Factor out the code to try to get q_usage_counter without blocking into
a separate helper.  Both to improve code readability and to prepare for
splitting bio_queue_enter from blk_queue_enter.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20210929071241.934472-3-hch@lst.deTested-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Ensure all bios check the current values of the queue under freeze
protection, i.e. to make sure the zero capacity set by del_gendisk
is actually seen before dispatching to the driver.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210929071241.934472-2-hch@lst.deTested-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Pull NVMe fixes from Christoph:

"nvme fixes for Linux 5.15:

 - fix the abort command id (Keith Busch)
 - nvme: fix per-namespace chardev deletion (Adam Manzanares)"

* tag 'nvme-5.15-2021-10-14' of git://git.infradead.org/nvme:
  nvme: fix per-namespace chardev deletion
  nvme-pci: Fix abort command id

Decrease reference count of chardevice during char device deletion in
order to fix a memory leak.  Add a release callabck for the device
associated chardev and move ida_simple_remove into the release function.

Fixes: 2637baed ("nvme: introduce generic per-namespace chardev")
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Suggested-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Adam Manzanares <a.manzanares@samsung.com>
Reviewed-by: Javier González <javier@javigon.com>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

These variables are printed on the error path if match_int() fails so
they have to be initialized.

Fixes: 2958a995 ("block/rnbd-clt: Support polling mode for IO latency optimization")
Fixes: 1eb54f8f ("block/rnbd: client: sysfs interface functions")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Gioh Kim <gi-oh.kim@ionos.com>
Link: https://lore.kernel.org/r/20211012084443.GA31472@kiliSigned-off-by: Jens Axboe <axboe@kernel.dk>

The request tag is no longer the only component of the command id.

Fixes: e7006de6 ("nvme: code command_id with a genctr for use-after-free validation")
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>

While debugging an issue we've found that $DEBUGFS/block/$disk/state
doesn't decode QUEUE_FLAG_HCTX_ACTIVE but only displays its numerical
value.

Add QUEUE_FLAG(HCTX_ACTIVE) to the blk_queue_flag_name array so it'll get
decoded properly.
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/4351076388918075bd80ef07756f9d2ce63be12c.1633332053.git.johannes.thumshirn@wdc.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

syzbot is reporting use-after-free read at bdev_free_inode() [1], for
kfree() from __alloc_disk_node() is called before bdev_free_inode()
(which is called after RCU grace period) reads bdev->bd_disk and calls
kfree(bdev->bd_disk).

Fix use-after-free read followed by double kfree() problem
by making sure that bdev->bd_disk is NULL when calling iput().

Link: https://syzkaller.appspot.com/bug?extid=8281086e8a6fbfbd952a [1]
Reported-by: syzbot <syzbot+8281086e8a6fbfbd952a@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/e6dd13c5-8db0-4392-6e78-a42ee5d2a1c4@i-love.sakura.ne.jpSigned-off-by: Jens Axboe <axboe@kernel.dk>

commit fad7cd33 ("nbd: add the check to prevent overflow in
__nbd_ioctl()") raised an issue from the fallback helpers added in
commit f0907827 ("compiler.h: enable builtin overflow checkers and
add fallback code")

ERROR: modpost: "__divdi3" [drivers/block/nbd.ko] undefined!

As Stephen Rothwell notes:
  The added check_mul_overflow() call is being passed 64 bit values.
  COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW is not set for this build (see
  include/linux/overflow.h).

Specifically, the helpers for checking whether the results of a
multiplication overflowed (__unsigned_mul_overflow,
__signed_add_overflow) use the division operator when
!COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW.  This is problematic for 64b
operands on 32b hosts.

This was fixed upstream by
commit 76ae8474 ("Documentation: raise minimum supported version of
GCC to 5.1")
which is not suitable to be backported to stable.

Further, __builtin_mul_overflow() would emit a libcall to a
compiler-rt-only symbol when compiling with clang < 14 for 32b targets.

ld.lld: error: undefined symbol: __mulodi4

In order to keep stable buildable with GCC 4.9 and clang < 14, modify
struct nbd_config to instead track the number of bits of the block size;
reconstructing the block size using runtime checked shifts that are not
problematic for those compilers and in a ways that can be backported to
stable.

In nbd_set_size, we do validate that the value of blksize must be a
power of two (POT) and is in the range of [512, PAGE_SIZE] (both
inclusive).

This does modify the debugfs interface.

Cc: stable@vger.kernel.org
Cc: Arnd Bergmann <arnd@kernel.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Link: https://github.com/ClangBuiltLinux/linux/issues/1438
Link: https://lore.kernel.org/all/20210909182525.372ee687@canb.auug.org.au/
Link: https://lore.kernel.org/stable/CAHk-=whiQBofgis_rkniz8GBP9wZtSZdcDEffgSLO62BUGV3gg@mail.gmail.com/Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Suggested-by: Kees Cook <keescook@chromium.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Suggested-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20210920232533.4092046-1-ndesaulniers@google.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

This reverts commit 2d52c58b.

We have had several folks complain that this causes hangs for them, which
is especially problematic as the commit has also hit stable already.

As no resolution seems to be forthcoming right now, revert the patch.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=214503
Fixes: 2d52c58b ("block, bfq: honor already-setup queue merges")
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Some apple controllers use the command id as an index to implementation
specific data structures and will fail if the value is out of bounds.
The nvme driver's recently introduced command sequence number breaks
this controller.

Provide a quirk so these spec incompliant controllers can function as
before. The driver will not have the ability to detect bad completions
when this quirk is used, but we weren't previously checking this anyway.

The quirk bit was selected so that it can readily apply to stable.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=214509
Cc: Sven Peter <sven@svenpeter.dev>
Reported-by: Orlando Chamberlain <redecorating@protonmail.com>
Reported-by: Aditya Garg <gargaditya08@live.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Sven Peter <sven@svenpeter.dev>
Link: https://lore.kernel.org/r/20210927154306.387437-1-kbusch@kernel.orgSigned-off-by: Jens Axboe <axboe@kernel.dk>

When running ->fallocate(), blkdev_fallocate() should hold
mapping->invalidate_lock to prevent page cache from being accessed,
otherwise stale data may be read in page cache.

Without this patch, blktests block/009 fails sometimes. With this patch,
block/009 can pass always.

Also as Jan pointed out, no pages can be created in the discarded area
while you are holding the invalidate_lock, so remove the 2nd
truncate_bdev_range().

Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210923023751.1441091-1-ming.lei@redhat.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

There is an use-after-free problem triggered by following process:

      P1(sda)				P2(sdb)
			echo 0 > /sys/block/sdb/trace/enable
			  blk_trace_remove_queue
			    synchronize_rcu
			    blk_trace_free
			      relay_close
rcu_read_lock
__blk_add_trace
  trace_note_tsk
  (Iterate running_trace_list)
			        relay_close_buf
				  relay_destroy_buf
				    kfree(buf)
    trace_note(sdb's bt)
      relay_reserve
        buf->offset <- nullptr deference (use-after-free) !!!
rcu_read_unlock

[  502.714379] BUG: kernel NULL pointer dereference, address:
0000000000000010
[  502.715260] #PF: supervisor read access in kernel mode
[  502.715903] #PF: error_code(0x0000) - not-present page
[  502.716546] PGD 103984067 P4D 103984067 PUD 17592b067 PMD 0
[  502.717252] Oops: 0000 [#1] SMP
[  502.720308] RIP: 0010:trace_note.isra.0+0x86/0x360
[  502.732872] Call Trace:
[  502.733193]  __blk_add_trace.cold+0x137/0x1a3
[  502.733734]  blk_add_trace_rq+0x7b/0xd0
[  502.734207]  blk_add_trace_rq_issue+0x54/0xa0
[  502.734755]  blk_mq_start_request+0xde/0x1b0
[  502.735287]  scsi_queue_rq+0x528/0x1140
...
[  502.742704]  sg_new_write.isra.0+0x16e/0x3e0
[  502.747501]  sg_ioctl+0x466/0x1100

Reproduce method:
  ioctl(/dev/sda, BLKTRACESETUP, blk_user_trace_setup[buf_size=127])
  ioctl(/dev/sda, BLKTRACESTART)
  ioctl(/dev/sdb, BLKTRACESETUP, blk_user_trace_setup[buf_size=127])
  ioctl(/dev/sdb, BLKTRACESTART)

  echo 0 > /sys/block/sdb/trace/enable &
  // Add delay(mdelay/msleep) before kernel enters blk_trace_free()

  ioctl$SG_IO(/dev/sda, SG_IO, ...)
  // Enters trace_note_tsk() after blk_trace_free() returned
  // Use mdelay in rcu region rather than msleep(which may schedule out)

Remove blk_trace from running_list before calling blk_trace_free() by
sysfs if blk_trace is at Blktrace_running state.

Fixes: c71a8961 ("blktrace: add ftrace plugin")
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Link: https://lore.kernel.org/r/20210923134921.109194-1-chengzhihao1@huawei.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

rq_qos framework is only applied on request based driver, so:

1) rq_qos_done_bio() needn't to be called for bio based driver

2) rq_qos_done_bio() needn't to be called for bio which isn't tracked,
such as bios ended from error handling code.

Especially in bio_endio():

1) request queue is referred via bio->bi_bdev->bd_disk->queue, which
may be gone since request queue refcount may not be held in above two
cases

2) q->rq_qos may be freed in blk_cleanup_queue() when calling into
__rq_qos_done_bio()

Fix the potential kernel panic by not calling rq_qos_ops->done_bio if
the bio isn't tracked. This way is safe because both ioc_rqos_done_bio()
and blkcg_iolatency_done_bio() are nop if the bio isn't tracked.
Reported-by: Yu Kuai <yukuai3@huawei.com>
Cc: tj@kernel.org
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20210924110704.1541818-1-ming.lei@redhat.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pull NVMe fixes from Christoph:

"nvme fixes for Linux 5.15:

 - keep ctrl->namespaces ordered (me)
 - fix incorrect h2cdata pdu offset accounting in nvme-tcp
   (Sagi Grimberg)
 - handled updated hw_queues in nvme-fc more carefully (Daniel Wagner,
   James Smart)"

* tag 'nvme-5.15-2021-09-24' of git://git.infradead.org/nvme:
  nvme: keep ctrl->namespaces ordered
  nvme-tcp: fix incorrect h2cdata pdu offset accounting
  nvme-fc: remove freeze/unfreeze around update_nr_hw_queues
  nvme-fc: avoid race between time out and tear down
  nvme-fc: update hardware queues before using them

Pull MD fix from Song.

* 'md-fixes' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md:
  md: fix a lock order reversal in md_alloc

Commit b0140891 ("md: Fix race when creating a new md device.")
not only moved assigning mddev->gendisk before calling add_disk, which
fixes the races described in the commit log, but also added a
mddev->open_mutex critical section over add_disk and creation of the
md kobj.  Adding a kobject after add_disk is racy vs deleting the gendisk
right after adding it, but md already prevents against that by holding
a mddev->active reference.

On the other hand taking this lock added a lock order reversal with what
is not disk->open_mutex (used to be bdev->bd_mutex when the commit was
added) for partition devices, which need that lock for the internal open
for the partition scan, and a recent commit also takes it for
non-partitioned devices, leading to further lockdep splatter.

Fixes: b0140891 ("md: Fix race when creating a new md device.")
Fixes: d6263387 ("block: support delayed holder registration")
Reported-by: syzbot+fadc0aaf497e6a493b9f@syzkaller.appspotmail.com
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: syzbot+fadc0aaf497e6a493b9f@syzkaller.appspotmail.com
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Song Liu <songliubraving@fb.com>

Various places in the nvme code that rely on ctrl->namespace to be
ordered.  Ensure that the namespae is inserted into the list at the
right position from the start instead of sorting it after the fact.

Fixes: 540c801c ("NVMe: Implement namespace list scanning")
Reported-by: Anton Eidelman <anton.eidelman@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>

When the controller sends us multiple r2t PDUs in a single
request we need to account for it correctly as our send/recv
context run concurrently (i.e. we get a new r2t with r2t_offset
before we updated our iterator and req->data_sent marker). This
can cause wrong offsets to be sent to the controller.

To fix that, we will first know that this may happen only in
the send sequence of the last page, hence we will take
the r2t_offset to the h2c PDU data_offset, and in
nvme_tcp_try_send_data loop, we make sure to increment
the request markers also when we completed a PDU but
we are expecting more r2t PDUs as we still did not send
the entire data of the request.

Fixes: 825619b0 ("nvme-tcp: fix possible use-after-completion")
Reported-by: Nowak, Lukasz <Lukasz.Nowak@Dell.com>
Tested-by: Nowak, Lukasz <Lukasz.Nowak@Dell.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Remove the freeze/unfreeze around changes to the number of hardware
queues. Study and retest has indicated there are no ios that can be
active at this point so there is nothing to freeze.

nvme-fc is draining the queues in the shutdown and error recovery path
in __nvme_fc_abort_outstanding_ios.

This patch primarily reverts 88e837ed "nvme-fc: wait for queues to
freeze before calling update_hr_hw_queues". It's not an exact revert as
it leaves the adjusting of hw queues only if the count changes.
Signed-off-by: James Smart <jsmart2021@gmail.com>
[dwagner: added explanation why no IO is pending]
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

To avoid race between time out and tear down, in tear down process,
first we quiesce the queue, and then delete the timer and cancel
the time out work for the queue.

This patch merges the admin and io sync ops into the queue teardown logic
as shown in the RDMA patch 3017013d "nvme-rdma: avoid race between time
out and tear down". There is no teardown_lock in nvme-fc.
Signed-off-by: James Smart <jsmart2021@gmail.com>
Tested-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

In case the number of hardware queues changes, we need to update the
tagset and the mapping of ctx to hctx first.

If we try to create and connect the I/O queues first, this operation
will fail (target will reject the connect call due to the wrong number
of queues) and hence we bail out of the recreate function. Then we
will to try the very same operation again, thus we don't make any
progress.
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

KASAN reports a use-after-free report when doing fuzz test:

[693354.104835] ==================================================================
[693354.105094] BUG: KASAN: use-after-free in bfq_io_set_weight_legacy+0xd3/0x160
[693354.105336] Read of size 4 at addr ffff888be0a35664 by task sh/1453338

[693354.105607] CPU: 41 PID: 1453338 Comm: sh Kdump: loaded Not tainted 4.18.0-147
[693354.105610] Hardware name: Huawei 2288H V5/BC11SPSCB0, BIOS 0.81 07/02/2018
[693354.105612] Call Trace:
[693354.105621]  dump_stack+0xf1/0x19b
[693354.105626]  ? show_regs_print_info+0x5/0x5
[693354.105634]  ? printk+0x9c/0xc3
[693354.105638]  ? cpumask_weight+0x1f/0x1f
[693354.105648]  print_address_description+0x70/0x360
[693354.105654]  kasan_report+0x1b2/0x330
[693354.105659]  ? bfq_io_set_weight_legacy+0xd3/0x160
[693354.105665]  ? bfq_io_set_weight_legacy+0xd3/0x160
[693354.105670]  bfq_io_set_weight_legacy+0xd3/0x160
[693354.105675]  ? bfq_cpd_init+0x20/0x20
[693354.105683]  cgroup_file_write+0x3aa/0x510
[693354.105693]  ? ___slab_alloc+0x507/0x540
[693354.105698]  ? cgroup_file_poll+0x60/0x60
[693354.105702]  ? 0xffffffff89600000
[693354.105708]  ? usercopy_abort+0x90/0x90
[693354.105716]  ? mutex_lock+0xef/0x180
[693354.105726]  kernfs_fop_write+0x1ab/0x280
[693354.105732]  ? cgroup_file_poll+0x60/0x60
[693354.105738]  vfs_write+0xe7/0x230
[693354.105744]  ksys_write+0xb0/0x140
[693354.105749]  ? __ia32_sys_read+0x50/0x50
[693354.105760]  do_syscall_64+0x112/0x370
[693354.105766]  ? syscall_return_slowpath+0x260/0x260
[693354.105772]  ? do_page_fault+0x9b/0x270
[693354.105779]  ? prepare_exit_to_usermode+0xf9/0x1a0
[693354.105784]  ? enter_from_user_mode+0x30/0x30
[693354.105793]  entry_SYSCALL_64_after_hwframe+0x65/0xca

[693354.105875] Allocated by task 1453337:
[693354.106001]  kasan_kmalloc+0xa0/0xd0
[693354.106006]  kmem_cache_alloc_node_trace+0x108/0x220
[693354.106010]  bfq_pd_alloc+0x96/0x120
[693354.106015]  blkcg_activate_policy+0x1b7/0x2b0
[693354.106020]  bfq_create_group_hierarchy+0x1e/0x80
[693354.106026]  bfq_init_queue+0x678/0x8c0
[693354.106031]  blk_mq_init_sched+0x1f8/0x460
[693354.106037]  elevator_switch_mq+0xe1/0x240
[693354.106041]  elevator_switch+0x25/0x40
[693354.106045]  elv_iosched_store+0x1a1/0x230
[693354.106049]  queue_attr_store+0x78/0xb0
[693354.106053]  kernfs_fop_write+0x1ab/0x280
[693354.106056]  vfs_write+0xe7/0x230
[693354.106060]  ksys_write+0xb0/0x140
[693354.106064]  do_syscall_64+0x112/0x370
[693354.106069]  entry_SYSCALL_64_after_hwframe+0x65/0xca

[693354.106114] Freed by task 1453336:
[693354.106225]  __kasan_slab_free+0x130/0x180
[693354.106229]  kfree+0x90/0x1b0
[693354.106233]  blkcg_deactivate_policy+0x12c/0x220
[693354.106238]  bfq_exit_queue+0xf5/0x110
[693354.106241]  blk_mq_exit_sched+0x104/0x130
[693354.106245]  __elevator_exit+0x45/0x60
[693354.106249]  elevator_switch_mq+0xd6/0x240
[693354.106253]  elevator_switch+0x25/0x40
[693354.106257]  elv_iosched_store+0x1a1/0x230
[693354.106261]  queue_attr_store+0x78/0xb0
[693354.106264]  kernfs_fop_write+0x1ab/0x280
[693354.106268]  vfs_write+0xe7/0x230
[693354.106271]  ksys_write+0xb0/0x140
[693354.106275]  do_syscall_64+0x112/0x370
[693354.106280]  entry_SYSCALL_64_after_hwframe+0x65/0xca

[693354.106329] The buggy address belongs to the object at ffff888be0a35580
                 which belongs to the cache kmalloc-1k of size 1024
[693354.106736] The buggy address is located 228 bytes inside of
                 1024-byte region [ffff888be0a35580, ffff888be0a35980)
[693354.107114] The buggy address belongs to the page:
[693354.107273] page:ffffea002f828c00 count:1 mapcount:0 mapping:ffff888107c17080 index:0x0 compound_mapcount: 0
[693354.107606] flags: 0x17ffffc0008100(slab|head)
[693354.107760] raw: 0017ffffc0008100 ffffea002fcbc808 ffffea0030bd3a08 ffff888107c17080
[693354.108020] raw: 0000000000000000 00000000001c001c 00000001ffffffff 0000000000000000
[693354.108278] page dumped because: kasan: bad access detected

[693354.108511] Memory state around the buggy address:
[693354.108671]  ffff888be0a35500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[693354.116396]  ffff888be0a35580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[693354.124473] >ffff888be0a35600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[693354.132421]                                                        ^
[693354.140284]  ffff888be0a35680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[693354.147912]  ffff888be0a35700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[693354.155281] ==================================================================

blkgs are protected by both queue and blkcg locks and holding
either should stabilize them. However, the path of destroying
blkg policy data is only protected by queue lock in
blkcg_activate_policy()/blkcg_deactivate_policy(). Other tasks
can get the blkg policy data before the blkg policy data is
destroyed, and use it after destroyed, which will result in a
use-after-free.

CPU0                             CPU1
blkcg_deactivate_policy
  spin_lock_irq(&q->queue_lock)
                                 bfq_io_set_weight_legacy
                                   spin_lock_irq(&blkcg->lock)
                                   blkg_to_bfqg(blkg)
                                     pd_to_bfqg(blkg->pd[pol->plid])
                                     ^^^^^^blkg->pd[pol->plid] != NULL
                                           bfqg != NULL
  pol->pd_free_fn(blkg->pd[pol->plid])
    pd_to_bfqg(blkg->pd[pol->plid])
    bfqg_put(bfqg)
      kfree(bfqg)
  blkg->pd[pol->plid] = NULL
  spin_unlock_irq(q->queue_lock);
                                   bfq_group_set_weight(bfqg, val, 0)
                                     bfqg->entity.new_weight
                                     ^^^^^^trigger uaf here
                                   spin_unlock_irq(&blkcg->lock);

Fix by grabbing the matching blkcg lock before trying to
destroy blkg policy data.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Li Jinlin <lijinlin3@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20210914042605.3260596-1-lijinlin3@huawei.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

BUG: memory leak
unreferenced object 0xffff888129acdb80 (size 96):
  comm "syz-executor.1", pid 12661, jiffies 4294962682 (age 15.220s)
  hex dump (first 32 bytes):
    20 47 c9 85 ff ff ff ff 20 d4 8e 29 81 88 ff ff   G...... ..)....
    01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff82264ec8>] kmalloc include/linux/slab.h:591 [inline]
    [<ffffffff82264ec8>] kzalloc include/linux/slab.h:721 [inline]
    [<ffffffff82264ec8>] blk_iolatency_init+0x28/0x190 block/blk-iolatency.c:724
    [<ffffffff8225b8c4>] blkcg_init_queue+0xb4/0x1c0 block/blk-cgroup.c:1185
    [<ffffffff822253da>] blk_alloc_queue+0x22a/0x2e0 block/blk-core.c:566
    [<ffffffff8223b175>] blk_mq_init_queue_data block/blk-mq.c:3100 [inline]
    [<ffffffff8223b175>] __blk_mq_alloc_disk+0x25/0xd0 block/blk-mq.c:3124
    [<ffffffff826a9303>] loop_add+0x1c3/0x360 drivers/block/loop.c:2344
    [<ffffffff826a966e>] loop_control_get_free drivers/block/loop.c:2501 [inline]
    [<ffffffff826a966e>] loop_control_ioctl+0x17e/0x2e0 drivers/block/loop.c:2516
    [<ffffffff81597eec>] vfs_ioctl fs/ioctl.c:51 [inline]
    [<ffffffff81597eec>] __do_sys_ioctl fs/ioctl.c:874 [inline]
    [<ffffffff81597eec>] __se_sys_ioctl fs/ioctl.c:860 [inline]
    [<ffffffff81597eec>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:860
    [<ffffffff843fa745>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    [<ffffffff843fa745>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
    [<ffffffff84600068>] entry_SYSCALL_64_after_hwframe+0x44/0xae

Once blk_throtl_init() queue init failed, blkcg_iolatency_exit() will
not be invoked for cleanup. That leads a memory leak. Swap the
blk_throtl_init() and blk_iolatency_init() calls can solve this.

Reported-by: syzbot+01321b15cc98e6bf96d6@syzkaller.appspotmail.com
Fixes: 19688d7f (block/blk-cgroup: Swap the blk_throtl_init() and blk_iolatency_init() calls)
Signed-off-by: Yanfei Xu <yanfei.xu@windriver.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20210915072426.4022924-1-yanfei.xu@windriver.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Pull NVMe fixes from Christoph:

"nvme fixes for Linux 5.15

 - fix ANA state updates when a namespace is not present (Anton Eidelman)
 - nvmet: fix a width vs precision bug in nvmet_subsys_attr_serial_show
   (Dan Carpenter)
 - avoid race in shutdown namespace removal (Daniel Wagner)
 - fix io_work priority inversion in nvme-tcp (Keith Busch)
 - destroy cm id before destroy qp to avoid use after free (Ruozhu Li)"

* tag 'nvme-5.15-2021-09-15' of git://git.infradead.org/nvme:
  nvme-tcp: fix io_work priority inversion
  nvme-rdma: destroy cm id before destroy qp to avoid use after free
  nvme-multipath: fix ANA state updates when a namespace is not present
  nvme: avoid race in shutdown namespace removal
  nvmet: fix a width vs precision bug in nvmet_subsys_attr_serial_show()

There is no need to explicitly unregister the integrity profile when
deleting the gendisk.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Link: https://lore.kernel.org/r/20210914070657.87677-4-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

When the integrity profile is unregistered there can still be integrity
reads queued up which could see a NULL verify_fn as shown by the race
window below:

CPU0                                    CPU1
  process_one_work                      nvme_validate_ns
    bio_integrity_verify_fn                nvme_update_ns_info
	                                     nvme_update_disk_info
	                                       blk_integrity_unregister
                                               ---set queue->integrity as 0
	bio_integrity_process
	--access bi->profile->verify_fn(bi is a pointer of queue->integity)

Before calling blk_integrity_unregister in nvme_update_disk_info, we must
make sure that there is no work item in the kintegrityd_wq. Just call
blk_flush_integrity to flush the work queue so the bug can be resolved.
Signed-off-by: Lihong Kou <koulihong@huawei.com>
[hch: split up and shortened the changelog]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Link: https://lore.kernel.org/r/20210914070657.87677-3-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

While clearing the profile itself is harmless, we really should not clear
the stable writes flag if it wasn't set due to a registered integrity
profile.
Reported-by: Lihong Kou <koulihong@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Link: https://lore.kernel.org/r/20210914070657.87677-2-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

Dispatching requests inline with the .queue_rq() call may block while
holding the send_mutex. If the tcp io_work also happens to schedule, it
may see the req_list is non-empty, leaving "pending" true and remaining
in TASK_RUNNING. Since io_work is of higher scheduling priority, the
.queue_rq task may not get a chance to run, blocking forward progress
and leading to io timeouts.

Instead of checking for pending requests within io_work, let the queueing
restart io_work outside the send_mutex lock if there is more work to be
done.

Fixes: a0fdd141 ("nvme-tcp: rerun io_work if req_list is not empty")
Reported-by: Samuel Jones <sjones@kalrayinc.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

We should always destroy cm_id before destroy qp to avoid to get cma
event after qp was destroyed, which may lead to use after free.
In RDMA connection establishment error flow, don't destroy qp in cm
event handler.Just report cm_error to upper level, qp will be destroy
in nvme_rdma_alloc_queue() after destroy cm id.
Signed-off-by: Ruozhu Li <liruozhu@huawei.com>
Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

nvme_update_ana_state() has a deficiency that results in a failure to
properly update the ana state for a namespace in the following case:

  NSIDs in ctrl->namespaces:	1, 3,    4
  NSIDs in desc->nsids:		1, 2, 3, 4

Loop iteration 0:
    ns index = 0, n = 0, ns->head->ns_id = 1, nsid = 1, MATCH.
Loop iteration 1:
    ns index = 1, n = 1, ns->head->ns_id = 3, nsid = 2, NO MATCH.
Loop iteration 2:
    ns index = 2, n = 2, ns->head->ns_id = 4, nsid = 4, MATCH.

Where the update to the ANA state of NSID 3 is missed.  To fix this
increment n and retry the update with the same ns when ns->head->ns_id is
higher than nsid,
Signed-off-by: Anton Eidelman <anton@lightbitslabs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>

When we remove the siblings entry, we update ns->head->list, hence we
can't separate the removal and test for being empty. They have to be
in the same critical section to avoid a race.

To avoid breaking the refcounting imbalance again, add a list empty
check to nvme_find_ns_head.

Fixes: 5396fdac ("nvme: fix refcounting imbalance when all paths are down")
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

This was intended to limit the number of characters printed from
"subsys->serial" to NVMET_SN_MAX_SIZE.  But accidentally the width
specifier was used instead of the precision specifier so it only
affects the alignment and not the number of characters printed.

Fixes: f0406481 ("nvmet: fixup buffer overrun in nvmet_subsys_attr_serial()")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

blk-mq can't run allocating driver tag and updating ->rqs[tag]
atomically, meantime blk-mq doesn't clear ->rqs[tag] after the driver
tag is released.

So there is chance to iterating over one stale request just after the
tag is allocated and before updating ->rqs[tag].

scsi_host_busy_iter() calls scsi_host_check_in_flight() to count scsi
in-flight requests after scsi host is blocked, so no new scsi command can
be marked as SCMD_STATE_INFLIGHT. However, driver tag allocation still can
be run by blk-mq core. One request is marked as SCMD_STATE_INFLIGHT,
but this request may have been kept in another slot of ->rqs[], meantime
the slot can be allocated out but ->rqs[] isn't updated yet. Then this
in-flight request is counted twice as SCMD_STATE_INFLIGHT. This way causes
trouble in handling scsi error.

Fixes the issue by not iterating over stale request.

Cc: linux-scsi@vger.kernel.org
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Reported-by: luojiaxing <luojiaxing@huawei.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210906065003.439019-1-ming.lei@redhat.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

Merge tag 'perf-tools-for-v5.15-2021-09-11' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

Pull more perf tools updates from Arnaldo Carvalho de Melo:

 - Add missing fields and remove some duplicate fields when printing a
   perf_event_attr.

 - Fix hybrid config terms list corruption.

 - Update kernel header copies, some resulted in new kernel features
   being automagically added to 'perf trace' syscall/tracepoint argument
   id->string translators.

 - Add a file generated during the documentation build to .gitignore.

 - Add an option to build without libbfd, as some distros, like Debian
   consider its ABI unstable.

 - Add support to print a textual representation of IBS raw sample data
   in 'perf report'.

 - Fix bpf 'perf test' sample mismatch reporting

 - Fix passing arguments to stackcollapse report in a 'perf script'
   python script.

 - Allow build-id with trailing zeros.

 - Look for ImageBase in PE file to compute .text offset.

* tag 'perf-tools-for-v5.15-2021-09-11' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (25 commits)
  tools headers UAPI: Update tools's copy of drm.h headers
  tools headers UAPI: Sync drm/i915_drm.h with the kernel sources
  tools headers UAPI: Sync linux/fs.h with the kernel sources
  tools headers UAPI: Sync linux/in.h copy with the kernel sources
  perf tools: Add an option to build without libbfd
  perf tools: Allow build-id with trailing zeros
  perf tools: Fix hybrid config terms list corruption
  perf tools: Factor out copy_config_terms() and free_config_terms()
  perf tools: Fix perf_event_attr__fprintf() missing/dupl. fields
  perf tools: Ignore Documentation dependency file
  perf bpf: Provide a weak btf__load_from_kernel_by_id() for older libbpf versions
  tools include UAPI: Update linux/mount.h copy
  perf beauty: Cover more flags in the  move_mount syscall argument beautifier
  tools headers UAPI: Sync linux/prctl.h with the kernel sources
  tools include UAPI: Sync sound/asound.h copy with the kernel sources
  tools headers UAPI: Sync linux/kvm.h with the kernel sources
  tools headers UAPI: Sync x86's asm/kvm.h with the kernel sources
  perf report: Add support to print a textual representation of IBS raw sample data
  perf report: Add tools/arch/x86/include/asm/amd-ibs.h
  perf env: Add perf_env__cpuid, perf_env__{nr_}pmu_mappings
  ...

Pull compiler attributes updates from Miguel Ojeda:

 - Fix __has_attribute(__no_sanitize_coverage__) for GCC 4 (Marco Elver)

 - Add Nick as Reviewer for compiler_attributes.h (Nick Desaulniers)

 - Move __compiletime_{error|warning} (Nick Desaulniers)

* tag 'compiler-attributes-for-linus-v5.15-rc1-v2' of git://github.com/ojeda/linux:
  compiler_attributes.h: move __compiletime_{error|warning}
  MAINTAINERS: add Nick as Reviewer for compiler_attributes.h
  Compiler Attributes: fix __has_attribute(__no_sanitize_coverage__) for GCC 4

Pull auxdisplay updates from Miguel Ojeda:
 "An assortment of improvements for auxdisplay:

   - Replace symbolic permissions with octal permissions (Jinchao Wang)

   - ks0108: Switch to use module_parport_driver() (Andy Shevchenko)

   - charlcd: Drop unneeded initializers and switch to C99 style (Andy
     Shevchenko)

   - hd44780: Fix oops on module unloading (Lars Poeschel)

   - Add I2C gpio expander example (Ralf Schlatterbeck)"

* tag 'auxdisplay-for-linus-v5.15-rc1' of git://github.com/ojeda/linux:
  auxdisplay: Replace symbolic permissions with octal permissions
  auxdisplay: ks0108: Switch to use module_parport_driver()
  auxdisplay: charlcd: Drop unneeded initializers and switch to C99 style
  auxdisplay: hd44780: Fix oops on module unloading
  auxdisplay: Add I2C gpio expander example

Pull CPU hotplug updates from Thomas Gleixner:
 "Updates for the SMP and CPU hotplug:

   - Remove DEFINE_SMP_CALL_CACHE_FUNCTION() which is a left over of the
     original hotplug code and now causing trouble with the ARM64 cache
     topology setup due to the pointless SMP function call.

     It's not longer required as the hotplug callbacks are guaranteed to
     be invoked on the upcoming CPU.

   - Remove the deprecated and now unused CPU hotplug functions

   - Rewrite the CPU hotplug API documentation"

* tag 'smp-urgent-2021-09-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Documentation: core-api/cpuhotplug: Rewrite the API section
  cpu/hotplug: Remove deprecated CPU-hotplug functions.
  thermal: Replace deprecated CPU-hotplug functions.
  drivers: base: cacheinfo: Get rid of DEFINE_SMP_CALL_CACHE_FUNCTION()

Merge tag 'char-misc-5.15-rc1-lkdtm' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull misc driver fix from Greg KH:
 "Here is a single patch for 5.15-rc1, for the lkdtm misc driver.

  It resolves a build issue that many people were hitting with your
  current tree, and Kees and others felt would be good to get merged
  before -rc1 comes out, to prevent them from having to constantly hit
  it as many development trees restart on -rc1, not older -rc releases.

  It has NOT been in linux-next, but has passed 0-day testing and looks
  'obviously correct' when reviewing it locally :)"

* tag 'char-misc-5.15-rc1-lkdtm' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  lkdtm: Use init_uts_ns.name instead of macros