Description
In the Linux kernel, the following vulnerability has been resolved:

dm-integrity: fix buffer overflow with keyed discard

Since commit 68c5c42567bc ("dm-integrity: replace forgeable discard
filler with a keyed sector marker"), integrity_metadata computes a
checksum for every discarded block into the "checksums" buffer.
integrity_sector_checksum always writes the whole digest. So if the tag
size is smaller than the digest size, the checksum of the last block
that fits into the buffer is written past the end of it. For example,
with hmac(sha256) and tag size 16, a 4MiB discard writes 16 bytes past
the kmalloc'ed page.

Fix this by subtracting extra_space from the buffer size when computing
max_blocks, like we do for writes.
Published: 2026-09-17
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

No analysis available yet.

Remediation

No remediation available yet.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

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: fix buffer overflow with keyed discard Since commit 68c5c42567bc ("dm-integrity: replace forgeable discard filler with a keyed sector marker"), integrity_metadata computes a checksum for every discarded block into the "checksums" buffer. integrity_sector_checksum always writes the whole digest. So if the tag size is smaller than the digest size, the checksum of the last block that fits into the buffer is written past the end of it. For example, with hmac(sha256) and tag size 16, a 4MiB discard writes 16 bytes past the kmalloc'ed page. Fix this by subtracting extra_space from the buffer size when computing max_blocks, like we do for writes.
Title dm-integrity: fix buffer overflow with keyed discard
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-09-17T16:05:38.281Z

Reserved: 2026-09-11T19:38:34.783Z

Link: CVE-2026-90052

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-17T17:16:53.610

Modified: 2026-09-17T17:16:53.610

Link: CVE-2026-90052

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.