linux/Documentation/admin-guide/device-mapper
Shukai Ni 68c5c42567 dm-integrity: replace forgeable discard filler with a keyed sector marker
The discard-block check in dm_integrity_rw_tag() treats a stored tag
of all 0xf6 bytes (DISCARD_FILLER) as proof a block was discarded and
skips HMAC verification. allow_discards is only accepted in
dm-integrity's standalone mode. An attacker with raw write access to
the backing device, but without the integrity key, can stamp any block
with an all-0xf6 tag and have it served as authentic.

Add a new "allow_discards_keyed" target argument that marks discarded
blocks with a keyed checksum of (salt || sector) instead, computed by
integrity_discard_checksum().

Fixes: 84597a44a9 ("dm integrity: add optional discard support")
Co-developed-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be>
Signed-off-by: Jo Van Bulck <jo.vanbulck@cs.kuleuven.be>
Signed-off-by: Shukai Ni <shukai.ni@kuleuven.be>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
2026-08-03 17:46:40 +02:00
..
cache-policies.rst Documentation: admin-guide: correct spelling 2023-02-02 11:04:42 -07:00
cache.rst
delay.rst docs: device-mapper: fixed spelling mistakes in documentation 2025-08-19 11:12:50 +02:00
dm-clone.rst dm: add clone target 2019-09-12 09:32:31 -04:00
dm-crypt.rst dm-crypt: Document integrity_key_size option. 2025-02-03 14:10:10 +01:00
dm-dust.rst dm dust: add interface to list all badblocks 2020-07-20 11:17:41 -04:00
dm-ebs.rst Documentation: admin-guide: correct spelling 2023-02-02 11:04:42 -07:00
dm-flakey.rst dm flakey: introduce random_read_corrupt and random_write_corrupt options 2023-06-16 18:24:13 -04:00
dm-ima.rst dm-integrity: replace forgeable discard filler with a keyed sector marker 2026-08-03 17:46:40 +02:00
dm-init.rst dm init: add dm-mod.waitfor to wait for asynchronously probed block devices 2022-12-02 17:37:45 -05:00
dm-inlinecrypt.rst docs: device-mapper: dm-inlinecrypt: fix 'bellow' spelling 2026-07-28 11:06:50 +02:00
dm-integrity.rst dm-integrity: replace forgeable discard filler with a keyed sector marker 2026-08-03 17:46:40 +02:00
dm-io.rst
dm-log.rst
dm-pcache.rst dm-pcache: add persistent cache target in device-mapper 2025-08-25 15:25:29 +02:00
dm-queue-length.rst
dm-raid.rst dm-raid: fix typo in documentation 2026-01-02 15:03:53 +01:00
dm-service-time.rst
dm-uevent.rst
dm-zoned.rst Documentation: admin-guide: correct spelling 2023-02-02 11:04:42 -07:00
era.rst
index.rst dm: add documentation for dm-inlinecrypt target 2026-05-18 14:26:27 +02:00
kcopyd.rst
linear.rst
log-writes.rst
persistent-data.rst
snapshot.rst
statistics.rst
striped.rst
switch.rst
thin-provisioning.rst dm-thin: update the documentation 2025-07-31 15:43:30 +02:00
unstriped.rst Documentation: admin-guide: correct spelling 2023-02-02 11:04:42 -07:00
vdo-design.rst docs: device-mapper: fix typos in delay.rst and vdo-design.rst 2025-08-19 11:12:49 +02:00
vdo.rst dm-vdo: Promote dm-vdo title to title heading 2025-08-19 11:12:50 +02:00
verity.rst dm-verity-fec: improve documentation for Forward Error Correction 2026-03-09 15:11:50 +01:00
writecache.rst dm writecache: count number of blocks discarded, not number of discard bios 2022-07-14 15:54:46 -04:00
zero.rst