix use-after-free bug when a port is removed
  nvme-multipath: revalidate nvme_ns_head gendisk in nvme_validate_ns
</content>
</entry>
<entry>
<title>nvme-pci: Allow PCI bus-level PM to be used if ASPM is disabled</title>
<updated>2019-08-12T08:47:55+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2019-08-08T21:58:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/commit/?id=4eaefe8c621c6195c91044396ed8060c179f7aae'/>
<id>urn:sha1:4eaefe8c621c6195c91044396ed8060c179f7aae</id>
<content type='text'>
One of the modifications made by commit d916b1be94b6 ("nvme-pci: use
host managed power state for suspend") was adding a pci_save_state()
call to nvme_suspend() so as to instruct the PCI bus type to leave
devices handled by the nvme driver in D0 during suspend-to-idle.
That was done with the assumption that ASPM would transition the
device's PCIe link into a low-power state when the device became
inactive.  However, if ASPM is disabled for the device, its PCIe
link will stay in L0 and in that case commit d916b1be94b6 is likely
to cause the energy used by the system while suspended to increase.

Namely, if the device in question works in accordance with the PCIe
specification, putting it into D3hot causes its PCIe link to go to
L1 or L2/L3 Ready, which is lower-power than L0.  Since the energy
used by the system while suspended depends on the state of its PCIe
link (as a general rule, the lower-power the state of the link, the
less energy the system will use), putting the device into D3hot
during suspend-to-idle should be more energy-efficient that leaving
it in D0 with disabled ASPM.

For this reason, avoid leaving NVMe devices with disabled ASPM in D0
during suspend-to-idle.  Instead, shut them down entirely and let
the PCI bus type put them into D3.

Fixes: d916b1be94b6 ("nvme-pci: use host managed power state for suspend")
Link: https://lore.kernel.org/linux-pm/2763495.NmdaWeg79L@kreacher/T/#t
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Keith Busch &lt;keith.busch@intel.com&gt;
</content>
</entry>
<entry>
<title>nvme-pci: Fix async probe remove race</title>
<updated>2019-08-01T01:03:36+00:00</updated>
<author>
<name>Keith Busch</name>
<email>kbusch@kernel.org</email>
</author>
<published>2019-07-29T22:34:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/commit/?id=bd46a90634302bfe791e93ad5496f98f165f7ae0'/>
<id>urn:sha1:bd46a90634302bfe791e93ad5496f98f165f7ae0</id>
<content type='text'>
Ensure the controller is not in the NEW state when nvme_probe() exits.
This will always allow a subsequent nvme_remove() to set the state to
DELETING, fixing a potential race between the initial asynchronous probe
and device removal.

Reported-by: Li Zhong &lt;lizhongfs@gmail.com&gt;
Reviewed-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Signed-off-by: Keith Busch &lt;kbusch@kernel.org&gt;
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
</content>
</entry>
<entry>
<title>nvme: fix controller removal race with scan work</title>
<updated>2019-08-01T01:01:56+00:00</updated>
<author>
<name>Sagi Grimberg</name>
<email>sagi@grimberg.me</email>
</author>
<published>2019-07-25T18:56:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/commit/?id=0157ec8dad3c8fc9bc9790f76e0831ffdaf2e7f0'/>
<id>urn:sha1:0157ec8dad3c8fc9bc9790f76e0831ffdaf2e7f0</id>
<content type='text'>
With multipath enabled, nvme_scan_work() can read from the device
(through nvme_mpath_add_disk()) and hang [1]. However, with fabrics,
once ctrl-&gt;state is set to NVME_CTRL_DELETING, the reads will hang
(see nvmf_check_ready()) and the mpath stack device make_request
will block if head-&gt;list is not empty. However, when the head-&gt;list
consistst of only DELETING/DEAD controllers, we should actually not
block, but rather fail immediately.

In addition, before we go ahead and remove the namespaces, make sure
to clear the current path and kick the requeue list so that the
request will fast fail upon requeuing.

[1]:
--
  INFO: task kworker/u4:3:166 blocked for more than 120 seconds.
        Not tainted 5.2.0-rc6-vmlocalyes-00005-g808c8c2dc0cf #316
  "echo 0 &gt; /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  kworker/u4:3    D    0   166      2 0x80004000
  Workqueue: nvme-wq nvme_scan_work
  Call Trace:
   __schedule+0x851/0x1400
   schedule+0x99/0x210
   io_schedule+0x21/0x70
   do_read_cache_page+0xa57/0x1330
   read_cache_page+0x4a/0x70
   read_dev_sector+0xbf/0x380
   amiga_partition+0xc4/0x1230
   check_partition+0x30f/0x630
   rescan_partitions+0x19a/0x980
   __blkdev_get+0x85a/0x12f0
   blkdev_get+0x2a5/0x790
   __device_add_disk+0xe25/0x1250
   device_add_disk+0x13/0x20
   nvme_mpath_set_live+0x172/0x2b0
   nvme_update_ns_ana_state+0x130/0x180
   nvme_set_ns_ana_state+0x9a/0xb0
   nvme_parse_ana_log+0x1c3/0x4a0
   nvme_mpath_add_disk+0x157/0x290
   nvme_validate_ns+0x1017/0x1bd0
   nvme_scan_work+0x44d/0x6a0
   process_one_work+0x7d7/0x1240
   worker_thread+0x8e/0xff0
   kthread+0x2c3/0x3b0
   ret_from_fork+0x35/0x40

   INFO: task kworker/u4:1:1034 blocked for more than 120 seconds.
        Not tainted 5.2.0-rc6-vmlocalyes-00005-g808c8c2dc0cf #316
  "echo 0 &gt; /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  kworker/u4:1    D    0  1034      2 0x80004000
  Workqueue: nvme-delete-wq nvme_delete_ctrl_work
  Call Trace:
   __schedule+0x851/0x1400
   schedule+0x99/0x210
   schedule_timeout+0x390/0x830
   wait_for_completion+0x1a7/0x310
   __flush_work+0x241/0x5d0
   flush_work+0x10/0x20
   nvme_remove_namespaces+0x85/0x3d0
   nvme_do_delete_ctrl+0xb4/0x1e0
   nvme_delete_ctrl_work+0x15/0x20
   process_one_work+0x7d7/0x1240
   worker_thread+0x8e/0xff0
   kthread+0x2c3/0x3b0
   ret_from_fork+0x35/0x40
--

Reported-by: Logan Gunthorpe &lt;logang@deltatee.com&gt;
Tested-by: Logan Gunthorpe &lt;logang@deltatee.com&gt;
Reviewed-by: Logan Gunthorpe &lt;logang@deltatee.com&gt;
Reviewed-by: Ming Lei &lt;ming.lei@redhat.com&gt;
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
</content>
</entry>
<entry>
<title>nvme-rdma: fix possible use-after-free in connect error flow</title>
<updated>2019-08-01T01:00:07+00:00</updated>
<author>
<name>Sagi Grimberg</name>
<email>sagi@grimberg.me</email>
</author>
<published>2019-07-26T17:29:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/commit/?id=d94211b8bad3787e0655a67284105f57db728cb1'/>
<id>urn:sha1:d94211b8bad3787e0655a67284105f57db728cb1</id>
<content type='text'>
When start_queue fails, we need to make sure to drain the
queue cq before freeing the rdma resources because we might
still race with the completion path. Have start_queue() error
path safely stop the queue.

--
[30371.808111] nvme nvme1: Failed reconnect attempt 11
[30371.808113] nvme nvme1: Reconnecting in 10 seconds...
[...]
[30382.069315] nvme nvme1: creating 4 I/O queues.
[30382.257058] nvme nvme1: Connect Invalid SQE Parameter, qid 4
[30382.257061] nvme nvme1: failed to connect queue: 4 ret=386
[30382.305001] BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
[30382.305022] IP: qedr_poll_cq+0x8a3/0x1170 [qedr]
[30382.305028] PGD 0 P4D 0
[30382.305037] Oops: 0000 [#1] SMP PTI
[...]
[30382.305153] Call Trace:
[30382.305166]  ? __switch_to_asm+0x34/0x70
[30382.305187]  __ib_process_cq+0x56/0xd0 [ib_core]
[30382.305201]  ib_poll_handler+0x26/0x70 [ib_core]
[30382.305213]  irq_poll_softirq+0x88/0x110
[30382.305223]  ? sort_range+0x20/0x20
[30382.305232]  __do_softirq+0xde/0x2c6
[30382.305241]  ? sort_range+0x20/0x20
[30382.305249]  run_ksoftirqd+0x1c/0x60
[30382.305258]  smpboot_thread_fn+0xef/0x160
[30382.305265]  kthread+0x113/0x130
[30382.305273]  ? kthread_create_worker_on_cpu+0x50/0x50
[30382.305281]  ret_from_fork+0x35/0x40
--

Reported-by: Nicolas Morey-Chaisemartin &lt;NMoreyChaisemartin@suse.com&gt;
Reviewed-by: Max Gurtovoy &lt;maxg@mellanox.com&gt;
Reviewed-by: Hannes Reinecke &lt;hare@suse.com&gt;
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
</content>
</entry>
<entry>
<title>nvme: fix a possible deadlock when passthru commands sent to a multipath device</title>
<updated>2019-08-01T00:59:01+00:00</updated>
<author>
<name>Sagi Grimberg</name>
<email>sagi@grimberg.me</email>
</author>
<published>2019-07-31T18:00:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/commit/?id=b9156daeb1601d69007b7e50efcf89d69d72ec1d'/>
<id>urn:sha1:b9156daeb1601d69007b7e50efcf89d69d72ec1d</id>
<content type='text'>
When the user issues a command with side effects, we will end up freezing
the namespace request queue when updating disk info (and the same for
the corresponding mpath disk node).

However, we are not freezing the mpath node request queue,
which means that mpath I/O can still come in and block on blk_queue_enter
(called from nvme_ns_head_make_request -&gt; direct_make_request).

This is a deadlock, because blk_queue_enter will block until the inner
namespace request queue is unfroze, but that process is blocked because
the namespace revalidation is trying to update the mpath disk info
and freeze its request queue (which will never complete because
of the I/O that is blocked on blk_queue_enter).

Fix this by freezing all the subsystem nsheads request queues before
executing the passthru command. Given that these commands are infrequent
we should not worry about this temporary I/O freeze to keep things sane.

Here is the matching hang traces:
--
[ 374.465002] INFO: task systemd-udevd:17994 blocked for more than 122 seconds.
[ 374.472975] Not tainted 5.2.0-rc3-mpdebug+ #42
[ 374.478522] "echo 0 &gt; /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 374.487274] systemd-udevd D 0 17994 1 0x00000000
[ 374.493407] Call Trace:
[ 374.496145] __schedule+0x2ef/0x620
[ 374.500047] schedule+0x38/0xa0
[ 374.503569] blk_queue_enter+0x139/0x220
[ 374.507959] ? remove_wait_queue+0x60/0x60
[ 374.512540] direct_make_request+0x60/0x130
[ 374.517219] nvme_ns_head_make_request+0x11d/0x420 [nvme_core]
[ 374.523740] ? generic_make_request_checks+0x307/0x6f0
[ 374.529484] generic_make_request+0x10d/0x2e0
[ 374.534356] submit_bio+0x75/0x140
[ 374.538163] ? guard_bio_eod+0x32/0xe0
[ 374.542361] submit_bh_wbc+0x171/0x1b0
[ 374.546553] block_read_full_page+0x1ed/0x330
[ 374.551426] ? check_disk_change+0x70/0x70
[ 374.556008] ? scan_shadow_nodes+0x30/0x30
[ 374.560588] blkdev_readpage+0x18/0x20
[ 374.564783] do_read_cache_page+0x301/0x860
[ 374.569463] ? blkdev_writepages+0x10/0x10
[ 374.574037] ? prep_new_page+0x88/0x130
[ 374.578329] ? get_page_from_freelist+0xa2f/0x1280
[ 374.583688] ? __alloc_pages_nodemask+0x179/0x320
[ 374.588947] read_cache_page+0x12/0x20
[ 374.593142] read_dev_sector+0x2d/0xd0
[ 374.597337] read_lba+0x104/0x1f0
[ 374.601046] find_valid_gpt+0xfa/0x720
[ 374.605243] ? string_nocheck+0x58/0x70
[ 374.609534] ? find_valid_gpt+0x720/0x720
[ 374.614016] efi_partition+0x89/0x430
[ 374.618113] ? string+0x48/0x60
[ 374.621632] ? snprintf+0x49/0x70
[ 374.625339] ? find_valid_gpt+0x720/0x720
[ 374.629828] check_partition+0x116/0x210
[ 374.634214] rescan_partitions+0xb6/0x360
[ 374.638699] __blkdev_reread_part+0x64/0x70
[ 374.643377] blkdev_reread_part+0x23/0x40
[ 374.647860] blkdev_ioctl+0x48c/0x990
[ 374.651956] block_ioctl+0x41/0x50
[ 374.655766] do_vfs_ioctl+0xa7/0x600
[ 374.659766] ? locks_lock_inode_wait+0xb1/0x150
[ 374.664832] ksys_ioctl+0x67/0x90
[ 374.668539] __x64_sys_ioctl+0x1a/0x20
[ 374.672732] do_syscall_64+0x5a/0x1c0
[ 374.676828] entry_SYSCALL_64_after_hwframe+0x44/0xa9

[ 374.738474] INFO: task nvmeadm:49141 blocked for more than 123 seconds.
[ 374.745871] Not tainted 5.2.0-rc3-mpdebug+ #42
[ 374.751419] "echo 0 &gt; /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 374.760170] nvmeadm D 0 49141 36333 0x00004080
[ 374.766301] Call Trace:
[ 374.769038] __schedule+0x2ef/0x620
[ 374.772939] schedule+0x38/0xa0
[ 374.776452] blk_mq_freeze_queue_wait+0x59/0x100
[ 374.781614] ? remove_wait_queue+0x60/0x60
[ 374.786192] blk_mq_freeze_queue+0x1a/0x20
[ 374.790773] nvme_update_disk_info.isra.57+0x5f/0x350 [nvme_core]
[ 374.797582] ? nvme_identify_ns.isra.50+0x71/0xc0 [nvme_core]
[ 374.804006] __nvme_revalidate_disk+0xe5/0x110 [nvme_core]
[ 374.810139] nvme_revalidate_disk+0xa6/0x120 [nvme_core]
[ 374.816078] ? nvme_submit_user_cmd+0x11e/0x320 [nvme_core]
[ 374.822299] nvme_user_cmd+0x264/0x370 [nvme_core]
[ 374.827661] nvme_dev_ioctl+0x112/0x1d0 [nvme_core]
[ 374.833114] do_vfs_ioctl+0xa7/0x600
[ 374.837117] ? __audit_syscall_entry+0xdd/0x130
[ 374.842184] ksys_ioctl+0x67/0x90
[ 374.845891] __x64_sys_ioctl+0x1a/0x20
[ 374.850082] do_syscall_64+0x5a/0x1c0
[ 374.854178] entry_SYSCALL_64_after_hwframe+0x44/0xa9
--

Reported-by: James Puthukattukaran &lt;james.puthukattukaran@oracle.com&gt;
Tested-by: James Puthukattukaran &lt;james.puthukattukaran@oracle.com&gt;
Reviewed-by: Keith Busch &lt;kbusch@kernel.org&gt;
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
</content>
</entry>
<entry>
<title>nvme-core: Fix extra device_put() call on error path</title>
<updated>2019-08-01T00:57:24+00:00</updated>
<author>
<name>Logan Gunthorpe</name>
<email>logang@deltatee.com</email>
</author>
<published>2019-07-31T23:35:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.raptorcs.com/git/blackbird-op-linux/commit/?id=8c36e66fb407ce076535a7db98ab9f6d720b866a'/>
<id>urn:sha1:8c36e66fb407ce076535a7db98ab9f6d720b866a</id>
<content type='text'>
In the error path for nvme_init_subsystem(), nvme_put_subsystem()
will call device_put(), but it will get called again after the
mutex_unlock().

The device_put() only needs to be called if device_add() fails.

This bug caused a KASAN use-after-free error when adding and
removing subsytems in a loop:

  BUG: KASAN: use-after-free in device_del+0x8d9/0x9a0
  Read of size 8 at addr ffff8883cdaf7120 by task multipathd/329

  CPU: 0 PID: 329 Comm: multipathd Not tainted 5.2.0-rc6-vmlocalyes-00019-g70a2b39005fd-dirty #314
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
  Call Trace:
   dump_stack+0x7b/0xb5
   print_address_description+0x6f/0x280
   ? device_del+0x8d9/0x9a0
   __kasan_report+0x148/0x199
   ? device_del+0x8d9/0x9a0
   ? class_release+0x100/0x130
   ? device_del+0x8d9/0x9a0
   kasan_report+0x12/0x20
   __asan_report_load8_noabort+0x14/0x20
   device_del+0x8d9/0x9a0
   ? device_platform_notify+0x70/0x70
   nvme_destroy_subsystem+0xf9/0x150
   nvme_free_ctrl+0x280/0x3a0
   device_release+0x72/0x1d0
   kobject_put+0x144/0x410
   put_device+0x13/0x20
   nvme_free_ns+0xc4/0x100
   nvme_release+0xb3/0xe0
   __blkdev_put+0x549/0x6e0
   ? kasan_check_write+0x14/0x20
   ? bd_set_size+0xb0/0xb0
   ? kasan_check_write+0x14/0x20
   ? mutex_lock+0x8f/0xe0
   ? __mutex_lock_slowpath+0x20/0x20
   ? locks_remove_file+0x239/0x370
   blkdev_put+0x72/0x2c0
   blkdev_close+0x8d/0xd0
   __fput+0x256/0x770
   ? _raw_read_lock_irq+0x40/0x40
   ____fput+0xe/0x10
   task_work_run+0x10c/0x180
   ? filp_close+0xf7/0x140
   exit_to_usermode_loop+0x151/0x170
   do_syscall_64+0x240/0x2e0
   ? prepare_exit_to_usermode+0xd5/0x190
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x7f5a79af05d7
  Code: 00 00 0f 05 48 3d 00 f0 ff ff 77 3f c3 66 0f 1f 44 00 00 53 89 fb 48 83 ec 10 e8 c4 fb ff ff 89 df 89 c2 b8 03 00 00 00 0f 05 &lt;48&gt; 3d 00 f0 ff ff 77 2b 89 d7 89 44 24 0c e8 06 fc ff ff 8b 44 24
  RSP: 002b:00007f5a7799c810 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
  RAX: 0000000000000000 RBX: 0000000000000008 RCX: 00007f5a79af05d7
  RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000008
  RBP: 00007f5a58000f98 R08: 0000000000000002 R09: 00007f5a7935ee80
  R10: 0000000000000000 R11: 0000000000000293 R12: 000055e432447240
  R13: 0000000000000000 R14: 0000000000000001 R15: 000055e4324a9cf0

  Allocated by task 1236:
   save_stack+0x21/0x80
   __kasan_kmalloc.constprop.6+0xab/0xe0
   kasan_kmalloc+0x9/0x10
   kmem_cache_alloc_trace+0x102/0x210
   nvme_init_identify+0x13c3/0x3820
   nvme_loop_configure_admin_queue+0x4fa/0x5e0
   nvme_loop_create_ctrl+0x469/0xf40
   nvmf_dev_write+0x19a3/0x21ab
   __vfs_write+0x66/0x120
   vfs_write+0x154/0x490
   ksys_write+0x104/0x240
   __x64_sys_write+0x73/0xb0
   do_syscall_64+0xa5/0x2e0
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

  Freed by task 329:
   save_stack+0x21/0x80
   __kasan_slab_free+0x129/0x190
   kasan_slab_free+0xe/0x10
   kfree+0xa7/0x200
   nvme_release_subsystem+0x49/0x60
   device_release+0x72/0x1d0
   kobject_put+0x144/0x410
   put_device+0x13/0x20
   klist_class_dev_put+0x31/0x40
   klist_put+0x8f/0xf0
   klist_del+0xe/0x10
   device_del+0x3a7/0x9a0
   nvme_destroy_subsystem+0xf9/0x150
   nvme_free_ctrl+0x280/0x3a0
   device_release+0x72/0x1d0
   kobject_put+0x144/0x410
   put_device+0x13/0x20
   nvme_free_ns+0xc4/0x100
   nvme_release+0xb3/0xe0
   __blkdev_put+0x549/0x6e0
   blkdev_put+0x72/0x2c0
   blkdev_close+0x8d/0xd0
   __fput+0x256/0x770
   ____fput+0xe/0x10
   task_work_run+0x10c/0x180
   exit_to_usermode_loop+0x151/0x170
   do_syscall_64+0x240/0x2e0
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 32fd90c40768 ("nvme: change locking for the per-subsystem controller list")
Signed-off-by: Logan Gunthorpe &lt;logang@deltatee.com&gt;
Reviewed-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
Reviewed-by : Chaitanya Kulkarni &lt;chaitanya.kulkarni@wdc.com&gt;
Signed-off-by: Sagi Grimberg &lt;sagi@grimberg.me&gt;
</content>
</entry>
</feed>
