linux-toradex.git/drivers/md/dm-ioctl.c, branch v6.11

dm resume: don't return EINVAL when signalled

2024-08-13T11:51:34+00:00

If the dm_resume method is called on a device that is not suspended, the
method will suspend the device briefly, before resuming it (so that the
table will be swapped).

However, there was a bug that the return value of dm_suspended_md was not
checked. dm_suspended_md may return an error when it is interrupted by a
signal. In this case, do_resume would call dm_swap_table, which would
return -EINVAL.

This commit fixes the logic, so that error returned by dm_suspend is
checked and the resume operation is undone.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Khazhismel Kumykov 
Cc: stable@vger.kernel.org

dm ioctl: update DM_DRIVER_EMAIL to new dm-devel mailing list

2024-02-20T19:22:55+00:00

Fixes: 3da5d2de9238 ("MAINTAINERS: update the dm-devel mailing list")
Signed-off-by: Mike Snitzer

dm: limit the number of targets and parameter size area

2024-01-30T19:05:02+00:00

The kvmalloc function fails with a warning if the size is larger than
INT_MAX. The warning was triggered by a syscall testing robot.

In order to avoid the warning, this commit limits the number of targets to
1048576 and the size of the parameter area to 1073741824.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer

dm ioctl: replace deprecated strncpy with strscpy_pad

2023-10-23T17:02:37+00:00

`strncpy` is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.

We expect `spec->target_type` to be NUL-terminated based on its use with
a format string after `dm_table_add_target()` is called
| 	r = dm_table_add_target(table, spec->target_type,
| 				(sector_t) spec->sector_start,
| 				(sector_t) spec->length,
| 				target_params);
... wherein `spec->target_type` is passed as parameter `type` and later
printed with DMERR:
|       DMERR("%s: %s: unknown target type", dm_device_name(t->md), type);

It appears that `spec` is not zero-allocated and thus NUL-padding may be
required in this ioctl context.

Considering the above, a suitable replacement is `strscpy_pad` due to
the fact that it guarantees NUL-termination whilst maintaining the
NUL-padding behavior that strncpy provides.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://github.com/KSPP/linux/issues/90
Reviewed-by: Kees Cook 
Signed-off-by: Justin Stitt 
Signed-off-by: Mike Snitzer

dm: fix a race condition in retrieve_deps

2023-09-14T15:18:29+00:00

There's a race condition in the multipath target when retrieve_deps
races with multipath_message calling dm_get_device and dm_put_device.
retrieve_deps walks the list of open devices without holding any lock
but multipath may add or remove devices to the list while it is
running. The end result may be memory corruption or use-after-free
memory access.

See this description of a UAF with multipath_message():
https://listman.redhat.com/archives/dm-devel/2022-October/052373.html

Fix this bug by introducing a new rw semaphore "devices_lock". We grab
devices_lock for read in retrieve_deps and we grab it for write in
dm_get_device and dm_put_device.

Reported-by: Luo Meng 
Signed-off-by: Mikulas Patocka 
Cc: stable@vger.kernel.org
Tested-by: Li Lingfeng 
Signed-off-by: Mike Snitzer

Merge tag 'for-6.5/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

2023-06-30T19:16:00+00:00

Pull device mapper updates from Mike Snitzer:

 - Update DM crypt to allocate compound pages if possible

 - Fix DM crypt target's crypt_ctr_cipher_new return value on invalid
   AEAD cipher

 - Fix DM flakey testing target's write bio corruption feature to
   corrupt the data of a cloned bio instead of the original

 - Add random_read_corrupt and random_write_corrupt features to DM
   flakey target

 - Fix ABBA deadlock in DM thin metadata by resetting associated bufio
   client rather than destroying and recreating it

 - A couple other small DM thinp cleanups

 - Update DM core to support disabling block core IO stats accounting
   and optimize away code that isn't needed if stats are disabled

 - Other small DM core cleanups

 - Improve DM integrity target to not require so much memory on 32 bit
   systems. Also only allocate the recalculate buffer as needed (and
   increasingly reduce its size on allocation failure)

 - Update DM integrity to use %*ph for printing hexdump of a small
   buffer. Also update DM integrity documentation

 - Various DM core ioctl interface hardening. Now more careful about
   alignment of structures and processing of input passed to the kernel
   from userspace.

   Also disallow the creation of DM devices named "control", "." or ".."

 - Eliminate GFP_NOIO workarounds for __vmalloc and kvmalloc in DM
   core's ioctl and bufio code

* tag 'for-6.5/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (28 commits)
  dm: get rid of GFP_NOIO workarounds for __vmalloc and kvmalloc
  dm integrity: scale down the recalculate buffer if memory allocation fails
  dm integrity: only allocate recalculate buffer when needed
  dm integrity: reduce vmalloc space footprint on 32-bit architectures
  dm ioctl: Refuse to create device named "." or ".."
  dm ioctl: Refuse to create device named "control"
  dm ioctl: Avoid double-fetch of version
  dm ioctl: structs and parameter strings must not overlap
  dm ioctl: Avoid pointer arithmetic overflow
  dm ioctl: Check dm_target_spec is sufficiently aligned
  Documentation: dm-integrity: Document an example of how the tunables relate.
  Documentation: dm-integrity: Document default values.
  Documentation: dm-integrity: Document the meaning of "buffer".
  Documentation: dm-integrity: Fix minor grammatical error.
  dm integrity: Use %*ph for printing hexdump of a small buffer
  dm thin: disable discards for thin-pool if no_discard_passdown
  dm: remove stale/redundant dm_internal_{suspend,resume} prototypes in dm.h
  dm: skip dm-stats work in alloc_io() unless needed
  dm: avoid needless dm_io access if all IO accounting is disabled
  dm: support turning off block-core's io stats accounting
  ...

dm: get rid of GFP_NOIO workarounds for __vmalloc and kvmalloc

2023-06-27T20:06:54+00:00

In the past, the function __vmalloc didn't respect the GFP flags - it
allocated memory with the provided gfp flags, but it allocated page tables
with GFP_KERNEL. This was fixed in commit 451769ebb7e7 ("mm/vmalloc:
alloc GFP_NO{FS,IO} for vmalloc") so the memalloc_noio_{save,restore}
workaround is no longer needed.

The function kvmalloc didn't like flags different from GFP_KERNEL. This
was fixed in commit a421ef303008 ("mm: allow !GFP_KERNEL allocations
for kvmalloc"), so kvmalloc can now be called with GFP_NOIO.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer

Merge tag 'for-6.5/block-2023-06-23' of git://git.kernel.dk/linux

2023-06-26T19:47:20+00:00

Pull block updates from Jens Axboe:

 - NVMe pull request via Keith:
      - Various cleanups all around (Irvin, Chaitanya, Christophe)
      - Better struct packing (Christophe JAILLET)
      - Reduce controller error logs for optional commands (Keith)
      - Support for >=64KiB block sizes (Daniel Gomez)
      - Fabrics fixes and code organization (Max, Chaitanya, Daniel
        Wagner)

 - bcache updates via Coly:
      - Fix a race at init time (Mingzhe Zou)
      - Misc fixes and cleanups (Andrea, Thomas, Zheng, Ye)

 - use page pinning in the block layer for dio (David)

 - convert old block dio code to page pinning (David, Christoph)

 - cleanups for pktcdvd (Andy)

 - cleanups for rnbd (Guoqing)

 - use the unchecked __bio_add_page() for the initial single page
   additions (Johannes)

 - fix overflows in the Amiga partition handling code (Michael)

 - improve mq-deadline zoned device support (Bart)

 - keep passthrough requests out of the IO schedulers (Christoph, Ming)

 - improve support for flush requests, making them less special to deal
   with (Christoph)

 - add bdev holder ops and shutdown methods (Christoph)

 - fix the name_to_dev_t() situation and use cases (Christoph)

 - decouple the block open flags from fmode_t (Christoph)

 - ublk updates and cleanups, including adding user copy support (Ming)

 - BFQ sanity checking (Bart)

 - convert brd from radix to xarray (Pankaj)

 - constify various structures (Thomas, Ivan)

 - more fine grained persistent reservation ioctl capability checks
   (Jingbo)

 - misc fixes and cleanups (Arnd, Azeem, Demi, Ed, Hengqi, Hou, Jan,
   Jordy, Li, Min, Yu, Zhong, Waiman)

* tag 'for-6.5/block-2023-06-23' of git://git.kernel.dk/linux: (266 commits)
  scsi/sg: don't grab scsi host module reference
  ext4: Fix warning in blkdev_put()
  block: don't return -EINVAL for not found names in devt_from_devname
  cdrom: Fix spectre-v1 gadget
  block: Improve kernel-doc headers
  blk-mq: don't insert passthrough request into sw queue
  bsg: make bsg_class a static const structure
  ublk: make ublk_chr_class a static const structure
  aoe: make aoe_class a static const structure
  block/rnbd: make all 'class' structures const
  block: fix the exclusive open mask in disk_scan_partitions
  block: add overflow checks for Amiga partition support
  block: change all __u32 annotations to __be32 in affs_hardblocks.h
  block: fix signed int overflow in Amiga partition support
  block: add capacity validation in bdev_add_partition()
  block: fine-granular CAP_SYS_ADMIN for Persistent Reservation
  block: disallow Persistent Reservation on partitions
  reiserfs: fix blkdev_put() warning from release_journal_dev()
  block: fix wrong mode for blkdev_get_by_dev() from disk_scan_partitions()
  block: document the holder argument to blkdev_get_by_path
  ...

dm ioctl: Refuse to create device named "." or ".."

2023-06-23T14:31:52+00:00

Using either of these is going to greatly confuse userspace, as they are
not valid symlink names and so creating the usual /dev/mapper/NAME
symlink will not be possible.  As creating a device with either of these
names is almost certainly a userspace bug, just error out.

Signed-off-by: Demi Marie Obenour 
Signed-off-by: Mike Snitzer

dm ioctl: Refuse to create device named "control"

2023-06-23T14:31:51+00:00

Typical userspace setups create a symlink under /dev/mapper with the
name of the device, but /dev/mapper/control is reserved for DM's control
device.  Therefore, trying to create such a device is almost certain to
be a userspace bug.

Signed-off-by: Demi Marie Obenour 
Signed-off-by: Mike Snitzer