linux-toradex.git/drivers/block, branch toradex_4.19.y

floppy: fix race condition in __floppy_read_block_0()

2018-12-01T08:37:32+00:00

[ Upstream commit de7b75d82f70c5469675b99ad632983c50b6f7e7 ]

LKP recently reported a hang at bootup in the floppy code:

[  245.678853] INFO: task mount:580 blocked for more than 120 seconds.
[  245.679906]       Tainted: G                T 4.19.0-rc6-00172-ga9f38e1 #1
[  245.680959] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  245.682181] mount           D 6372   580      1 0x00000004
[  245.683023] Call Trace:
[  245.683425]  __schedule+0x2df/0x570
[  245.683975]  schedule+0x2d/0x80
[  245.684476]  schedule_timeout+0x19d/0x330
[  245.685090]  ? wait_for_common+0xa5/0x170
[  245.685735]  wait_for_common+0xac/0x170
[  245.686339]  ? do_sched_yield+0x90/0x90
[  245.686935]  wait_for_completion+0x12/0x20
[  245.687571]  __floppy_read_block_0+0xfb/0x150
[  245.688244]  ? floppy_resume+0x40/0x40
[  245.688844]  floppy_revalidate+0x20f/0x240
[  245.689486]  check_disk_change+0x43/0x60
[  245.690087]  floppy_open+0x1ea/0x360
[  245.690653]  __blkdev_get+0xb4/0x4d0
[  245.691212]  ? blkdev_get+0x1db/0x370
[  245.691777]  blkdev_get+0x1f3/0x370
[  245.692351]  ? path_put+0x15/0x20
[  245.692871]  ? lookup_bdev+0x4b/0x90
[  245.693539]  blkdev_get_by_path+0x3d/0x80
[  245.694165]  mount_bdev+0x2a/0x190
[  245.694695]  squashfs_mount+0x10/0x20
[  245.695271]  ? squashfs_alloc_inode+0x30/0x30
[  245.695960]  mount_fs+0xf/0x90
[  245.696451]  vfs_kern_mount+0x43/0x130
[  245.697036]  do_mount+0x187/0xc40
[  245.697563]  ? memdup_user+0x28/0x50
[  245.698124]  ksys_mount+0x60/0xc0
[  245.698639]  sys_mount+0x19/0x20
[  245.699167]  do_int80_syscall_32+0x61/0x130
[  245.699813]  entry_INT80_32+0xc7/0xc7

showing that we never complete that read request. The reason is that
the completion setup is racy - it initializes the completion event
AFTER submitting the IO, which means that the IO could complete
before/during the init. If it does, we are passing garbage to
complete() and we may sleep forever waiting for the event to
occur.

Fixes: 7b7b68bba5ef ("floppy: bail out in open() if drive is not responding to block0 read")
Reviewed-by: Omar Sandoval 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: brd: associate with queue until adding disk

2018-11-27T15:12:58+00:00

[ Upstream commit 153fcd5f6d93b8e1e4040b1337f564a10f8d93af ]

brd_free() may be called in failure path on one brd instance which
disk isn't added yet, so release handler of gendisk may free the
associated request_queue early and causes the following use-after-free[1].

This patch fixes this issue by associating gendisk with request_queue
just before adding disk.

[1] KASAN: use-after-free Read in del_timer_syncNon-volatile memory driver v1.3
Linux agpgart interface v0.103
[drm] Initialized vgem 1.0.0 20120112 for virtual device on minor 0
usbcore: registered new interface driver udl
==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x36d9/0x4c20
kernel/locking/lockdep.c:3218
Read of size 8 at addr ffff8801d1b6b540 by task swapper/0/1

CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.0+ #88
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x244/0x39d lib/dump_stack.c:113
  print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256
  kasan_report_error mm/kasan/report.c:354 [inline]
  kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412
  __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
  __lock_acquire+0x36d9/0x4c20 kernel/locking/lockdep.c:3218
  lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844
  del_timer_sync+0xb7/0x270 kernel/time/timer.c:1283
  blk_cleanup_queue+0x413/0x710 block/blk-core.c:809
  brd_free+0x5d/0x71 drivers/block/brd.c:422
  brd_init+0x2eb/0x393 drivers/block/brd.c:518
  do_one_initcall+0x145/0x957 init/main.c:890
  do_initcall_level init/main.c:958 [inline]
  do_initcalls init/main.c:966 [inline]
  do_basic_setup init/main.c:984 [inline]
  kernel_init_freeable+0x5c6/0x6b9 init/main.c:1148
  kernel_init+0x11/0x1ae init/main.c:1068
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:350

Reported-by: syzbot+3701447012fe951dabb2@syzkaller.appspotmail.com
Signed-off-by: Ming Lei 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

zram: close udev startup race condition as default groups

2018-11-21T08:19:15+00:00

commit fef912bf860e upstream.
commit 98af4d4df889 upstream.

I got a report from Howard Chen that he saw zram and sysfs race(ie,
zram block device file is created but sysfs for it isn't yet)
when he tried to create new zram devices via hotadd knob.

v4.20 kernel fixes it by [1, 2] but it's too large size to merge
into -stable so this patch fixes the problem by registering defualt
group by Greg KH's approach[3].

This patch should be applied to every stable tree [3.16+] currently
existing from kernel.org because the problem was introduced at 2.6.37
by [4].

[1] fef912bf860e, block: genhd: add 'groups' argument to device_add_disk
[2] 98af4d4df889, zram: register default groups with device_add_disk()
[3] http://kroah.com/log/blog/2013/06/26/how-to-create-a-sysfs-file-correctly/
[4] 33863c21e69e9, Staging: zram: Replace ioctls with sysfs interface

Cc: Sergey Senozhatsky 
Cc: Hannes Reinecke 
Tested-by: Howard Chen 
Signed-off-by: Minchan Kim 
Reviewed-by: Hannes Reinecke 
Signed-off-by: Sasha Levin

xen-blkfront: fix kernel panic with negotiate_mq error path

2018-11-13T19:08:53+00:00

commit 6cc4a0863c9709c512280c64e698d68443ac8053 upstream.

info->nr_rings isn't adjusted in case of ENOMEM error from
negotiate_mq(). This leads to kernel panic in error path.

Typical call stack involving panic -
 #8 page_fault at ffffffff8175936f
    [exception RIP: blkif_free_ring+33]
    RIP: ffffffffa0149491  RSP: ffff8804f7673c08  RFLAGS: 00010292
 ...
 #9 blkif_free at ffffffffa0149aaa [xen_blkfront]
 #10 talk_to_blkback at ffffffffa014c8cd [xen_blkfront]
 #11 blkback_changed at ffffffffa014ea8b [xen_blkfront]
 #12 xenbus_otherend_changed at ffffffff81424670
 #13 backend_changed at ffffffff81426dc3
 #14 xenwatch_thread at ffffffff81422f29
 #15 kthread at ffffffff810abe6a
 #16 ret_from_fork at ffffffff81754078

Cc: stable@vger.kernel.org
Fixes: 7ed8ce1c5fc7 ("xen-blkfront: move negotiate_mq to cover all cases of new VBDs")
Signed-off-by: Manjunath Patil 
Acked-by: Roger Pau Monné 
Signed-off-by: Juergen Gross 
Signed-off-by: Greg Kroah-Hartman

xen/blkfront: avoid NULL blkfront_info dereference on device removal

2018-11-13T19:08:40+00:00

commit f92898e7f32e3533bfd95be174044bc349d416ca upstream.

If a block device is hot-added when we are out of grants,
gnttab_grant_foreign_access fails with -ENOSPC (log message "28
granting access to ring page") in this code path:

  talk_to_blkback ->
	setup_blkring ->
		xenbus_grant_ring ->
			gnttab_grant_foreign_access

and the failing path in talk_to_blkback sets the driver_data to NULL:

 destroy_blkring:
        blkif_free(info, 0);

        mutex_lock(&blkfront_mutex);
        free_info(info);
        mutex_unlock(&blkfront_mutex);

        dev_set_drvdata(&dev->dev, NULL);

This results in a NULL pointer BUG when blkfront_remove and blkif_free
try to access the failing device's NULL struct blkfront_info.

Cc: stable@vger.kernel.org # 4.5 and later
Signed-off-by: Vasilis Liaskovitis 
Reviewed-by: Roger Pau Monné 
Signed-off-by: Konrad Rzeszutek Wilk 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

swim: fix cleanup on setup error

2018-11-13T19:08:20+00:00

[ Upstream commit 1448a2a5360ae06f25e2edc61ae070dff5c0beb4 ]

If we fail to allocate the request queue for a disk, we still need to
free that disk, not just the previous ones. Additionally, we need to
cleanup the previous request queues.

Signed-off-by: Omar Sandoval 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ataflop: fix error handling during setup

2018-11-13T19:08:20+00:00

[ Upstream commit 71327f547ee3a46ec5c39fdbbd268401b2578d0e ]

Move queue allocation next to disk allocation to fix a couple of issues:

- If add_disk() hasn't been called, we should clear disk->queue before
  calling put_disk().
- If we fail to allocate a request queue, we still need to put all of
  the disks, not just the ones that we allocated queues for.

Signed-off-by: Omar Sandoval 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

sunvdc: Remove VLA usage

2018-10-08T18:09:34+00:00

In the quest to remove all stack VLA usage from the kernel[1], this moves
the math for cookies calculation into macros and allocates a fixed size
array for the maximum number of cookies and adds a runtime sanity check.
(Note that the size was always fixed, but just hidden from the compiler.)

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com

Cc: Jens Axboe 
Cc: linux-block@vger.kernel.org
Signed-off-by: Kees Cook 
Signed-off-by: David S. Miller

Merge tag 'for-linus-20180929' of git://git.kernel.dk/linux-block

2018-09-29T21:52:14+00:00

Jens writes:
  "Block fixes for 4.19-rc6

   A set of fixes that should go into this release. This pull request
   contains:

   - A fix (hopefully) for the persistent grants for xen-blkfront. A
     previous fix from this series wasn't complete, hence reverted, and
     this one should hopefully be it. (Boris Ostrovsky)

   - Fix for an elevator drain warning with SMR devices, which is
     triggered when you switch schedulers (Damien)

   - bcache deadlock fix (Guoju Fang)

   - Fix for the block unplug tracepoint, which has had the
     timer/explicit flag reverted since 4.11 (Ilya)

   - Fix a regression in this series where the blk-mq timeout hook is
     invoked with the RCU read lock held, hence preventing it from
     blocking (Keith)

   - NVMe pull from Christoph, with a single multipath fix (Susobhan Dey)"

* tag 'for-linus-20180929' of git://git.kernel.dk/linux-block:
  xen/blkfront: correct purging of persistent grants
  Revert "xen/blkfront: When purging persistent grants, keep them in the buffer"
  blk-mq: I/O and timer unplugs are inverted in blktrace
  bcache: add separate workqueue for journal_write to avoid deadlock
  xen/blkfront: When purging persistent grants, keep them in the buffer
  block: fix deadline elevator drain for zoned block devices
  blk-mq: Allow blocking queue tag iter callbacks
  nvme: properly propagate errors in nvme_mpath_init

xen/blkfront: correct purging of persistent grants

2018-09-28T15:40:39+00:00

Commit a46b53672b2c2e3770b38a4abf90d16364d2584b ("xen/blkfront: cleanup
stale persistent grants") introduced a regression as purged persistent
grants were not pu into the list of free grants again. Correct that.

Reviewed-by: Boris Ostrovsky 
Signed-off-by: Juergen Gross 
Signed-off-by: Jens Axboe