linux-stable.git/drivers/block, branch v4.4.172

loop: Fix double mutex_unlock(&loop_ctl_mutex) in loop_control_ioctl()

2019-01-26T08:42:52+00:00

commit 628bd85947091830a8c4872adfd5ed1d515a9cf2 upstream.

Commit 0a42e99b58a20883 ("loop: Get rid of loop_index_mutex") forgot to
remove mutex_unlock(&loop_ctl_mutex) from loop_control_ioctl() when
replacing loop_index_mutex with loop_ctl_mutex.

Fixes: 0a42e99b58a20883 ("loop: Get rid of loop_index_mutex")
Reported-by: syzbot 
Reviewed-by: Ming Lei 
Reviewed-by: Jan Kara 
Signed-off-by: Tetsuo Handa 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

loop: Get rid of loop_index_mutex

2019-01-26T08:42:52+00:00

commit 0a42e99b58a208839626465af194cfe640ef9493 upstream.

Now that loop_ctl_mutex is global, just get rid of loop_index_mutex as
there is no good reason to keep these two separate and it just
complicates the locking.

Signed-off-by: Jan Kara 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

loop: Fold __loop_release into loop_release

2019-01-26T08:42:51+00:00

commit 967d1dc144b50ad005e5eecdfadfbcfb399ffff6 upstream.

__loop_release() has a single call site. Fold it there. This is
currently not a huge win but it will make following replacement of
loop_index_mutex more obvious.

Signed-off-by: Jan Kara 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

block/loop: Use global lock for ioctl() operation.

2019-01-26T08:42:51+00:00

commit 310ca162d779efee8a2dc3731439680f3e9c1e86 upstream.

syzbot is reporting NULL pointer dereference [1] which is caused by
race condition between ioctl(loop_fd, LOOP_CLR_FD, 0) versus
ioctl(other_loop_fd, LOOP_SET_FD, loop_fd) due to traversing other
loop devices at loop_validate_file() without holding corresponding
lo->lo_ctl_mutex locks.

Since ioctl() request on loop devices is not frequent operation, we don't
need fine grained locking. Let's use global lock in order to allow safe
traversal at loop_validate_file().

Note that syzbot is also reporting circular locking dependency between
bdev->bd_mutex and lo->lo_ctl_mutex [2] which is caused by calling
blkdev_reread_part() with lock held. This patch does not address it.

[1] https://syzkaller.appspot.com/bug?id=f3cfe26e785d85f9ee259f385515291d21bd80a3
[2] https://syzkaller.appspot.com/bug?id=bf154052f0eea4bc7712499e4569505907d15889

Signed-off-by: Tetsuo Handa 
Reported-by: syzbot 
Reviewed-by: Jan Kara 
Signed-off-by: Jan Kara 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

zram: close udev startup race condition as default groups

2018-11-27T15:08:01+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 
Signed-off-by: Sasha Levin

swim: fix cleanup on setup error

2018-11-21T08:27:31+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

2018-11-21T08:27:31+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

floppy: Do not copy a kernel pointer to user memory in FDGETPRM ioctl

2018-10-10T06:52:07+00:00

commit 65eea8edc315589d6c993cf12dbb5d0e9ef1fe4e upstream.

The final field of a floppy_struct is the field "name", which is a pointer
to a string in kernel memory.  The kernel pointer should not be copied to
user memory.  The FDGETPRM ioctl copies a floppy_struct to user memory,
including this "name" field.  This pointer cannot be used by the user
and it will leak a kernel address to user-space, which will reveal the
location of kernel code and data and undermine KASLR protection.

Model this code after the compat ioctl which copies the returned data
to a previously cleared temporary structure on the stack (excluding the
name pointer) and copy out to userspace from there.  As we already have
an inparam union with an appropriate member and that memory is already
cleared even for read only calls make use of that as a temporary store.

Based on an initial patch by Brian Belleville.

CVE-2018-7755
Signed-off-by: Andy Whitcroft 
Broke up long line.
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

loop: remember whether sysfs_create_group() was done

2018-07-17T09:31:46+00:00

commit d3349b6b3c373ac1fbfb040b810fcee5e2adc7e0 upstream.

syzbot is hitting WARN() triggered by memory allocation fault
injection [1] because loop module is calling sysfs_remove_group()
when sysfs_create_group() failed.
Fix this by remembering whether sysfs_create_group() succeeded.

[1] https://syzkaller.appspot.com/bug?id=3f86c0edf75c86d2633aeb9dd69eccc70bc7e90b

Signed-off-by: Tetsuo Handa 
Reported-by: syzbot 
Reviewed-by: Greg Kroah-Hartman 

Renamed sysfs_ready -> sysfs_inited.

Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

loop: add recursion validation to LOOP_CHANGE_FD

2018-07-17T09:31:46+00:00

commit d2ac838e4cd7e5e9891ecc094d626734b0245c99 upstream.

Refactor the validation code used in LOOP_SET_FD so it is also used in
LOOP_CHANGE_FD.  Otherwise it is possible to construct a set of loop
devices that all refer to each other.  This can lead to a infinite
loop in starting with "while (is_loop_device(f)) .." in loop_set_fd().

Fix this by refactoring out the validation code and using it for
LOOP_CHANGE_FD as well as LOOP_SET_FD.

Reported-by: syzbot+4349872271ece473a7c91190b68b4bac7c5dbc87@syzkaller.appspotmail.com
Reported-by: syzbot+40bd32c4d9a3cc12a339@syzkaller.appspotmail.com
Reported-by: syzbot+769c54e66f994b041be7@syzkaller.appspotmail.com
Reported-by: syzbot+0a89a9ce473936c57065@syzkaller.appspotmail.com
Signed-off-by: Theodore Ts'o 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman