linux-stable.git/drivers/block/floppy.c, branch v5.0

floppy: check_events callback should not return a negative number

2019-02-12T16:13:18+00:00

floppy_check_events() is supposed to return bit flags to say which
events occured. We should return zero to say that no event flags are
set.  Only BIT(0) and BIT(1) are used in the caller. And .check_events
interface also expect to return an unsigned int value.

However, after commit a0c80efe5956, it may return -EINTR (-4u).
Here, both BIT(0) and BIT(1) are cleared. So this patch shouldn't
affect runtime, but it obviously is still worth fixing.

Reviewed-by: Dan Carpenter 
Fixes: a0c80efe5956 ("floppy: fix lock_fdc() signal handling")
Signed-off-by: Yufen Yu 
Signed-off-by: Jens Axboe

Merge tag 'v4.20-rc3' into for-4.21/block

2018-11-18T22:46:03+00:00

Merge in -rc3 to resolve a few conflicts, but also to get a few
important fixes that have gone into mainline since the block
4.21 branch was forked off (most notably the SCSI queue issue,
which is both a conflict AND needed fix).

Signed-off-by: Jens Axboe

floppy: remove now unused 'flags' variable

2018-11-18T22:42:48+00:00

With the locking removed, it's unused. Kill it.

Fixes: 503f620f0cb8 ("floppy: remove queue_lock around floppy_end_request")
Signed-off-by: Jens Axboe

floppy: remove queue_lock around floppy_end_request

2018-11-16T16:16:57+00:00

There is nothing the queue_lock could protect inside floppy_end_request,
so remove it.

Reviewed-by: Omar Sandoval 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: remove the queue_lock indirection

2018-11-15T19:17:28+00:00

With the legacy request path gone there is no good reason to keep
queue_lock as a pointer, we can always use the embedded lock now.

Reviewed-by: Hannes Reinecke 
Signed-off-by: Christoph Hellwig 

Fixed floppy and blk-cgroup missing conversions and half done edits.

Signed-off-by: Jens Axboe

floppy: fix race condition in __floppy_read_block_0()

2018-11-10T15:16:12+00:00

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

floppy: convert to blk-mq

2018-10-16T15:50:14+00:00

This driver likes to fetch requests from all over the place, so make
queue_rq put requests on a list so that the logic stays the same. Tested
with QEMU.

Signed-off-by: Omar Sandoval 

Converted to blk_mq_init_sq_queue() and fixed a few spots where the
tag_set leaked on cleanup.

Signed-off-by: Jens Axboe

Merge tag 'v4.19-rc6' into for-4.20/block

2018-10-01T14:58:57+00:00

Merge -rc6 in, for two reasons:

1) Resolve a trivial conflict in the blk-mq-tag.c documentation
2) A few important regression fixes went into upstream directly, so
   they aren't in the 4.20 branch.

Signed-off-by: Jens Axboe 

* tag 'v4.19-rc6': (780 commits)
  Linux 4.19-rc6
  MAINTAINERS: fix reference to moved drivers/{misc => auxdisplay}/panel.c
  cpufreq: qcom-kryo: Fix section annotations
  perf/core: Add sanity check to deal with pinned event failure
  xen/blkfront: correct purging of persistent grants
  Revert "xen/blkfront: When purging persistent grants, keep them in the buffer"
  selftests/powerpc: Fix Makefiles for headers_install change
  blk-mq: I/O and timer unplugs are inverted in blktrace
  dax: Fix deadlock in dax_lock_mapping_entry()
  x86/boot: Fix kexec booting failure in the SEV bit detection code
  bcache: add separate workqueue for journal_write to avoid deadlock
  drm/amd/display: Fix Edid emulation for linux
  drm/amd/display: Fix Vega10 lightup on S3 resume
  drm/amdgpu: Fix vce work queue was not cancelled when suspend
  Revert "drm/panel: Add device_link from panel device to DRM device"
  xen/blkfront: When purging persistent grants, keep them in the buffer
  clocksource/drivers/timer-atmel-pit: Properly handle error cases
  block: fix deadline elevator drain for zoned block devices
  ACPI / hotplug / PCI: Don't scan for non-hotplug bridges if slot is not bridge
  drm/syncobj: Don't leak fences when WAIT_FOR_SUBMIT is set
  ...

Signed-off-by: Jens Axboe

block: genhd: add 'groups' argument to device_add_disk

2018-09-28T14:30:28+00:00

Update device_add_disk() to take an 'groups' argument so that
individual drivers can register a device with additional sysfs
attributes.
This avoids race condition the driver would otherwise have if these
groups were to be created with sysfs_add_groups().

Signed-off-by: Martin Wilck 
Signed-off-by: Hannes Reinecke 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Bart Van Assche 
Signed-off-by: Jens Axboe

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

2018-09-20T15:09:48+00:00

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