In the Linux kernel, the following vulnerability has been resolved:
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().
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().
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 17 Sep 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: 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(). | |
| Title | dm-integrity: replace forgeable discard filler with a keyed sector marker | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-17T16:08:46.805Z
Reserved: 2026-09-11T19:38:34.803Z
Link: CVE-2026-90333
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-17T17:17:31.830
Modified: 2026-09-17T17:17:31.830
Link: CVE-2026-90333
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.