linux-stable.git/drivers/block, branch v4.8.13

zram: fix unbalanced idr management at hot removal

2016-12-08T06:16:18+00:00

commit 529e71e16403830ae0d737a66c55c5f360f3576b upstream.

The zram hot removal code calls idr_remove() even when zram_remove()
returns an error (typically -EBUSY).  This results in a leftover at the
device release, eventually leading to a crash when the module is
reloaded.

As described in the bug report below, the following procedure would
cause an Oops with zram:

 - provision three zram devices via modprobe zram num_devices=3
 - configure a size for each device
   + echo "1G" > /sys/block/$zram_name/disksize
 - mkfs and mount zram0 only
 - attempt to hot remove all three devices
   + echo 2 > /sys/class/zram-control/hot_remove
   + echo 1 > /sys/class/zram-control/hot_remove
   + echo 0 > /sys/class/zram-control/hot_remove
     - zram0 removal fails with EBUSY, as expected
 - unmount zram0
 - try zram0 hot remove again
   + echo 0 > /sys/class/zram-control/hot_remove
     - fails with ENODEV (unexpected)
 - unload zram kernel module
   + completes successfully
 - zram0 device node still exists
 - attempt to mount /dev/zram0
   + mount command is killed
   + following BUG is encountered

 BUG: unable to handle kernel paging request at ffffffffa0002ba0
 IP: get_disk+0x16/0x50
 Oops: 0000 [#1] SMP
 CPU: 0 PID: 252 Comm: mount Not tainted 4.9.0-rc6 #176
 Call Trace:
   exact_lock+0xc/0x20
   kobj_lookup+0xdc/0x160
   get_gendisk+0x2f/0x110
   __blkdev_get+0x10c/0x3c0
   blkdev_get+0x19d/0x2e0
   blkdev_open+0x56/0x70
   do_dentry_open.isra.19+0x1ff/0x310
   vfs_open+0x43/0x60
   path_openat+0x2c9/0xf30
   do_filp_open+0x79/0xd0
   do_sys_open+0x114/0x1e0
   SyS_open+0x19/0x20
   entry_SYSCALL_64_fastpath+0x13/0x94

This patch adds the proper error check in hot_remove_store() not to call
idr_remove() unconditionally.

Fixes: 17ec4cd98578 ("zram: don't call idr_remove() from zram_remove()")
Bugzilla: https://bugzilla.opensuse.org/show_bug.cgi?id=1010970
Link: http://lkml.kernel.org/r/20161121132140.12683-1-tiwai@suse.de
Signed-off-by: Takashi Iwai 
Reviewed-by: David Disseldorp 
Reported-by: David Disseldorp 
Tested-by: David Disseldorp 
Acked-by: Minchan Kim 
Acked-by: Sergey Senozhatsky 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

drbd: Fix kernel_sendmsg() usage - potential NULL deref

2016-11-18T09:51:47+00:00

commit d8e9e5e80e882b4f90cba7edf1e6cb7376e52e54 upstream.

Don't pass a size larger than iov_len to kernel_sendmsg().
Otherwise it will cause a NULL pointer deref when kernel_sendmsg()
returns with rv < size.

DRBD as external module has been around in the kernel 2.4 days already.
We used to be compatible to 2.4 and very early 2.6 kernels,
we used to use
 rv = sock_sendmsg(sock, &msg, iov.iov_len);
then later changed to
 rv = kernel_sendmsg(sock, &msg, &iov, 1, size);
when we should have used
 rv = kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);

tcp_sendmsg() used to totally ignore the size parameter.
 57be5bd ip: convert tcp_sendmsg() to iov_iter primitives
changes that, and exposes our long standing error.

Even with this error exposed, to trigger the bug, we would need to have
an environment (config or otherwise) causing us to not use sendpage()
for larger transfers, a failing connection, and have it fail "just at the
right time".  Apparently that was unlikely enough for most, so this went
unnoticed for years.

Still, it is known to trigger at least some of these,
and suspected for the others:
[0] http://lists.linbit.com/pipermail/drbd-user/2016-July/023112.html
[1] http://lists.linbit.com/pipermail/drbd-dev/2016-March/003362.html
[2] https://forums.grsecurity.net/viewtopic.php?f=3&t=4546
[3] https://ubuntuforums.org/showthread.php?t=2336150
[4] http://e2.howsolveproblem.com/i/1175162/

This should go into 4.9,
and into all stable branches since and including v4.0,
which is the first to contain the exposing change.

It is correct for all stable branches older than that as well
(which contain the DRBD driver; which is 2.6.33 and up).

It requires a small "conflict" resolution for v4.4 and earlier, with v4.5
we dropped the comment block immediately preceding the kernel_sendmsg().

Fixes: b411b3637fa7 ("The DRBD driver")
Cc: viro@zeniv.linux.org.uk
Cc: christoph.lechleitner@iteg.at
Cc: wolfgang.glas@iteg.at
Reported-by: Christoph Lechleitner 
Tested-by: Christoph Lechleitner 
Signed-off-by: Richard Weinberger 
[changed oneliner to be "obvious" without context; more verbose message]
Signed-off-by: Lars Ellenberg 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

Revert "floppy: refactor open() flags handling"

2016-08-25T14:56:51+00:00

This reverts commit 09954bad448791ef01202351d437abdd9497a804.

Revert "floppy: fix open(O_ACCMODE) for ioctl-only open"

2016-08-25T14:56:44+00:00

This reverts commit ff06db1efb2ad6db06eb5b99b88a0c15a9cc9b0e.

xen-blkfront: free resources if xlvbd_alloc_gendisk fails

2016-08-19T16:31:59+00:00

Current code forgets to free resources in the failure path of
xlvbd_alloc_gendisk(), this patch fix it.

Signed-off-by: Bob Liu 
Signed-off-by: Konrad Rzeszutek Wilk

xen-blkfront: introduce blkif_set_queue_limits()

2016-08-19T16:31:59+00:00

blk_mq_update_nr_hw_queues() reset all queue limits to default which it's
not as xen-blkfront expected, introducing blkif_set_queue_limits() to reset
limits with initial correct values.

Signed-off-by: Bob Liu 
Acked-by: Roger Pau Monné 
Signed-off-by: Konrad Rzeszutek Wilk

xen-blkfront: fix places not updated after introducing 64KB page granularity

2016-08-19T16:31:58+00:00

Two places didn't get updated when 64KB page granularity was introduced,
this patch fix them.

Signed-off-by: Bob Liu 
Acked-by: Roger Pau Monné 
Signed-off-by: Konrad Rzeszutek Wilk

Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

2016-08-11T21:10:23+00:00

Pull virtio/vhost fixes and cleanups from Michael Tsirkin:
 "Misc fixes and cleanups all over the place"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio/s390: deprecate old transport
  virtio/s390: keep early_put_chars
  virtio_blk: Fix a slient kernel panic
  virtio-vsock: fix include guard typo
  vhost/vsock: fix vhost virtio_vsock_pkt use-after-free
  9p/trans_virtio: use kvfree() for iov_iter_get_pages_alloc()
  virtio: fix error handling for debug builds
  virtio: fix memory leak in virtqueue_add()

rbd: nuke the 32-bit pool id check

2016-08-09T15:26:47+00:00

ceph_file_layout::pool_id is now s64.  rbd_add_get_pool_id() and
ceph_pg_poolid_by_name() both return an int, so it's bogus anyway.

Signed-off-by: Ilya Dryomov 
Reviewed-by: Alex Elder

virtio_blk: Fix a slient kernel panic

2016-08-09T10:42:39+00:00

We do a lot of memory allocation in function init_vq, and don't handle
the allocation failure properly. Then this function will return 0,
although initialization fails due to lacking memory. At that moment,
kernel will panic in guest machine, if virtio is used to drive disk.

To fix this bug, we should take care of allocation failure, and return
correct value to let caller know what happen.

Tested-by: Chao Fan 
Signed-off-by: Minfei Huang 
Signed-off-by: Minfei Huang 
Reviewed-by: Cornelia Huck 
Reviewed-by: Stefan Hajnoczi 
Signed-off-by: Michael S. Tsirkin