linux/drivers/md
Milan Broz fc89438866 dm-verity FEC: Fix RS FEC repair for roots unaligned to block size (take 2)
commit 6df90c02ba upstream.

This patch fixes an issue that was fixed in the commit
  df7b59ba92 ("dm verity: fix FEC for RS roots unaligned to block size")
but later broken again in the commit
  8ca7cab82b ("dm verity fec: fix misaligned RS roots IO")

If the Reed-Solomon roots setting spans multiple blocks, the code does not
use proper parity bytes and randomly fails to repair even trivial errors.

This bug cannot happen if the sector size is multiple of RS roots
setting (Android case with roots 2).

The previous solution was to find a dm-bufio block size that is multiple
of the device sector size and roots size. Unfortunately, the optimization
in commit 8ca7cab82b ("dm verity fec: fix misaligned RS roots IO")
is incorrect and uses data block size for some roots (for example, it uses
4096 block size for roots = 20).

This patch uses a different approach:

 - It always uses a configured data block size for dm-bufio to avoid
 possible misaligned IOs.

 - and it caches the processed parity bytes, so it can join it
 if it spans two blocks.

As the RS calculation is called only if an error is detected and
the process is computationally intensive, copying a few more bytes
should not introduce performance issues.

The issue was reported to cryptsetup with trivial reproducer
  https://gitlab.com/cryptsetup/cryptsetup/-/issues/923

Reproducer (with roots=20):

 # create verity device with RS FEC
 dd if=/dev/urandom of=data.img bs=4096 count=8 status=none
 veritysetup format data.img hash.img --fec-device=fec.img --fec-roots=20 | \
 awk '/^Root hash/{ print $3 }' >roothash

 # create an erasure that should always be repairable with this roots setting
 dd if=/dev/zero of=data.img conv=notrunc bs=1 count=4 seek=4 status=none

 # try to read it through dm-verity
 veritysetup open data.img test hash.img --fec-device=fec.img --fec-roots=20 $(cat roothash)
 dd if=/dev/mapper/test of=/dev/null bs=4096 status=noxfer

 Even now the log says it cannot repair it:
   : verity-fec: 7:1: FEC 0: failed to correct: -74
   : device-mapper: verity: 7:1: data block 0 is corrupted
   ...

With this fix, errors are properly repaired.
   : verity-fec: 7:1: FEC 0: corrected 4 errors

Signed-off-by: Milan Broz <gmazyland@gmail.com>
Fixes: 8ca7cab82b ("dm verity fec: fix misaligned RS roots IO")
Cc: stable@vger.kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
History 2025-01-17 13:40:46 +01:00
..
bcache bcache: revert replacing IS_ERR_OR_NULL with IS_ERR again 2024-12-14 20:03:26 +01:00
dm-vdo move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
persistent-data dm array: fix cursor index when skipping across block boundaries 2025-01-17 13:40:34 +01:00
dm-audit.c dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-audit.h dm: introduce audit event module for device mapper 2021-10-27 16:53:47 -04:00
dm-bio-prison-v1.c dm: update relevant MODULE_AUTHOR entries to latest dm-devel mailing list 2024-02-20 14:22:55 -05:00
dm-bio-prison-v1.h dm bio prison v1: add dm_cell_key_has_valid_range 2023-03-30 15:57:51 -04:00
dm-bio-prison-v2.c dm: use bio_list_merge_init 2024-04-01 11:53:37 -06:00
dm-bio-prison-v2.h dm: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
dm-bio-record.h dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-bufio.c dm-bufio: fix warnings about duplicate slab caches 2024-11-11 17:04:18 +01:00
dm-builtin.c dm: adjust EXPORT_SYMBOL() to follow functions immediately 2023-02-14 14:23:07 -05:00
dm-cache-background-tracker.c dm-cache: fix warnings about duplicate slab caches 2024-11-11 17:04:39 +01:00
dm-cache-background-tracker.h dm-cache: fix warnings about duplicate slab caches 2024-11-11 17:04:39 +01:00
dm-cache-block-types.h dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-cache-metadata.c dm: Constify struct dm_block_validator 2024-07-19 12:08:15 +02:00
dm-cache-metadata.h dm: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
dm-cache-policy-internal.h dm: add missing empty lines 2023-02-14 14:23:06 -05:00
dm-cache-policy-smq.c dm: update relevant MODULE_AUTHOR entries to latest dm-devel mailing list 2024-02-20 14:22:55 -05:00
dm-cache-policy.c dm: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
dm-cache-policy.h dm: address indent/space issues 2023-02-14 14:23:06 -05:00
dm-cache-target.c dm-cache: fix warnings about duplicate slab caches 2024-11-11 17:04:39 +01:00
dm-clone-metadata.c dm: Make use of __assign_bit() API 2024-09-02 16:53:53 +02:00
dm-clone-metadata.h dm clone metadata: Fix return type of dm_clone_nr_of_hydrated_regions() 2020-03-27 14:42:51 -04:00
dm-clone-target.c dm: stop using blk_limits_io_{min,opt} 2024-07-10 13:10:06 +02:00
dm-core.h dm: optimize flushes 2024-06-26 11:32:39 -04:00
dm-crypt.c move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
dm-delay.c dm-delay: remove timer_lock 2024-05-09 09:10:58 -04:00
dm-dust.c dm: update relevant MODULE_AUTHOR entries to latest dm-devel mailing list 2024-02-20 14:22:55 -05:00
dm-ebs-target.c dm-ebs: don't set the flag DM_TARGET_PASSES_INTEGRITY 2025-01-17 13:40:46 +01:00
dm-era-target.c dm: Constify struct dm_block_validator 2024-07-19 12:08:15 +02:00
dm-exception-store.c dm: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
dm-exception-store.h dm: avoid spaces before function arguments or in favour of tabs 2023-02-14 14:23:06 -05:00
dm-flakey.c dm: update relevant MODULE_AUTHOR entries to latest dm-devel mailing list 2024-02-20 14:22:55 -05:00
dm-ima.c dm: avoid inline filenames 2023-02-14 14:23:07 -05:00
dm-ima.h dm: avoid inline filenames 2023-02-14 14:23:07 -05:00
dm-init.c dm init: Handle minors larger than 255 2024-07-02 20:53:41 +02:00
dm-integrity.c - Misc VDO fixes 2024-09-27 09:12:51 -07:00
dm-io-rewind.c dm: avoid void function return statements 2023-02-14 14:23:07 -05:00
dm-io-tracker.h dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-io.c dm io: remove code duplication between sync_io and aysnc_io 2024-07-02 12:00:43 +02:00
dm-ioctl.c dm resume: don't return EINVAL when signalled 2024-08-13 13:51:34 +02:00
dm-kcopyd.c dm io: Support IO priority 2024-02-20 14:22:51 -05:00
dm-linear.c dm: optimize flushes 2024-06-26 11:32:39 -04:00
dm-log-userspace-base.c dm: update relevant MODULE_AUTHOR entries to latest dm-devel mailing list 2024-02-20 14:22:55 -05:00
dm-log-userspace-transfer.c dm: avoid split of quoted strings where possible 2023-02-14 14:23:07 -05:00
dm-log-userspace-transfer.h dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-log-writes.c dm: always manage discard support in terms of max_hw_discard_sectors 2024-05-20 15:51:19 -04:00
dm-log.c dm: update relevant MODULE_AUTHOR entries to latest dm-devel mailing list 2024-02-20 14:22:55 -05:00
dm-mpath.c dm mpath: don't call dm_get_device in multipath_message 2024-07-10 13:10:06 +02:00
dm-mpath.h dm: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
dm-path-selector.c dm: adjust EXPORT_SYMBOL() to follow functions immediately 2023-02-14 14:23:07 -05:00
dm-path-selector.h dm: avoid spaces before function arguments or in favour of tabs 2023-02-14 14:23:06 -05:00
dm-ps-historical-service-time.c dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-ps-io-affinity.c dm: address space issues relative to switch/while/for/... 2023-02-14 14:23:06 -05:00
dm-ps-queue-length.c dm: avoid spaces before function arguments or in favour of tabs 2023-02-14 14:23:06 -05:00
dm-ps-round-robin.c dm: update relevant MODULE_AUTHOR entries to latest dm-devel mailing list 2024-02-20 14:22:55 -05:00
dm-ps-service-time.c dm: avoid spaces before function arguments or in favour of tabs 2023-02-14 14:23:06 -05:00
dm-raid.c - Misc VDO fixes 2024-09-27 09:12:51 -07:00
dm-raid1.c dm io: Support IO priority 2024-02-20 14:22:51 -05:00
dm-region-hash.c dm: update relevant MODULE_AUTHOR entries to latest dm-devel mailing list 2024-02-20 14:22:55 -05:00
dm-rq.c Revert "dm: requeue IO if mapping table not yet available" 2024-09-15 21:02:54 +02:00
dm-rq.h dm: change "unsigned" to "unsigned int" 2023-02-14 14:23:06 -05:00
dm-snap-persistent.c dm io: Support IO priority 2024-02-20 14:22:51 -05:00
dm-snap-transient.c dm: avoid split of quoted strings where possible 2023-02-14 14:23:07 -05:00
dm-snap.c dm: always manage discard support in terms of max_hw_discard_sectors 2024-05-20 15:51:19 -04:00
dm-stats.c dm stats: limit the number of entries 2024-01-30 14:06:44 -05:00
dm-stats.h dm stats: check for and propagate alloc_percpu failure 2023-03-16 13:37:06 -04:00
dm-stripe.c dm: stop using blk_limits_io_{min,opt} 2024-07-10 13:10:06 +02:00
dm-switch.c dm: add helper macro for simple DM target module init and exit 2023-04-11 12:09:08 -04:00
dm-sysfs.c dm sysfs: make kobj_type structure constant 2023-02-14 14:23:08 -05:00
dm-table.c dm: introduce the target flag mempool_needs_integrity 2024-07-12 12:39:06 -04:00
dm-target.c dm: always manage discard support in terms of max_hw_discard_sectors 2024-05-20 15:51:19 -04:00
dm-thin-metadata.c dm: Constify struct dm_block_validator 2024-07-19 12:08:15 +02:00
dm-thin-metadata.h dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-thin.c dm thin: make get_first_thin use rcu-safe list first function 2025-01-17 13:40:45 +01:00
dm-uevent.c dm: avoid spaces before function arguments or in favour of tabs 2023-02-14 14:23:06 -05:00
dm-uevent.h dm: fix undue/missing spaces 2023-02-14 14:23:06 -05:00
dm-unstripe.c dm-unstriped: cast an operand to sector_t to prevent potential uint32_t overflow 2024-11-04 17:34:56 +01:00
dm-verity-fec.c dm-verity FEC: Fix RS FEC repair for roots unaligned to block size (take 2) 2025-01-17 13:40:46 +01:00
dm-verity-fec.h dm-verity: always "map" the data blocks 2024-07-03 21:41:11 +02:00
dm-verity-loadpin.c dm: verity-loadpin: Add NULL pointer check for 'bdev' parameter 2023-06-28 10:43:04 -07:00
dm-verity-target.c dm-verity: don't crash if panic_on_corruption is not selected 2024-11-04 17:39:23 +01:00
dm-verity-verify-sig.c dm verity: fallback to platform keyring also if key in trusted keyring is rejected 2024-09-26 17:27:08 +02:00
dm-verity-verify-sig.h dm: add missing SPDX-License-Indentifiers 2023-02-14 14:23:06 -05:00
dm-verity.h dm-verity: don't crash if panic_on_corruption is not selected 2024-11-04 17:39:23 +01:00
dm-writecache.c dm: update relevant MODULE_AUTHOR entries to latest dm-devel mailing list 2024-02-20 14:22:55 -05:00
dm-zero.c dm: always manage discard support in terms of max_hw_discard_sectors 2024-05-20 15:51:19 -04:00
dm-zone.c dm: handle REQ_OP_ZONE_RESET_ALL 2024-07-05 00:42:04 -06:00
dm-zoned-metadata.c block: remove gfp_flags from blkdev_zone_mgmt 2024-02-12 08:41:16 -07:00
dm-zoned-reclaim.c dm: Fix dm-zoned-reclaim zone write pointer alignment 2024-12-19 18:13:00 +01:00
dm-zoned-target.c dm: stop using blk_limits_io_{min,opt} 2024-07-10 13:10:06 +02:00
dm-zoned.h dm/dm-zoned: Use the enum req_op type 2022-07-14 12:14:31 -06:00
dm.c dm: fix a crash if blk_alloc_disk fails 2024-10-15 13:37:17 +02:00
dm.h dm: Remove unused declaration and empty definition "dm_zone_map_bio" 2024-08-21 13:12:12 +02:00
Kconfig dm verity: add support for signature verification with platform keyring 2024-07-03 21:41:11 +02:00
Makefile dm vdo: use a proper Makefile for dm-vdo 2024-02-20 13:43:17 -05:00
md-autodetect.c md: Remove deprecated CONFIG_MD_LINEAR 2023-12-19 10:16:51 -08:00
md-bitmap.c md/md-bitmap: Add missing destroy_work_on_stack() 2024-12-09 10:40:56 +01:00
md-bitmap.h md/md-bitmap: make in memory structure internal 2024-08-27 12:43:16 -07:00
md-cluster.c md/md-bitmap: make in memory structure internal 2024-08-27 12:43:16 -07:00
md-cluster.h md-cluster: fix no recovery job when adding/re-adding a disk 2024-07-12 01:30:18 +00:00
md.c md: ensure child flush IO does not affect origin bio->bi_status 2024-10-17 11:35:36 -07:00
md.h Merge branch 'md-6.12-bitmap' into md-6.12 2024-08-28 14:55:57 -07:00
raid0.c md: set md-specific flags for all queue limits 2024-06-26 09:37:35 -06:00
raid0.h md/raid0: add discard support for the 'original' layout 2023-06-30 15:43:50 -07:00
raid1-10.c md/md-bitmap: merge md_bitmap_enabled() into bitmap_operations 2024-08-27 12:43:16 -07:00
raid1.c for-6.12/block-20240913 2024-09-16 13:33:06 +02:00
raid1.h md/raid1: record nonrot rdevs while adding/removing rdevs to conf 2024-02-29 22:49:45 -08:00
raid5-cache.c md/raid5: use wait_on_bit() for R5_Overlap 2024-08-29 09:37:10 -07:00
raid5-log.h md/raid5-ppl: Drop unused argument from ppl_handle_flush_request() 2022-08-02 17:14:31 -06:00
raid5-ppl.c md: remove mddev->queue 2024-03-06 08:59:53 -08:00
raid5.c md/raid5: Wait sync io to finish before changing group cnt 2024-12-09 10:40:56 +01:00
raid5.h md/raid5: rename wait_for_overlap to wait_for_reshape 2024-08-29 09:37:10 -07:00
raid10.c md/raid10: fix null ptr dereference in raid10_size() 2024-10-17 11:43:43 -07:00
raid10.h md/raid10: switch to use md_account_bio() for io accounting 2023-07-27 00:13:29 -07:00