Signed-off-by: Mike Snitzer <snitzer@kernel.org>

"struct bvec_iter" is defined with the __packed attribute, so it is
aligned on a single byte. On X86 (and on other architectures that support
unaligned addresses in hardware), "struct bvec_iter" is accessed using the
8-byte and 4-byte memory instructions, however these instructions are less
efficient if they operate on unaligned addresses.

(on RISC machines that don't have unaligned access in hardware, GCC
generates byte-by-byte accesses that are very inefficient - see [1])

This commit reorders the entries in "struct dm_verity_io" and "struct
convert_context", so that "struct bvec_iter" is aligned on 8 bytes.

[1] https://lore.kernel.org/all/ZcLuWUNRZadJr0tQ@fedora/T/

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

If a userspace process reads (with O_DIRECT) multiple blocks into the same
buffer, dm-crypt reports an authentication error [1]. The error is
reported in a log and it may cause RAID leg being kicked out of the
array.

This commit fixes dm-crypt, so that if integrity verification fails, the
data is read again into a kernel buffer (where userspace can't modify it)
and the integrity tag is rechecked. If the recheck succeeds, the content
of the kernel buffer is copied into the user buffer; if the recheck fails,
an integrity error is reported.

[1] https://people.redhat.com/~mpatocka/testcases/blk-auth-modify/read2.c

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

It was said that authenticated encryption could produce invalid tag when
the data that is being encrypted is modified [1]. So, fix this problem by
copying the data into the clone bio first and then encrypt them inside the
clone bio.

This may reduce performance, but it is needed to prevent the user from
corrupting the device by writing data with O_DIRECT and modifying them at
the same time.

[1] https://lore.kernel.org/all/20240207004723.GA35324@sol.localdomain/T/

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

Tasklets have an inherent problem with memory corruption. The function
tasklet_action_common calls tasklet_trylock, then it calls the tasklet
callback and then it calls tasklet_unlock. If the tasklet callback frees
the structure that contains the tasklet or if it calls some code that may
free it, tasklet_unlock will write into free memory.

The commits 8e14f610159d and d9a02e016aaf try to fix it for dm-crypt, but
it is not a sufficient fix and the data corruption can still happen [1].
There is no fix for dm-verity and dm-verity will write into free memory
with every tasklet-processed bio.

There will be atomic workqueues implemented in the kernel 6.9 [2]. They
will have better interface and they will not suffer from the memory
corruption problem.

But we need something that stops the memory corruption now and that can be
backported to the stable kernels. So, I'm proposing this commit that
disables tasklets in both dm-crypt and dm-verity. This commit doesn't
remove the tasklet support, because the tasklet code will be reused when
atomic workqueues will be implemented.

[1] https://lore.kernel.org/all/d390d7ee-f142-44d3-822a-87949e14608b@suse.de/T/
[2] https://lore.kernel.org/lkml/20240130091300.2968534-1-tj@kernel.org/

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 39d42fa96ba1b ("dm crypt: add flags to optionally bypass kcryptd workqueues")
Fixes: 5721d4e5a9cdb ("dm verity: Add optional "try_verify_in_tasklet" feature")
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

commit 23baf831a32c ("mm, treewide: redefine MAX_ORDER sanely") has
changed the definition of MAX_ORDER to be inclusive.  This has caused
issues with code that was not yet upstream and depended on the previous
definition.

To draw attention to the altered meaning of the define, rename MAX_ORDER
to MAX_PAGE_ORDER.

Link: https://lkml.kernel.org/r/20231228144704.14033-2-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Commit 23baf831a32c ("mm, treewide: redefine MAX_ORDER sanely")
changed the meaning of MAX_ORDER from exclusive to inclusive. So, we
can allocate compound pages with up to 1 << MAX_ORDER pages.

Reflect this change in dm-crypt and start trying to allocate compound
pages with MAX_ORDER.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

Pull device mapper updates from Mike Snitzer:

 - Update DM core to directly call the map function for both the linear
   and stripe targets; which are provided by DM core

 - Various updates to use new safer string functions

 - Update DM core to respect REQ_NOWAIT flag in normal bios so that
   memory allocations are always attempted with GFP_NOWAIT

 - Add Mikulas Patocka to MAINTAINERS as a DM maintainer!

 - Improve DM delay target's handling of short delays (< 50ms) by using
   a kthread to check expiration of IOs rather than timers and a wq

 - Update the DM error target so that it works with zoned storage. This
   helps xfstests to provide proper IO error handling coverage when
   testing a filesystem with native zoned storage support

 - Update both DM crypt and integrity targets to improve performance by
   using crypto_shash_digest() rather than init+update+final sequence

 - Fix DM crypt target by backfilling missing memory allocation
   accounting for compound pages

* tag 'for-6.7/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm crypt: account large pages in cc->n_allocated_pages
  dm integrity: use crypto_shash_digest() in sb_mac()
  dm crypt: use crypto_shash_digest() in crypt_iv_tcw_whitening()
  dm error: Add support for zoned block devices
  dm delay: for short delays, use kthread instead of timers and wq
  MAINTAINERS: add Mikulas Patocka as a DM maintainer
  dm: respect REQ_NOWAIT flag in normal bios issued to DM
  dm: enhance alloc_multiple_bios() to be more versatile
  dm: make __send_duplicate_bios return unsigned int
  dm log userspace: replace deprecated strncpy with strscpy
  dm ioctl: replace deprecated strncpy with strscpy_pad
  dm crypt: replace open-coded kmemdup_nul
  dm cache metadata: replace deprecated strncpy with strscpy
  dm: shortcut the calls to linear_map and stripe_map

The commit 5054e778fcd9c ("dm crypt: allocate compound pages if
possible") changed dm-crypt to use compound pages to improve
performance. Unfortunately, there was an oversight: the allocation of
compound pages was not accounted at all. Normal pages are accounted in
a percpu counter cc->n_allocated_pages and dm-crypt is limited to
allocate at most 2% of memory. Because compound pages were not
accounted at all, dm-crypt could allocate memory over the 2% limit.

Fix this by adding the accounting of compound pages, so that memory
consumption of dm-crypt is properly limited.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Fixes: 5054e778fcd9c ("dm crypt: allocate compound pages if possible")
Cc: stable@vger.kernel.org	# v6.5+
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

Simplify crypt_iv_tcw_whitening() by using crypto_shash_digest() instead
of an init+update+final sequence.  This should also improve performance.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>